Transcript Artifact 1: Kinesiology Research Project

By: Kristina Everding, Emily Lensing, Shannon Ditsch, and Danielle Vujovic
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Hamstring flexibility in female soccer and
volleyball players
Benefits in PNF stretching
Volleyball players more flexible
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Three large muscle groups:
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Tested three types of PNF stretching:
 Hold and Relax
 Contract and Relax
 Relax with opposing muscle contraction
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PNF relies on neuromuscular characteristics
in order to relax the muscles
Improve flexibility by inhibiting muscle
contraction
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Studies are very contradictory
More research needed
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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
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V Sit and Reach Box
 Used to measure flexibility of lower back and
hamstrings
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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
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Proprioceptive Neuromuscular Facilitation
(PNF)
 Hold-Relax
 Contract-Relax
 Relax with opposing muscle contraction
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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
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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
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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
No Stretching
Mean
Standard
Deviation
35.8403
9.9618
Degrees of
Freedom
23
PNF Stretching
37.3472
9.35930
T-value
P-value
-3.916
.001
The Effects of PNF Stretching on Hamstring Flexibility in Female
Collegiate Soccer and Volleyball Players
37.5
37
36.5
Sit and Reach Scores (cm)
36
35.5
35
No Stretching
PNF Stretching
Stretching Mode
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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)
Soccer
Volleyball
Mean
Standard
Deviation
Degrees of
Freedom
36.9722
8.991
22
34.7083
11.130
T-value
P-value
.548
.473
 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)
Soccer
Volleyball
Mean
Standard
Deviation
Degrees of
Freedom
38.5278
2.534
22
36.1667
2.930
T-value
P-value
.609
.400
Accept hypothesis 1
-PNF stretching increased ROM
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This agrees with Silva et al. (2012), as they
found that PNF stretching promotes a
greater range of motion.
Reject hypothesis 2
-Female soccer players had higher V Sit and
Reach results than volleyball players. However,
this difference was not significant.
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Weather conditions
Intensity levels
Efficiency of data collection
Soreness of athlete
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Longer study duration
More participants
Smaller test administrator to participant ratio
Male study
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Chow, T. Y., & Nag, G. F. (2010). Active, passive and proprioceptive neuromuscular facilitation stretching are comparable
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Clinical Rehabilitation, 24(10), 911-918.
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Silva, S. B., De Faria, E. M., Almeida, J. B., Bernardes, R. C., Valenti, V. E., Vanderlei, L. M., & De Abreu, L. (2012). Effects
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