The Effects of PNF Stretching on Hamstring Flexibility in

Female Collegiate Soccer and Volleyball Players

By: Kristina Everding, Emily Lensing, Shannon Ditsch, and Danielle Vujovic

Introduction

Hamstring flexibility in female soccer and volleyball players

Benefits in PNF stretching Volleyball players more flexible

Introduction Cont.

Three large muscle groups:

Introduction Cont.

Tested three types of PNF stretching: Hold and Relax Contract and Relax Relax with opposing muscle contraction

PNF relies on neuromuscular characteristics in order to relax the muscles

Improve flexibility by inhibiting muscle contraction

Introduction Cont.

Studies are very contradictory More research needed

Participants

24 total NCAA Division III female athletes

12 soccer players 12 volleyball players All were between the ages of 18-23 No current hamstring injuries Participants for each team had

similar fitness levels

Measures, Instruments, Tasks V Sit and Reach Box

Used to measure flexibility of lower back and hamstrings

Measures, Instruments, Tasks V Sit and Reach Test Protocol

Sitting on the ground Legs straight out in front with knees flat

to the ground with no shoes on Feet are pressed against the V Sit and

Reach Box Participant will reach with both hand and

push the knob as far as they can They did they 3 times and took their

best score

Measures, Instruments, Tasks Proprioceptive Neuromuscular

Facilitation (PNF) Hold-Relax Contract-Relax Relax with opposing muscle contraction

Procedure

6 different trial days (nonconsecutive)

On days of normal practice/workouts Took place in AWC for volleyball Took place in Rockbowl for soccer Trials were conducted immediately

after practice

Procedure

Half of the trial were followed by PNF stretching (2,4,6)

Other half was without PNF stretching (1,3,5)

On the stretching days, we split up the participants to ensure more accurate results Stay warm and loose

Results

Mean scores were found for each participant

A Dependent Samples T-test was conducted Non- stretching mean: M=35.84 cm PNF stretching mean: M=37.35 cm There was a significant difference▪ P value: 0.001 and T value: -3.916

Dependent Samples T-Test  Mean Standard

DeviationDegrees of Freedom

T-value P-value

No Stretching 35.8403 9.9618   

23

 -3.916

 .001

PNF Stretching 37.3472 9.35930

No Stretching PNF Stretching35

35.5

36

36.5

37

37.5

The Effects of PNF Stretching on Hamstring Flexibility in Female Collegiate Soccer and Volleyball Players

Stretching Mode

Sit and Reach Scores (cm)

Results

Two Independent Sample T-tests were conducted Test 1: to determine if significant

difference in scores before PNF stretching▪ Mean score for soccer players: M= 36.97cm▪ Mean score for volleyball players: M=34.71cm▪ Significant difference not was found

(P=0.473, t=.548)

Independent Samples T-Test (no stretching)  Mean Standard

DeviationDegrees of Freedom

T-value P-value

Soccer 36.9722 8.991 22  .548

 .473

Volleyball 34.7083 11.130

Results

Test 2: to determine if difference in scores after PNF stretching▪ Mean score for soccer players: M=38.53cm▪ Mean score for volleyball players: M=36.12cm▪ Significant difference was not found

(p=0.400, t=.609)

Independent Samples T-Test (PNF stretching)  Mean Standard

DeviationDegrees of Freedom

T-value P-value

Soccer 38.5278 2.534 22  .609

 .400

Volleyball 36.1667 2.930

Conclusion Accept hypothesis 1-PNF stretching increased ROM

This agrees with Silva et al. (2012), as they found that PNF stretching promotes a greater range of motion.

Conclusion Cont. Reject hypothesis 2-Female soccer players had higher V Sit and Reach results than volleyball players. However, this difference was not significant.

Extraneous Variables Weather conditions Intensity levels Efficiency of data collection Soreness of athlete

Future Studies Longer study duration More participants Smaller test administrator to

participant ratio Male study

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