JONATHAN BURTOFT ATTR 540: RESEARCH METHODS IN HUMAN PERFORMANCE The Effect of a Single Instructional Session on Landing Mechanics Over Time in Female Collegiate Volleyball Players

Why this topic? Females are the most at risk for non-contact ACL injuries Vauhnik R, Morrissey MC, Rutherford OM, Turk Z, Pilih IA, Perme MP Instruction in landing mechanics reduces injury rates Oñate J, Guskiewicz K, Marshall S, Giuliani C, Yu B, Garrett W. June 2005 Cowling E, Steele J, McNair P. April 2003 Little research exists on the effect of time on instruction Volleyball is a jump intensive non-contact sport

Research Purpose The purpose of this study was to determine the effect of a single instructional session over 4 weeks Procedures preview  Trial 1  Instructional Session  Trial 2  2 weeks  Trial 3  2 weeks  Trial 4

Hypotheses A statistically significant difference will exist between…  Trial 2 scores and trial 4 scores Lally, P., van Jaarsveld, C., Potts, H., and Wardle, J. UK Health Behaviore Research Center. July 2010  Trial 1 scores and trial 2 scores Oñate J, Guskiewicz K, Marshall S, Giuliani C, Yu B, Garrett W. June 2005 Cowling E, Steele J, McNair P. April 2003 No statistically significant difference will exist between…  Trial 1 scores and trial 4 scores

Limitations & Delimitations Limitations  Small sample size  Limited amount of equipment  Force plates  MRI Shultz S, Schmitz R. September 2012  Time Delimitations  Females Vauhnik R, Morrissey MC, Rutherford OM, Turk Z, Pilih IA, Perme MP  College volleyball players  Q Angle within normal limits Alan M, Elizabeth A, Robert T, et al. December 2008  Without lower extremity injury within the last 2 months  Without surgery to the lower extremity within the last 2 years Padua D, Marshall S, Boling M, Thigpen C, Garrett Jr W, Beutler A. February 2010 Onate J, Cortes N, Welch C, van Lunen B. February 2010 Oñate J, Guskiewicz K, Marshall S, Giuliani C, Yu B, Garrett W. June 2005

Participants 7 Female Collegiate Volleyball players  Without lower extremity injury within the last 2 months  Without surgery to the lower extremity within the last 2 years Padua D, Marshall S, Boling M, Thigpen C, Garrett Jr W, Beutler A. February 2010 Onate J, Cortes N, Welch C, van Lunen B. February 2010 Oñate J, Guskiewicz K, Marshall S, Giuliani C, Yu B, Garrett W. June 2005  Still participating in off season practices

Instrumentation Landing Error Scoring System (LESS)  Tool for objectively measuring landing mechanics  Two cameras used to record subjects (sagittal and frontal)  Subjects are given a score between 0 and 17  Proven validity and reliability Padua D, Marshall S, Boling M, Thigpen C, Garrett Jr W, Beutler A. February 2010 Onate J, Cortes N, Welch C, van Lunen B. February 2010 Oñate J, Guskiewicz K, Marshall S, Giuliani C, Yu B, Garrett W. June 2005

Instrumentation  30cm   ½ body height  LESS Demonstration

Instrumentation

5 Point Check sheet Milner C, Fairbrother J, Srivatsan A, Zhang S.  Landing with both feet at the same time  Landing in a neutral knee valgus/varus position  Landing with feet shoulder-width apart  Landing on forefoot and rolling toward rearfoot  Landing with optimal knee and hip flexion at initial contact to be greater than 20° and estimated to be a total of approximately 90° respectively

Instrumentation 3 Camera System  30 FPS Padua D, Marshall S, Boling M, Thigpen C, Garrett Jr W, Beutler A. February 2010 Onate J, Cortes N, Welch C, van Lunen B. February 2010 Oñate J, Guskiewicz K, Marshall S, Giuliani C, Yu B, Garrett W. June 2005  Markers placed on bony landmarks  2 sagittal views and 1 frontal view  Informed consent for video recording

Procedures IRB approval by Manchester University Subject selection Demographic Questionnaire 1 st Session  Subjects fitted with bony landmark indicators  Introduction to LESS procedure  1 st trial  Instructional/correctional session w/ video feedback  2 nd trial 2 nd Session – 2 weeks later  3 rd trial 3 rd Session – 2 weeks later  4 th trial

Statistical Analysis 4 LESS scores per participant Non-parametric Friedman’s test IBM SPSS used to run all tests P =.173, P<.05

Discussion Larger population may have helped normalize data 5 point check sheet didn’t address tibial rotation Timing of trials was an issue

Conclusion Improvement was made after instruction Improvement was varied Predicted Pattern LESS scores increased with time No significance was found between trials Hypothesis between trial 1 & 4 having no significance was correct but meaningless because of lack of significance between trial 1 & 2

Questions