the athlete's shoulder || the role of the scapula in rehabilitation

671

The body functions as an integrated system in all aspects of sport and work. This integrated system allows variability so that we can respond to specifi c tasks in an effi cient manner. Understanding how the entire system works as a functional unit within its environment is indispensable for appropriate evaluation and intervention to restore patients to their full functional level. Individual patients develop movement patterns and resting postures dependent on their physical characteristics, the demands of the particular task, the environment of the task, and their psychological state. The goal of the treating clinician is to identify these factors as they relate to physical impairments, functional limitations, and particular pathology. Once the factors are identifi ed, there are several ways to intervene. Through our clinical experience we have found that exercises that inte-grate the entire body and address scapular motion and control have helped our patients return to their normal function. The primary goals of this chapter are to describe our clinical assessment of the scapula and to provide our rehabilitation approach in the upper extremity of a throw-ing athlete.

BIOMECHANICS

In overhead throwing sports the goal is to throw the ball accurately, for a great distance or at maximum speeds. To impart the necessary force to the ball the entire body is used sequentially in a general proximal-to-distal man-ner.1-3 This system is commonly referred to as the kinetic chain, which is a coordinated activation of body segments (e.g., leg, trunk, upper arm) that are connected at articula-tions. To throw a ball at a high rate of speed, the proximal segments of the kinetic chain initiate motion of the entire system. As a proximal segment, such as the front leg of a pitcher, decelerates, momentum is transferred to the next distal segment, the trunk. This process continues through-out the entire kinetic chain until the ball is released. As momentum is transferred to the arm segments (which are smaller in mass), the velocity of the segment increases.4,5 By using the summation of the entire kinetic chain, all seg-ments contribute to the performance of the task. Segment drop out or kinetic chain breakage requires other seg-ments to increase force production or increase loads in distal segments.4,6,7 This is why the evaluation of the in-jured patient has to be so comprehensive. If the examiner focuses on a sore shoulder and does not discover that the athlete has a weak front leg, the primary culprit of the

clinical symptoms has not been identifi ed, and ultimately the rehabilitation program will fail. Lower-body strength has been positively correlated with terminal ball velocity and is more highly correlated than upper body strength.8

A critical segment or link in transferring this force is the scapula, which is the attachment site for approximately 17 muscles involved in upper-extremity motion. Many of the muscles that attach to the scapula, such as the trape-zius, serratus anterior, latissimus dorsi, and rhomboids, have proximal attachments to the axial skeleton and are instrumental in maximizing mobility of the upper extrem-ity. The interaction of trunk, scapular, and humeral motion provides a dynamic linked system that is used in many ways in numerous sport activities, from providing a stable base for archery to providing a very mobile system in throwing. The motion provided by the scapula allows the glenohumeral articulation to be the most mobile joint in the human body.9 The scapula provides a dynamic base for humeral motion. The interactive coupling of the scapula and humerus, scapulohumeral rhythm, maintains an opti-mal muscle length relationship in the rotator cuff muscu-lature and avoids excessive tension on the glenohumeral ligaments.10,11

This sequencing of events not only occurs biomechanically but also occurs in the neuromuscular control of human motion. Activation of proximal trunk musculature, such as the transverse abdominus and multifi dius muscles, has been demonstrated to precede activation of distal muscles, such as the anterior deltoid, to prepare the body for posi-tional changes due to the moving segment.12,13 These an-ticipatory postural adjustments occur both in sitting and standing and occur regardless of the direction of the movement.14,15 These normal motor control patterns are exaggerated in our approach to shoulder rehabilitation by incorporating the entire kinetic chain and focusing the patient’s abilities to activate proximal muscle to control the trunk and scapula before placing demands on more distal musculature.

Proximal control for distal mobility is a basic concept taught in many biomechanics and kinesiology courses. One of us (WBK) put this to work clinically in the 1980s when he started investigating the role of the scapula in upper-extremity pathologies. In observing a swimmer with chronic shoulder pain from the rear while she was wearing a swimming suit, he noted signifi cant scapular winging.

CHAPTER 50 The Role of the Scapula in Rehabilitation

Tim L. Uhl and W. Ben Kibler

Ch50_671-684-F06701.indd 671Ch50_671-684-F06701.indd 671 9/19/08 7:15:02 PM9/19/08 7:15:02 PM

672 THE ATHLETE’S SHOULDER

By evaluating and appreciating the relationship between symptoms of shoulder impingement and proximal sca-pular dysfunction, he was able to identify all physical im-pairments contributing to her pathology. The assessment of scapular dysfunction as part of the clinical examination of the upper extremity is still a relatively new idea to many clinicians. However, since the 1980s the literature on the role of the scapula and the surrounding muscular in shoul-der dysfunction and the importance of considering the scapula in treatment interventions has dramatically in-creased. A Medline search of the word scapula between 1966 and 1988 (22 years) retrieved 1647 citations; the same search between the years 1989 and 2006 (17 years) returned 2281 citations.

Advances in biomechanical techniques that allow evalua-tion of scapular motion have opened many doors of inves-tigation. Critical research by Karduna and McClure dem-onstrated that scapular motion could be evaluated with skin sensors attached to the scapula, increasing our under-standing of scapular biomechanics. In a series of studies, they instrumented subjects with electromagnetic sensors attached to the skin overlying the scapula and to bone pins placed in the spine of the scapula. They demonstrated that sensors attached to the skin could accurately measure scapular motion during arm motions.16,17 From their re-search they identifi ed that the scapula rotates about three axes; upward and downward rotation, internal and exter-nal rotation, and anterior and posterior tilt (Fig. 50-1).

Karduna and McClure found that at maximal humeral el-evation in the scapular plane the scapula upwardly rotated 50 ± 5 degrees, externally rotated 24 ± 13 degrees, and posteriorly tilted 30 ± 13 degrees. This motion occurs si-multaneously in all three planes, but they demonstrated that the greatest amount of external rotation and posterior tilting occurred above 90 degrees of humeral elevation.17 In addition to these rotations, translatory motion of the scapula occurs. Superior scapular translation along the thoracic wall occurs during forward reaching tasks. Ante-rior translation around the thoracic wall occurs during forward reaching tasks, and the scapula translates posteri-orly during pulling tasks. Medial and lateral translation, the third translation, is limited due to the clavicle strut effect and does not occur unless there is a high-grade acromioclavicular joint separation.17

Understanding the anatomy and biomechanics of the scapula provides the clinician with a fi rm base to better understand the function and the evaluation of scapular dysfunction. Chapters 1 and 2 address the anatomy and biomechanics of the shoulder complex thoroughly; therefore, we direct the reader to those chapters for further information.

ASSESSMENT OF SCAPULAR DYSKINESIS

The term scapular dyskinesis was coined by JP Warner. He found scapular dyskinesis in 64% of his patients with gle-nohumeral instability and in nearly 100% of his patients with rotator cuff impingement.18 Several factors can con-tribute to scapular dyskinesis. They are categorized into two groups: proximal causes and distal causes.19 Proximal categories include neuropathy,20,21 muscle weakness,22 muscle tightness,23 muscle fatigue,24,25 pain,26 and loss of neuromuscular control,27,28 which can respond to physical therapy interventions. Distal categories include glenohu-meral pathology29-32 and acromioclavicular joint separa-tions, which usually require surgical intervention to return the patient to full function. Each of these potential factors needs to considered during physical examination of scap-ular dyskinesis.

The goals of the physical examination of the scapula are to determine the presence or absence of scapular dyskinesis, to evaluate proximal and distal causative factors, and to employ dynamic maneuvers to assess the effect of correction of dys-kinesis. The results of the examination help in establishing the complete diagnosis and in guiding rehabilitation.

PostureTo evaluate scapular dyskinesis, the scapula, spine, and clavicle must be adequately exposed and the examiner must view the patient from the posterior aspect.

Internal/external rotation

Upward/downwardrotation

Anterior/posteriortilt

Figure 50-1. This diagram illustrates the three rotational axes of the scapula and the motions that occur around them.


THE ROLE OF THE SCAPULA IN REHABILITATION 673

Observation of resting posture of the spine and scapula should be the fi rst assessment. Resting posture has been implemented as a cause of shoulder and neck pain.33 Thoracic kyphosis has been demonstrated to decrease scapular and humeral motion while also decreasing shoulder strength.34 Rounded shoulder posture is often present in athletes, such as weightlifters and swimmers, who have developed muscle imbalances due to their sport.35 One factor contributing to protracted shoulders can be a shortened or tight pectoralis minor. A short pectoralis minor has been demonstrated to reduce scapular motion during active arm elevation.36 An-other factor contributing to scapular dyskinesis is internal rotation defi ciency due to tight posterior structures of the glenohumeral joint. This can restrict humeral motion and potentially place increased compressive and tensile loads on glenohumeral tissues. Incorporation of legs and trunk obser-vation in a bipedal and single leg stance is important to evaluate core stability and the lower extremity balance.

The patient should perform a single leg squat. This allows the clinician to screen for poor trunk and hip control, which might need further isolated examination. In clinical assess-ment of throwing athletes, poor hip and trunk stability are commonly found in the presence of shoulder pain.32 The di-rect correlation is not currently known, but a signifi cant force contribution originating in the legs has been demonstrated.5,6,8 Therefore, proximal defi ciencies must be identifi ed so they can be addressed during the rehabilitation program.

Resting scapular position can be assessed with the pa-tient’s arms at the sides. Excessive scapular internal rota-tion and lateral translation will be noted as prominence of the medial scapular border. A semidynamic assessment of scapular position using a tape measure is called the lateral scapular slide.37 The distance between the inferior angle of the scapula and a thoracic spinous process is measured in three arm positions; at rest, hands on hips, and arms ab-ducted to 90 degrees and maximally internally rotated. A difference of greater than 1.5 cm suggests a loss of muscu-lar control of the involved shoulder.37 The ability to dis-criminate this difference in symptomatic and asymptom-atic subjects has been supported by Odom.38

Active Range of MotionAssessment of active and passive range of motion is critical in evaluating shoulder impairments. Assessment of dy-namic scapular motion allows the examiner to appreciate scapulohumeral rhythm during arm motion. This dynamic assessment can be facilitated by having the subject perform multiple3-10 repetitions of active arm elevation in both fl ex-ion and abduction. By watching the patient move slowly through the range of motion, subtle anomalies can be iden-tifi ed. Additionally, adding 2 to 5 lbs in the hand increases the distal load and can elicit more scapular dysfunction. A categorization of this dynamic scapular observation has been reported and found to have a moderate inter- and

intrarater reliability of 40% to 50%.39 The four categories described were normal, superior border pattern, medial border pattern, and inferior angle pattern (Box 50-1). These patterns of scapular motion have not been found to be associated with any specifi c glenohumeral injury. Further investigations into the patterns of scapular motion have demonstrated that altered scapular motion does not occur in isolation but more commonly occurs in combination. By modifying the categories to a simpler description of whether scapular dyskinesis is present or absent, the sensitivity of clinical observation reached 76% when compared with three-dimensional kinematic assessment of scapular mo-tion (unpublished data).

Corrective maneuvers during the assessment of dynamic scapular motion can help the clinician estimate the effect of the scapular dyskinesis. The scapular assistance test may be used in patients with impingement symptoms. The ex-aminer applies a fi rm upward rotation and posterior tilt to the scapula’s inferior angle and superior border as the patient elevates the arm (Fig. 50-2).40 The test is positive when the patient’s symptoms of a painful arc are reduced during active elevation with the scapula supported. The scapular assistance test validity has not been quantifi ed.

BOX 50-1. Scapular Dyskinesis System Used to Categorize Abnormal Scapular Motion

Inferior Angle Pattern (Type I)At rest, the inferior medial scapular border may be promi-nent dorsally. During arm motion, the predominant move-ment is that the inferior angle tilts dorsally and the acromion tilts ventrally over the top of the thorax. The axis of rotation for this pattern is in the horizontal plane.

Medial Border Pattern (Type II)At rest, the entire medial border may be prominent dor-sally. During arm motion, the predominant movement is that the medial scapular border tilts dorsally off the tho-rax. The axis of rotation is vertical in the frontal plane.

Superior Border Pattern (Type III)At rest, the superior border of the scapula may be ele-vated, and the scapula can also be anteriorly displaced. During motion, the predominant movement is that a shoulder shrug initiates movement without signifi cant winging of the scapula. The axis of this motion occurs in the sagittal plane.

Symmetrical Scapulohumeral Pattern (Type IV)At rest, the positions of both scapulae are relatively sym-metrical, taking into account that the dominant arm may be slightly lower. During arm motion, the scapulae rotate symmetrically upward so that the inferior angles translate laterally away from the midline and the scapular medial border remains fl ush against the thoracic wall. The re-verse occurs during lowering of the arm.



The scapular retraction test may be used in demonstrating rotator cuff weakness (Fig. 50-3).40 The test is positive when rotator cuff strength is increased during the scapular retraction test as compared with rotator cuff strength without the scapula retracted. If either test is positive, re-habilitation of scapular retraction or external rotation should precede rotator cuff–focused exercises.

Proximal StabilityProximal factors infl uencing scapular dyskinesis are critical components in evaluating and treating scapular problems. Proximal hip and trunk stability can be screened by having the subject stand on one leg. Poor balance and Trendelen-berg (hip-adducted) posture should be noted. A squat maneuver to 60 degrees of knee fl exion evaluates dynamic control of the pelvic region. Dramatic loss of hip control such as excessive pelvic rotation in any plane (Fig. 50-4) and poor balance indicates poor dynamic pelvic control

and merits further examination of hip and trunk muscular strength and fl exibility.41

StrengthScapular muscle strength can be screened with a wall push-up for gross serratus dysfunction such as is found in long thoracic palsy. A shoulder shrug has been demon-strated to be a valid assessment upper trapezius strength.42 The test originally described by Kendall43 for the lower trapezius has also been found to be a very good assess-ment of lower trapezius strength and preferentially acti-vates the lower trapezius muscle.42,44 The patient lies prone with arm abducted to 135 degrees and thumb pointing toward the ceiling. A force is applied to the scapula or to the arm to cause shoulder extension. A weak lower trapezius is diagnosed if the subject is unable to hold this position or unable to hold it against minimal resistance. The middle trapezius is best tested by position-ing the patient prone with elbow extended and shoulder externally rotated (thumb up) and applying a downward force at the forearm to make the patient produce scapular adduction.45 Various positions of prone horizontal abduc-tion to discriminate the rhomboids from other synergistic muscles have not been able to isolate rhomboid acti-vation.45 Therefore, weakness with shoulder horizontal abduction can be attributed to several muscles, including the middle trapezius and posterior deltoid, along with the rhomboids.

Figure 50-2. The scapular assistance test is positive when shoulder symptoms are reduced during the maneuver.

Figure 50-3. The scapular retraction test is positive when elevation strength is stronger with the scapula stabilized.

Figure 50-4. Single leg squat with poor hip stability.



All complete shoulder evaluations include testing of the rotator cuff musculature. A modifi cation of the supraspina-tus strength test, the scapular retraction test, has been proposed by one of us (WBK).40 The purpose of this test is to better determine if rotator cuff weakness is true or ap-parent. The test is performed by fi rst examining the strength of the supraspinatus in the typical manner. Then the pa-tient retracts the scapula and, with the assistance of the examiner, maintains scapular retraction. The test is positive when strength is improved in the retracted position. This is considered an apparent rotator cuff weakness but not a true weakness because the performance improves with ad-ditional stabilization of the proximal attachment of the supraspinatus, the scapula. A negative test indicates a true rotator cuff weakness if the patient’s strength did not im-prove with the scapula stabilized.40 Through the use of a hand-held dynamometer, the scapular retraction test has been found to improve elevation strength by 24% over the traditional empty can strength test for the supraspinatus.46

Following a complete examination of the shoulder includ-ing glenohumeral instability, labral pathology, tendinop-athy, and acromioclavicular and sternoclavicular joint integrity, a treatment plan to address scapular dysfunction is developed. The fi rst step in an effective intervention is a thorough understanding of normal function and identifi -cation of defi cits during the examination.47 This allows the clinician to develop a specifi c rehabilitation program.

REHABILITATION OF SCAPULAR DYSKINESIS

The body functions as an integrated system. Rehabilitation, like evaluation, needs to incorporate the entire functional unit. During rehabilitation our focus needs to shift from isolating the problem to providing interventions that ad-dress the athlete’s impairments and functional limitations. We take an integrated approach incorporating the kinetic-chain model, the motor-control pattern of proximal to distal activation, and many principles of proprioceptive neuro-muscular facilitation to achieve the goals of restoring func-tion. Consideration of the athlete’s impairments and envi-ronment must be integral to the intervention because the athlete is often attempting to return to the same activity that might have precipitated the initial injury.

From the comprehensive evaluation we have identifi ed physical impairments such as tight or weak musculature and specifi c functional limitations of the patient that are going to be addressed during the rehabilitation program. Often the fi rst two areas to address are posture and proxi-mal stability. As we have mentioned, proximal dysfunctions can contribute to scapular dyskinesis. The position of the spine is intimately involved with the position and motion of the scapula and the humerus.34,48 Therefore, we often address proximal control of the trunk with trunk extension

exercises to decrease thoracic kyphosis in concert with scapular retraction exercises.

PostureThoracic kyphosis reduces humeral elevation and limits normal scapular motion in such a manner to cause the scapula to be more protracted.34 A protracted scapula has been demonstrated by MRI to reduce the subacromial space49 and diminish humeral elevation strength.50 To ad-dress these common problems we recommend a program that facilitates trunk extension and scapular retraction. This can be accomplished in a variety of ways.

A dynamic exercise that is commonly attempted initially is called “elbows in the back pocket” (Fig. 50-5). This exercise starts with a forward fl exed trunk and protracted scapula and ends with the patient in thoracic extension and scapu-lar retraction. The patient is instructed to tuck the elbows into the back pocket during this maneuver and is closely watched to ensure he or she is getting good scapular re-traction without excessive lumbar lordosis. Key teaching points are not shrugging the shoulders and not overly ex-tending the lumbar spine.

If the back pocket exercise is too painful for the patient or the scapular control is not adequate, this exercise can be simplifi ed to a low row exercise (Fig. 50-6). This exercise also incorporates both trunk and scapular motion simulta-neously but has a smaller magnitude of motion and is

Figure 50-5. Trunk extension and scapular retraction.



more of an isometric exercise. The patient places the hand on either an immovable object (e.g., countertop) or uses a heavy elastic resistance. With the arm at the side, the pa-tient extends the shoulder and depresses the scapula as he or she steps forward with the ipsilateral leg. This exercise has been found to produce low to moderate activation of the serratus anterior, lower trapezius, and posterior deltoid without signifi cant activation of the upper trapezius (un-published observation).

Both of these exercises incorporate one of the fundamental principles in kinetic chain rehabilitation: facilitating distal motion by initially activating the proximal musculature.51,52 Proximal activation of leg and trunk musculature before activating primary movers in to prepare the entire system for motion is called anticipatory postural adjustment.12,13 We emphasize trunk and leg motion to use this natural motor control pattern and to be sure the trunk is properly positioned to allow arm motion.

Flexibility of the surrounding shoulder musculature and spine is addressed early in the rehabilitation program in association with strengthening exercises. Stretching exer-cises such as corner stretch, scapular retraction on a roll, and biceps stretch (Fig. 50-7) are used to lengthen tight pectoral musculature, which has been demonstrated to negatively affect scapular kinematics.36 Each stretch should be held for 30 seconds and performed two or three times at least once a day.53 Cervical, thoracic, and lumbar spine fl exibility exercises are prescribed to address mobility re-strictions identifi ed in the examination.

The combination of stretching and strengthening exercises has been found to positively affect posture. Wang and col-leagues54 demonstrated that a program of progressive resistive exercises using elastic resistance of horizontal ab-duction, scapular retraction with external rotation, shrugs, and shoulder abduction in the scapular plane along with corner stretching performed independently decreased tho-racic kyphosis and improved scapular stability. A similar study performing shoulder external rotation, shoulder fl ex-ion, and horizontal adduction using elastic resistance exer-cises three times a week for 3 sets of 10 to 15 repetitions in combination with passively lengthening pectoralis minor and major musculature reduced forward scapular displace-ment by almost 1 cm in young competitive swimmers.35

Unfortunately, not all patients respond to stretching and strengthening exercises. In some chronic pain conditions, patients cannot correct their own posture and need exter-nal assistance. In the past, fi gure-of-eight clavicle straps and other braces reminding patients of their posture have been used. McConnell taping to either facilitate or inhibit scapular musculature might decrease pain and improve function.55-57 Scapular taping is typically applied to retract, posteriorly tilt, and externally rotate the scapula (Fig. 50-8) to allow the patient to perform functional activities with less pain.55 The tape is applied and left on for several days at a time until the patient demonstrates adequate neuro-muscular control of the scapula independent of the tape.

One drawback of taping is that the patient requires the assistance of another to apply the tape. Therefore, the pa-tient has to return to the clinic frequently or have another person trained to tape the scapula. Another drawback is that the tape is expensive and occasionally can irritate the patient’s skin. The spine and scapula stabilizing brace (Scapula Stabilizing System [S3], Alignmed, Santa Ana, Calif) corrects postural alignment of the scapular and spine by simulating the effects of taping (Fig. 50-9). The

Figure 50-6. Low row.

Figure 50-7. Biceps stretch to stretch the anterior shoulder musculature attaching to the scapula. It is critical that the scapula stays retracted and no neurologic symptoms are present during the maneuver.



initial results of the brace on scapular kinematics suggest that the brace alters scapular posterior tilt and scapular external rotation in the lower ranges of arm elevation. Anecdotal reports from our patients with scapular dyski-nesis are mixed; however, some patients do have good relief of symptoms from this orthosis. Further research is necessary to determine its effectiveness.

Proximal StabilityProximal leg, trunk, and scapular musculature is activated to prepare the system for higher demanding distal loads. The proximal-to-distal muscle activation pattern is a normal motor-activation pattern for upper-extremity motions.12,14 To promote a functional rehabilitation approach, we at-tempt to recreate this activation approach. A common mis-take in treating shoulder injuries is the early use of exercises

that incorporate the entire length of the arm with resistance applied distally. The load of arm alone is approximately 5% of a person’s body weight.58 The often-infl amed structures about the shoulder are further aggravated when exercises that use even the weight of the arm alone are initiated. We attempt to reduce this occurrence in three ways: Strengthen proximal muscles fi rst to avoid infl aming healing tissues further, use the proximal muscles to assist in moving the distal extremity through momentum, and support the weight of the upper arm by keeping it in contact with a surface during large arcs of motion initially until proper mechanics and neuromuscular control of the motion are demonstrated.

Trunk strength and stability are initially screened during the examination with the single leg stance and squat. In patients demonstrating poor stability, specifi c strength tests are performed on hip musculature to identify specifi c strength defi cits. The hip defi cits are incorporated with the core stabi-lization exercise program, focusing on activating transverse abdominus and multifi dus muscles by performing a drawing in maneuver. Activation of these muscles always precedes distal arm motion.13,59 In patients with signifi cant core stabi-lization defi cits, a basic mat program should be initiated, progressing to functional motions. An ideal period to focus on core stabilization exercises is in the immobilization period following a shoulder surgery or signifi cant injury, when shoulder activities are limited. The core stabilization program can be emphasized on alternating days to break up the redundancy of a rehabilitation program in an athletic envi-ronment when patients are seen frequently.

Kinetic chain shoulder exercises attempt to use the trunk and legs to gain control of the trunk and facilitate scapula and shoulder motion. Knott and Voss call this irradiation, a process of facilitating inhibited muscle by activating stron-ger muscles that are synergistic for a movement pattern.60 We focus on facilitating scapular retraction (external rota-tion, posterior tilt, depression) as our primary goal to gain proximal stability for the shoulder. The treating clinician needs to have several methods to facilitate this control and progressively increase the demands to strengthen the periscapular musculature. Use of sagittal trunk motion, by starting with trunk fl exed and moving into extension, to facilitate scapular retraction is a fi rst-line activity. Integrat-ing horizontal rotation or frontal plane motions can be in-corporated to provide variety or if sagittal motions do not produce the desired scapular retraction with correct trunk posture. Incorporating a 4- to 6-inch step into an exercise engages the lower extremity and trunk musculature invol-untarily. This additional demand recruits a greater neuro-motor pool of the proximal musculature to assist stabiliza-tion and requires patients to work on postural stability by challenging their balance.

The individual needs of the patient, the fundamental principles of physiologic healing tissue restrictions, and

Figure 50-8. Scapular taping to retract the scapula during scaption exercise.

Figure 50-9. Spine and scapula stabilizing brace from a posterior view with all support strapping applied.



progressing from low- to high-demand activities are always respected during the course of rehabilitation. Examples of scapular retraction exercises are provided in attempt to meet the goals outlined earlier (Box 50-2 and Figs. 50-10 to 50-13) Typically, the patient can control the scapula with these inte-grative techniques; however, some patients require manual assistive and resistive techniques described as rhythmic ini-tiation and reversal of antagonists.60 These techniques can be performed with the patient side lying, if necessary, to isolate scapular muscle control as described by Adler,61 or they can be performed standing, applying resistance to the scapula through the motion.

Overhead Elevation ProgressionArm elevation progression can begin when a patient demonstrates adequate scapular stability with retraction. It is not expected that the athlete will go through an entire

BOX 50-2. Scapular Retraction Exercises

Isometric ExercisesIsometric exercises are used for patients to activate scapular retractors in a controlled environment requiring minimal to no glenohumeral motion.

LOW ROW (SEE FIG. 50-6)

The low row produces scapular retraction and depres-sion. With the hand at the side, extension of the shoulder is coordinated with a forward weight shift to the opposite leg. This can be performed isometrically and progressed to an isotonic exercise. Be certain the lower trapezius is activated and the scapula is depressing.

INFERIOR GLIDE (SEE FIG. 50-10)

The inferior glide produces scapular retraction with shoul-der adduction with the arm abducted to approximately 90 degrees. Be certain the lower trapezius is activated and the scapula is depressing.

Dynamic Standing ExercisesDynamic standing exercise is the most common. The pa-tient takes an astride athletic position to perform these exercises with the opposite side leg slightly forward.

LAWNMOWER (IN SLING)

The patient starts with the trunk fl exed and rotated slightly toward the opposite leg. The scapula is retracted and the arm is supported in a sling. The motion is the same as in the standard lawnmower exercise but with small ampli-tude and low intensity.

LAWNMOWER SUPPORTED (SEE FIG. 50-11)

The patient strives for the same scapular retraction end position, but the arm is free to move and the weight of the arm is supported so as not to overload infl amed tissues in the glenohumeral joint.

LAWNMOWER ON A STEP (SEE FIG. 50-12)

The patient starts with the trunk fl exed and rotated trunk the opposite leg. The scapula is retracted with the arm

externally rotating. The addition of the step is to facilitate more trunk and pelvic muscle activation to encourage bet-ter scapular retraction during the maneuver.

SHOULDER DUMP

The patient starts with the trunk fl exed and rotated toward the opposite leg just as in the lawnmower exercises. The scapula is retracted with the arm abducting and externally rotating within a pain-free range. This activity simulates the cocking phase of a throwing motion.

Dynamic Sitting ExercisesDynamic sitting exercises are for patients who have lower-extremity limitations that preclude them from dynamic standing activities or who need to perform a signifi cant component of their sports in a nonstanding phase such as swimming, water polo, and volleyball. Dynamic sitting ac-tivities can be started on a stable chair and progressed to a Swiss ball or a wobble board for home therapy. The pa-tient is progressed to place the feet on the unstable sur-face to increase trunk demand.

SCAPULAR RETRACTION ON BALL (SEE FIG. 50-13)

The lawnmower exercise is performed in a sitting position to facilitate scapular retraction with greater emphasis placed on trunk and scapular musculature, because the legs cannot contribute as much. The patient sits on a Swiss ball and reaches with the affected arm down toward the weight-bearing ankle. The patient retracts and depresses the scapula while pulling the elbow toward the back pocket and shifting the weight toward the opposite leg.

DIAGONAL ROTATIONS ON BALL

Perform a diagonal resistance pattern while sitting on a ball. This exercise simulates throwing activities such as arm cocking, pulling arm into abduction, and external rotating and it simulates the acceleration phase of throwing, bring-ing the arm from overhead diagonally across the body.

Figure 50-10. Inferior glide with the scapula posteriorly tilting due to activation of the lower trapezius muscle.



A B

Figure 50-11. Lawnmower exercise, supported, allows the patient to start moving through the functional range of motion but does not overload healing tissues by keeping the weight of the arm supported on the Swiss ball. A, Starting position, to be adjusted to limits of comfort and motion restrictions. B, Ending position to emphasize scapular retraction.

BA

Figure 50-12. Lawnmower exercise on a step to facilitate core muscle activation. A, Starting position to prestretch target musculature, B, Finishing position incorporates lower extremity stability with trunk and scapular retraction in a single exercise.



A B

Figure 50-13. Scapular retraction on a Swiss ball. A, Start by reaching toward the ipsilateral leg with weight on the ipsilateral foot and the contralateral foot slightly off the ground. B, Finish by retracting the scapula and tucking elbow into the back pocket as weight is shifted off the ipsilateral foot onto the contralateral foot.

A B

Figure 50-14. Kinetic chain wall slides. Overhead reach with towel slide starting in crouched position (A) and using the legs to drive the arm up while simultaneously reaching overhead (B).



retraction program before initiating elevation exercises. However, it is a common rehabilitation error that patients are given elevation exercises that are too demanding, which result in scapular substitutions and infl amed shoulder tissues. The primary aim during this progression is to gain the pain-free and substitution-free full active arm elevation unsupported. Once this is obtained, more-demanding strengthening programs are initiated, leading to task- and sport-specifi c activities.

The initial arm elevation exercises should be performed with the arm supported and initiated by the trunk and legs. Support of the arm can be easily obtained by sliding the hand along a surface. Lephart described this type of motion as a “movable boundary with axial load.”62 The friction be-tween these two surfaces should be minimized to allow the patient to move the arm freely. This can be obtained by using a towel on a glass or smooth wooden door or using lotion or powder on a treatment plinth. The arm load is diminished

TABLE 50-1 Exercise Progression for Shoulder Musculature

Exercise Deltoid Supraspinatus Upper Trapezius Serratus Anterior Lower Trapezius

Rows with elastic tubing1,2 NA

Peak: 39 ± 16Avg: 9 ± 2

Peak: 34 ± 23Avg: 9 ± 6

Peak: 10 ± 6Avg: 5 ± 4 NA

Unilateral rows3,4 72 ± 20 NA 63 ± 17 14 ± 6 45 ± 17

Standing press-up with elbow bent 5

30 ± 11 30 ± 17 24 ± 8 29 ± 13 9 ± 5

Forward punch2 Peak: 39 ± 23Avg: 9 ± 4

Peak: 48 ± 83Avg: 8 ± 3

NA Peak: 49 ± 14Avg: 10 ± 3

NA

Prone fl exion at 135 deg of abduction3

NA NA 79 ± 18 43 ± 17 97 ± 16

Prone ER at 90 deg3,6

NA 50 20 ± 18 57 ± 22 79 ± 21

Unilateral shoulder press supine w/a plus3

N.A NA 7± 3 62 ± 19 11 ± 5

Scaption �80 deg3,7 91 ± 26 82 ± 27 72 ± 19 62 ± 18 50 ± 21

Military press4,8 72 ± 24 56 ± 48 64 ± 26 82 ± 36 NA

Scaption �120 deg3,4

72 ± 13 64 ± 28 79 ± 19 96 ± 24 61 ± 19

Diagonal fl exion, horizontal adduction, ER3

NA NA 66 ± 10 100 ± 24 39 ± 15

Push-up with a plus9 NA NA 50 140 30

Note: This exercise progression for shoulder musculature is based on published EMG literature and is organized based on the serratus anterior musculature. The percentage of the maximal voluntary isometric contraction plus or minus standard deviation is that reported in the cited reference. Caution should be used in interpreting this table because different loads were used in different studies, which can account for EMG variations.1. Decker MJ, Hintermeister RA, Faber KJ, et al: Serratus anterior muscle activity during selected rehabilitation exercises. Am J Sports Med 27:784-791, 1999.2. Hintermeister RA, Lange G, Schultheis J, et al: Electromyographic activity and applied load during shoulder rehabilitation exercises using elastic resistance. Am J Sports Med 26:210-220, 1998.3. Ekstrom RA, Donatelli RA, Soderberg G: Surface electromyographic analysis of exercises for the trapezius and serratus anterior muscles. J Orthop Sports Phys Ther 33:247-258, 2003.4. Townsend H, Jobe FW, Pink M, et al: Electromyographic analysis of the glenohumeral muscles during a baseball rehabilitation program. Am J Sports Med 19:264-272, 1991.5. Lawson L, Klare K, Uhl TL: Electromyographic assessment of 13 shoulder rehabilitation exercises. Unpublished data, 2003.6. Blackburn TA, McLeod WD, White B, et al: EMG analysis of posterior rotator cuff exercises. J Athl Train 25:40-45, 1990.7. Alpert SW, Pink MM, Jobe FW, et al: Electromyographic analysis of deltoid and rotator cuff function under varying loads and speeds. J Shoulder Elbow Surg 9:47-57, 2000. 8. Moseley JB, Jobe FW, Pink M, et al: EMG analysis of the scapular muscles during a shoulder rehabilitation program. Am J Sports Med 20:128-134, 1992.9. Lear JL, Gross MT: An electromyographical analysis of the scapular stabilizing synergists during a push-up progression. J Orthop Sports Phys Ther 28:146-157, 1998.avg, average EMG amplitude occurring during the exercise by a particular muscle; EMG, electromyography; ER, external rotation; NA, not available; peak, peak EMG amplitude reached during exercise performed by a particular muscle.



and the demand is lessened on shoulder musculature by placing the hand in contact with a surface.63 Progressing from horizontal limited fl exion angle (� 60 degrees) to a vertical surface allowing full fl exion is a logical progression. However, in arm-elevation exercises that are near 90 de-grees, the load of the arm is the greatest and increases the demand on shoulder musculature.63,64 In some cases, pa-tients tolerate vertical motions before they tolerate more di-agonal reaching motions that place the arm at 90 degrees. These arm elevation motions are initiated by placing the patient in the astride athletic position, with the hips and knees fl exed, and instructing the patient to drive the arm up by extending the lower legs and continuing the reaching task through the upper extremity (Fig. 50-14). This allows momentum to be used. As strength of the shoulder in-creases, less use of trunk motion is encouraged to decrease the use of momentum. Removal of the support surface makes the exercise a more-functional open-kinetic-chain strengthening exercises.

Strengthening ProgressionPatients can progress to traditional long-lever-arm resis-tance exercises to strengthen and gain endurance once they demonstrate proper control of shoulder and scapular motion during both retracting and overhead reaching activities. The patient should be able to elevate at least to 120 degrees without resistance without scapular winging or shrugging (dyskinesis). The exercises described to this point have focused on gaining neuromuscular control of the scapula through using the kinetic chain. Incorporating resistive exercises that have been found to activate shoul-der and scapular musculature by electromyographical (EMG) studies is important. The challenge of increasing load, repetitions, and speed are all factors that should be incorporated into the recovery and sport-specifi c phases of rehabilitation after a solid base of the spine and scapula are established.

EMG studies have focused on identifying which exercise maximally activates the scapular musculature. In 1992, Moseley65 published core exercises to maximally activate the trapezius, serratus anterior, and rhomboids. Other research-ers have investigated other shoulder exercises to help de-velop an exercise progression for clinicians to strengthen scapular and shoulder musculature.44,66-68 One major under-lying principle of rehabilitation is to progress from lower-demand to higher-demand activities without overloading healing tissues. This guiding principle in rehabilitation has led us to develop a scapular strengthening exercise progres-sion based on the available literature. The exercise progres-sion starts from the point of the patient demonstrating controlled active forward elevation without scapular substi-tutions and pain (Table 50-1). The exercise order is changed depending on the target musculature; for this table we tar-geted the serratus anterior.

References

1. Feltner ME, Dapena J: Three-dimensional interactions in a two-segment kinetic chain. Part I: General model. Int J Sport Biomech 5:403-419, 1989.

2. Putnam CA: Sequential motions of body segments in strik-ing and throwing skills: Description and explanations. J Biomech 26:125-135, 1993.

3. Hirashima M, Kadota H, Sakurai S: Sequential muscle activity and its function role in the upper extremity and trunk during overarm throwing. J Sports Sci 20:301-310, 2002.

4. Fleisig GS, Barrentine SW, Escamilla RF, et al: Biomechanics of overhand throwing with implications for injuries. Sports Med 21:421-437, 1996.

5. Toyoshima S, Hoshikawa T, Miyashita M: Contributions of Body Parts to Throwing Performance. Biomechanics IV. Baltimore, University Park Press, 1974, pp 169-174.

6. Kibler WB. Biomechanical analysis of the shoulder during tennis activities. Clin Sports Med 14:79-85, 1996.

7. Davids K, Glazier P, Arajuo D, et al: Movement systems as dynamic systems: The functional role of variability and its implications for sports medicine. Sports Med 33:245-260, 2003.

8. Kraemer WJ, Triplett NT, Fry AC: An in-depth sports medi-cine profi le of women college tennis players. J Sport Rehabil 4:79-88, 1995.

9. Inman VT, Saunders M, Abbott LC: Observations of the func-tion of the shoulder joint. J Bone Joint Surg Am 26:1-31, 1944.

10. Perry J: Anatomy and biomechanics of the shoulder in throwing, swimming, gymnastics, and tennis. Clin Sports Med 2:247-270, 1983.

11. Davidson PA, El Attrache NS, Jobe CM et al: Rotator cuff and posterior-superior glenoid labrum injury associated with increased glenohumeral motion: A new site of impingement. J Shoulder Elbow Surg 4:384-390, 1995.

12. Zattara M, Bouisset S: Posturo-kinetic organisation during the early phase of voluntary upper limb movement. 1 Normal subjects. J Neurol Neurosurg Psychiatry 51:956-965, 1988.

13. Cordo PJ, Nashner LM: Properties of postural adjustments associated with rapid arm movements. J Neurophysiol 47:287-308, 1982.

SUMMARY

It is important to evaluate dynamic function of the scapula with and without load and evaluate trunk position and control during dynamic activities such as a single-leg squat. If all impairments are not identifi ed in a complete assessment, the athlete is likely to return with similar complaints. Our rehabilitation approach addresses the defi cits identifi ed in the examination with particular focus on improving trunk and scapular posture. Rehabilitation that focuses on enhancing proximal stability and control of pelvis, trunk, and scapula should establish a foundation; then, patient-specifi c exercises that gradually increase the demands of the scapular and shoulder musculature can be built on this foundation.



14. Bouisset S, Zattara M: A sequence of postural movements precedes voluntary movement. Neurosci Lett 22:263-270, 1981.

15. Le Bozec S, Lesne J, Bouisset S: A sequence of postural muscle excitation precedes and accompanies isometric ramp efforts performed while sitting in human subjects. Neurosci Lett 303:72-76, 2001.

16. Karduna AR, McClure PW, Michener LA, et al: Dynamic measurements of three-dimensional scapular kinematics: A validation study. J Biomech Eng 123:184-190, 2001.

17. McClure PW, Michener LA, Sennett BJ, et al: Direct 3-dimensional measurement of scapular kinematics during dynamic movements in vivo. J Shoulder Elbow Surg 10:269-277, 2001.

18. Warner JJP, Micheli LJ, Arslanian LE, et al: Scapulothoracic motion in normal shoulders and shoulders with glenohu-meral instability and impingement syndrome. A study using Moiré topographic analysis. Clin Orthop Rel Res (285):191-199, 1992.

19. Rubin BD, Kibler WB: Fundamental principles of shoulder rehabilitation: Conservative to postoperative management. Arthroscopy 18:29-39, 2002.

20. Schultz JS, Leonard A Jr: Long thoracic neuropathy from athletic activity. Arch Phys Med Rehabil 73:87-90, 1992.

21. Warner JJ, Navarro RA: Serratus anterior dysfunction. Recognition and treatment. Clin Orthop Rel Res (349):139-148, 1998.

22. Cools AM, Witvrouw E, Declercq GA et al: Evaluation of isokinetic force production and associated muscle activity in the scapular rotators during a protraction-retraction movement in overhead athletes with impingement symptoms. Br J Sports Med 38:64-68, 2004.

23. Borstad JD, Ludewig PM: The effect of pectoralis minor length on scapular kinematics in subjects without shoulder pathol-ogy [abstract]. J Orthop Sports Phys Ther 34(1):A16, 2004.

24. McQuade KJ, Dawson JD, Smidt GL: Scapulothoracic mus-cle fatigue associated with alterations in scapulohumeral rhythm kinematics during maximum resistive shoulder elevation. J Orthop Sports Phys Ther 28:74-80, 1998.

25. Tsai L, Wredmark T, Johansson C, et al: Shoulder function in patients with unoperated anterior shoulder instability. Am J Sports Med 19:469-473, 1991.

26. Brox JI, Roe C, Saugen E, et al: Isometric abduction muscle activation in patients with rotator tendinosis of the shoul-der. Arch Phys Med Rehabil 78(11):1260-1267, 1997.

27. Scovazzo ML, Browne A, Pink M, et al: The painful shoulder during freestyle swimming, an electromyographic cinemat-ographic analysis of twelve muscles. Am J Sports Med 19:577-582, 1991.

28. Wadsworth DJ, Bullock-Saxton JE: Recruitment patterns of the scapular rotator muscles in freestyle swimmers with subacromial impingement. Int J Sports Med 18:618-624, 1997.

29. Glousman R, Jobe FW, Tibone JE, et al: Dynamic electro-myographic analysis of the throwing shoulder with gleno-humeral instability. J Bone Joint Surg Am 70:220-226, 1988.

30. Ludewig PM, Cook TM: Alterations in shoulder kinematics and associated muscle activity in people with symptoms of shoulder impingement. Phys Ther 80:276-291, 2000.

31. Lukasiewicz AC, McClure P, Michener L, et al: Comparison of 3-dimensional scapular position and orientation between

subjects with and without shoulder impingement. J Orthop Sports Phys Ther 29:574-586, 1999.

32. Burkhart SS, Morgan CD, Kibler WB: The disabled throwing shoulder: Spectrum of pathology. Part I: Pathoanatomy and biomechanics. Arthroscopy 19:404-420, 2003.

33. Kamkar A, Irrgang JJ, Whitney SL: Nonoperative manage-ment of secondary shoulder impingement syndrome. J Orthop Sports Phys Ther 17:212-224, 1993.

34. Kebaetse M, McClure P, Pratt N: Thoracic position effect on shoulder range of motion, strength, and three-dimensional scapular kinetics. Arch Phys Med Rehabil 80:945-950, 1999.

35. Kluemper M, Uhl TL, Hazelrigg H: Effect of stretching and strengthening shoulder muscles on forward shoulder posture in competitive swimmers. J Sport Rehabil 15:58-70, 2006.

36. Borstad JD, Ludewig PM: The effect of long versus short pectoralis minor resting length on scapular kinematics in healthy individuals. J Orthop Sports Phys Ther 35:227-238, 2005.

37. Kibler WB: Role of the scapula in the overhead throwing motion. Contemp Orthop 22:525-532, 1991.

38. Odom CJ, Taylor AB, Hurd CE, et al: Measurement of scap-ular asymmetry and assessment of shoulder dysfunction using the lateral scapular slide test: A reliability and validity study. Phys Ther 81:799-809, 2001.

39. Kibler WB, Uhl TL, Maddux JQ, et al: Qualitative clinical evaluation of scapular dysfunction. A reliability study. J Shoulder Elbow Surg 11:550-556, 2002.

40. Kibler WB, McMullen J: Scapular dyskinesis and its relation to shoulder pain. J Am Acad Orthop Surg 11:142-151, 2003.

41. DiMattia MA, Livengood AL, Uhl TL, et al: What are the validity of the single-leg squat test and its relationship to hip abduction strength. J Sport Rehab 14:108-123, 2005.

42. Michener LA, Boardman ND, Pidcoe PE, et al: Scapula muscle tests in subjects with shoulder pain and functional loss: reliability and construct validity. Phys Ther 85:1128-1138, 2005.

43. Kendall FP, McCreary EK, Provance PG: Upper extremity and shoulder girdle strength test. In Butler JP (ed): Muscle Testing and Function. Baltimore, Williams & Wilkins, 1993, pp 235-298.

44. Ekstrom RA, Donatelli RA, Soderberg G: Surface electro-myographic analysis of exercises for the trapezius and serra-tus anterior muscles. J Orthop Sports Phys Ther 33:247-258, 2003.

45. Smith J, Padgett DJ, Kaufman KR, et al: Rhomboid muscle electromyography activity during 3 different manual muscle tests. Arch Phys Med Rehab 85:987-992, 2004.

46. Kibler WB, Sciascia A, Dome D: Evaluation of apparent and absolute supraspinatus strength in patients with shoulder injury using the scapular retraction test. Am J Sports Med 34:1643-1647, 2006.

47. Kibler WB, Livingston B, Bruce R: Current concepts in shoulder rehabilitation. Adv Oper Orthop 3:249-299, 1995.

48. Kapandji IA: The shoulder. In Kapandji IA (ed): The Physi-ology of the Joints. New York, Churchill Livingstone, 1982, pp 2-71.

49. Solem-Bertoft E, Thuomas KA, Westerberg CE: The infl u-ence of scapular retraction and protraction on the width of the subacromial space. An MRI study. Clin Orthop Relat Res (296):99-103, 1993.



50. Smith J, Kotajarvi BR, Padgett DJ, Eischen JJ: Effect of scap-ular protraction and retraction on isometric shoulder eleva-tion strength [abstract]. Arch Phys Med Rehab 83:367-370, 2002.

51. McMullen J, Uhl TL: A kinetic chain approach for shoulder rehabilitation. J Athl Train 35:329-337, 2000.

52. Kibler WB, McMullen J, Uhl T: Shoulder rehabilitation strategies, guidelines, and practice. Orthop Clin North Am 32:527-538, 2001.

53. Bandy WD, Irion JM, Briggler M: The effect of time and frequency of static stretching on fl exibility of the hamstring muscles. Phys Ther 77:1090-1096, 1997.

54. Wang C-H, McClure P, Pratt N et al: Stretching and strengthening exercises: Their effect on three-dimensional scapular kinematics. Arch Phys Med Rehabil 80:923-929, 1999.

55. Host HH: Scapular taping in the treatment of anterior shoulder impingement. Phys Ther 75:803-811, 1995.

56. Cools AM, Witvrouw EE, Danneels LA, et al: Does taping infl uence electromyographic muscle activity in the scapular rotators in healthy shoulders? Man Ther 7:154-162, 2002.

57. Ackermann B, Adams R, Marshall E: The effect of scapula taping on electromyographic activity and musical perfor-mance in professional violinists. Aust J Physiother 48:197-203, 2002.

58. Dempster WT: Space requirements of the seated operator: Geometrical, kinematic, and mechanical aspects of the body, with special reference to the limbs. Technical Report TR-55-159. Wright-Patterson Air Force Base, Ohio, 1955.

59. Hodges PW, Richardson CA: Feedforward contraction of transversus abdominus is not infl uenced by the direction of arm movement. Exp Brain Res 114:362-370, 1997.

60. Knott M, Voss DE: Proprioceptive Neuromuscular Facilitation Patterns and Techniques. Philadelphia, Harper & Row, 1968.

61. Adler SS, Beckers D, Buck M: PNF in Practice: An Illustrated Guide. New York, Springer-Verlag, 1993.

62. Lephart SM, Henry TJ: The physiological basis for open and closed kinetic chain rehabilitation for the upper extremity. J Sport Rehabil 5:71-87, 1996.

63. Wise MB, Uhl TL, Mattacola CG, et al: The effect of limb support on muscle activation during shoulder exercises. J Shoulder Elbow Surg 13:614-620, 2004.

64. Poppen N, Walker P: Forces at the glenohumeral joint in abduction. Clin Orthop Rel Res (135):165-170, 1978.

65. Moseley JB, Jobe FW, Pink M, et al: EMG analysis of the scapular muscles during a shoulder rehabilitation program. Am J Sports Med 20:128-134, 1992.

66. Decker MJ, Hintermeister RA, Faber KJ, et al: Serratus anterior muscle activity during selected rehabilitation exer-cises. Am J Sports Med 27:784-791, 1999.

67. Decker MJ, Tokish JM, Ellis HB, et al: Subscapularis muscle activity during selected rehabilitation exercises. Am J Sports Med 31:126-134, 2003.

68. Ekstrom RA, Bifulco KM, Lopau CJ, et al: Comparing the function of the upper and lower parts of the serratus anterior muscle using surface electromyography. J Orthop Sports Phys Ther 34:235-243, 2004.


the athlete's shoulder || the role of the scapula in rehabilitation

Documents