Ascending Stairs: Task Related Determinants

Ascending Stairs: Task Related DeterminantsBy: Jessie Brown and Chelsea Zemmin

Cycle Defined By:Initiation:Toe off of first stepTermination:Ipsilateral foot toe off of second step

(Looking at the R leg)

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StabilityCoordinationForce ProductionAlignment

SpeedCenter of MassBase of SupportControl Maintenance Foot placementTransition Symmetry Body positionBalanceOur ProcessLE Force ProductionDynamic Postural StabilityLE CoordinationAlignmentRange of Motion

Force ProductionContraction of muscles that allow the center of mass to be moved over the base of support in a superior and anterior direction

Most important muscles needed for the production of force that allows execution of task:QuadricepsHip ExtensorsAnkle Dorsiflexors

Force ProductionMcclelland et. al. Proper force production of the quadriceps is needed for proper stair accentThey measured the knee flexion and extension moments and compared control group with patients post TKA.All participants generated a knee flexion moment that changed direction to an extension moment during stair ascentPatients post TKA with decreased quadriceps strength reduced flexion moment and an earlier change in moment direction from flexion to to compensate for decreased quadriceps strength.

When force production of quadriceps is absent, this results in abnormal stair climb patterns and compensations.

Mcclelland et. al. determined that proper force production of the quadriceps is needed for proper stair accent. They measured the knee flexion and extension moments and compared control group with patients post TKA. All participants generated a knee flexion moment that changed direction to an extension moment during stair ascent. However, for patients post TKA who presented with decreased quadriceps strength,the moment pattern was characterised by a reduction in the magnitude of the flexion moment and a change in moment direction from flexion to extension that occurred earlier in the step cycle to compensate for decreased quadriceps strength. When force production of quadriceps is absent, this results in abnormal stair climb patterns and compensations as measured in the study by Mcclelland et. al.

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Force ProductionTiedemann et al.Linear relationship between strength of hip and knee extensors and ankle dorsiflexors and speedGender and age correlation with strength

Age 75-98 community dwelling adults8 stairs. Allowed to use the hand rail and gait aid if they desiredGender difference : 4.8 +/- 2.2 men ; 6.0 +/- 3.4 womenModerate correlated with age 6

Dynamic Postural StabilitySingle limb stancePostural Stability: maintenance of center of mass within the base of supportPostural OrientationMotor ControlPostural OrientationPostural Stability

Postural Orientation7

Dynamic Postural StabilityAnterior-Posterior AxisMaintain COM within BOS, lateral directionButler et al.Hand rail use52% older adults

50 participants 20-39yrs684 participants 75-98yrsOnly one of the younger participants used the rail while ascending the stairs while 52% of the older adult population used the rail. This instability could be the result of sensorimotor deficits that come with age. It could also be secondary to a lack of strength causing the instability. Regardless of the source, this supports the fact that stability in the A/P axis is required in order to ascend stairs.8

Dynamic Postural StabilityGeneral Postural StabilityProprioception and sensory information

Hurley, M.V. et al.Combination of proprioception, strength and integration of sensory information

Hurley MV et al found that the increase in time it takes older patients to ascend a flight is due not only to strength but also to proprioception and sensory information which together make up postural stability. All of these things add together to decrease confidence which cause longer times for older people when going up a flight of stairs. Since these factors affected stair ascention times, we can conclude that postural stability, which includes sensory and proprioception information are required to ascend stairs. When these factors are impaired, the person has difficulty and takes longer to go up the stairs.9

LE CoordinationSimultaneous hip and knee movementAdvances the center of mass over the base of support

During ascending and forward motion of the body from one step to the next step, hip extension and knee extension during the execution phase of the task occur simultaneously to allow for advancement of center of mass. 10

LE CoordinationLin et al. Stance phaseGreater required peak moments at the knee and ankle joints (first half)Hip extension moment present throughout the entire stance phase.

This coordination of simultaneous hip and knee extension is critical in transferring momentum of body up the stair.

In a study by Lin et al. Stair required greater peak moments at the knee and ankle joints in the first half of the stance phase. During stair ascent a hip extension moment was present throughout the stance phase. This coordination of hip and knee extension simultaneously is critical in transferring momentum of body up the stair.11

LE Coordination

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AlignmentPosition of adjacent body segments in relation to each otherStairs:TorsoHipKneeAnkle

AlignmentSaari et. al. Patients with knee osteoarthritis patients with knee OA also had knee instability. Joint laxity and excessive motion leads to instability during dynamic and functional activities such as stair climbing. Inability to control motion in the sagittal plane during stair accent and difficulty completing the task of stair climbing correctly.

In a study by Saari et. al. looking at patients with knee osteoarthritis patients with knee OA also had knee instability. Joint laxity and excessive motion leads to instability during dynamic and functional activities such as stair climbing. People with knee instability will not be able to control the motion in the sagittal plane during stair accent and have difficulty completing the task correctly.14

AlignmentPosition of the foot in relation to the stair surface

Foot placement on the step is also important factor to allow for proper alignment during stair accent. The placement of the entire foot on the step is important for allowing for the ankle, knee and hip to align above in to support the COM over the narrow BOS.15

Range of MotionHipExtension to Flexion: 1-0-66KneeFlexion: 93-105Extension: 0 (ideally)AnkleDF to PF: 20-0-30

Protopapadaki et al. looked at the kinematics of stair ascention and descention in young healthy adults. The maximal ranges stated here occurred during the swing phase of stair climbing. The necessary range of motion varies greatly but the study concluded that large ranges of ankle motion were not as important when compared to knee and hip ranges.16

Range of MotionKneeMean flexion: 83-105Dependent on height of person and stair

The data was collected for a stair height of 18cm and a tread length of 28.5cm which is important because the stair height can change the necessary angles produced by the body. The maximal knee flexion occurs during swing phase which is represented here as the section after 60%. This is necessary in order to clear the previous step and to place the foot on the next step.17

Range of MotionHipTorque angle profiles of the hip extensor muscles

The majority of the hip range of motion is in flexion, the majority of the moment is into extension. You can also see in the ROM graph that the hip does not usually need to go past neutral in order to ascend the stairs. This is different than walking where the hip needs to go into at least 10 degrees of extension to have a normal pattern.18

Conclusion LE Force ProductionDynamic Postural StabilityLE CoordinationAlignmentRange of Motion