1. 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

2. Introduction
Hamstring flexibility in female soccer and volleyball players
Benefits in PNF stretching
Volleyball players more flexible

3. Introduction Cont.
Three large muscle groups:

4. 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

5. Introduction Cont.
Studies are very contradictory
More research needed

6. 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

7. Measures, Instruments, Tasks
V Sit and Reach Box
Used to measure flexibility of lower back and hamstrings

8. 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

9. Measures, Instruments, Tasks
Proprioceptive Neuromuscular Facilitation (PNF)
Hold-Relax
Contract-Relax
Relax with opposing muscle contraction

10. 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

11. 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

12. 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: and T value:

13. Dependent Samples T-Test
Mean
Standard Deviation
Degrees of Freedom
T-value
P-value
No Stretching
9.9618 23
-3.916
.001
PNF Stretching

15. 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)

16. Independent Samples T-Test (no stretching)
Mean
Standard Deviation
Degrees of Freedom
T-value
P-value
Soccer
8.991 22
.548
.473
Volleyball
11.130

17. 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)

18. Independent Samples T-Test (PNF stretching)
Mean
Standard Deviation
Degrees of Freedom
T-value
P-value
Soccer
2.534 22
.609
.400
Volleyball
2.930

19. 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.
most of the other works of literature in this area have shown that PNF stretching increases flexibility
Believe vball would be higher due to their sport specific movements. Hard to verify-sample so small so not generalizable to larger population
PRACTICAL APPLICATION FOR US KNOW PNF STRETCHING HELPS

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

21. Extraneous Variables Weather conditions Intensity levels
Efficiency of data collection
Soreness of athlete
For more reliable results we feel we should conduct this experiment again in a controlled setting-comparison

22. Future Studies Longer study duration More participants
Smaller test administrator to participant ratio
Male study
Not generalizable-need larger population.
Ratio: help with efficiency

23. References
Che-Hsiu, C., Tsun-Shun, H., Huei-Ming, C., Mei-Hwa, J., & Jiu-Jenq, L. (2013). Two stretching treatments for the hamstrings: proprioceptive neuromuscular facilitation versus kinesio taping. Journal of Sport Rehabilitation, 22(1), Chow, T. Y., & Nag, G. F. (2010). Active, passive and proprioceptive neuromuscular facilitation stretching are comparable in improving the knee flexion range in people with total knee replacement: a randomized controlled trial. Clinical Rehabilitation, 24(10), Davis, D., Ashby, P.E., McCale, K.L., McQuain, J.A., & Wine, J.M. (2005). The effectiveness of 3 stretching techniques on hamstring flexibility using consistent stretching parameters. Journal of Strength & Conditioning Research, 19(1), Franco, B.L., Signorelli, G.R., Tragano, G.S., Costa, P.B., & Oliveira, C. G. (2012). Acute effects of three different stretching protocols on the wingate test performance. Journal of Sports Science & Medicine, 11(1), 1-7. Jordan, B., Korgaokar, A., Farley, R., & Caputo, J. (2012). Acute effects of static and proprioceptive neuromuscular facilitation stretching on agility performance in elite youth soccer players. International Journal of Exercise Science, 5(2), Pereira, M., & Gonçalves, M. (2012). Proprioceptive neuromuscular facilitation improves balance and knee extensors strength of older fallers. ISRN Rehabilitation, 1-7. Rubini, E., Souza, A., Mello, M., Bacurau, R., Cabral, L., & Farinatti, P. (2011). Immediate effect of static and proprioceptive neuromuscular facilitation stretching on hip adductor flexibility in female ballet dancers. Journal of Dance Medicine & Science, 15(4), Silva, S. B., De Faria, E. M., Almeida, J. B., Bernardes, R. C., Valenti, V. E., Vanderlei, L. M., & De Abreu, L. (2012). Effects of two proprioceptive neuromuscular facilitation techniques in different planes on hamstrings muscles of healthy subjects. Healthmed, 6(7),