SStt.. CCaatthheerriinnee UUnniivveerrssiittyy SSOOPPHHIIAA Doctor of Physical Therapy Research Papers Physical Therapy 4-2017 IInnflfluueennccee ooff FFaattiigguuee aanndd AAnnttiicciippaattiioonn oonn KKnneeee KKiinneemmaattiiccss aanndd KKiinneettiiccss dduurriinngg aa JJuummpp--ccuutt MMaanneeuuvveerr Sara Buermann St. Catherine University Erica Gloppen St. Catherine University Regan Kriechbaum St. Catherine University Dani Potter St. Catherine University Nicole Sheehan St. Catherine University Follow this and additional works at: https://sophia.stkate.edu/dpt_papers RReeccoommmmeennddeedd CCiittaattiioonn Buermann, Sara; Gloppen, Erica; Kriechbaum, Regan; Potter, Dani; and Sheehan, Nicole. (2017). Influence of Fatigue and Anticipation on Knee Kinematics and Kinetics during a Jump-cut Maneuver. Retrieved from Sophia, the St. Catherine University repository website: https://sophia.stkate.edu/dpt_papers/55 This Research Project is brought to you for free and open access by the Physical Therapy at SOPHIA. It has been accepted for inclusion in Doctor of Physical Therapy Research Papers by an authorized administrator of SOPHIA. For more information, please contact [email protected]. INFLUENCE OF FATIGUE AND ANTICIPATION ON KNEE KINEMATICS AND KINETICS DURING A JUMP-CUT MANEUVER by Sara Buermann Erica Gloppen Regan Kriechbaum Dani Potter Nicole Sheehan Doctor of Physical Therapy Program St. Catherine University April 1st, 2017 Research Advisor: Jaynie Bjornaraa, PT, PhD, MPH, SCS, ATR, CSCS ABSTRACT BACKGROUND AND PURPOSE: Injuries to the anterior cruciate ligament (ACL) are common among athletes, particularly females. This research aims to reconcile the anticipated and unanticipated movement pattern of jumping and cutting with fatigue for both genders. The research will compare lower extremity biomechanics of a jump-cut after a sports specific fatigue protocol, intending to examine movement patterns which may predispose the subject to ACL injury. METHODS: Twenty healthy subjects were studied (24.9±3.3yrs), including 10 females. A 3D electromagnetic system measured knee kinematics and kinetics during jump-cut tasks. The jump- cut task included anticipated (A) and unanticipated (UA) trials to both directions. For the UA trials, the subject was unaware of the cutting direction until initiation of the task. The fatigue protocol consisted of jumping, sprinting, step-ups, and agility. Subjects completed the jump-cut task again in a fatigued state. A repeated measures ANOVA was used to analyze peak and mean angles, moments and ground reaction forces (GRF), with post-hoc Tukey tests for significant findings between factors (gender, pre/post-fatigue, A/UA). RESULTS: Significant main effects were found for gender and IR/ER and ADD/ABD peak and/or mean angles, and ADD/ABD moments; pre and post-fatigue and IR/ER, EXT/FLEX, and ADD/ABD peak and/or mean angles, and ADD/ABD moments; A/UA conditions and IR/ER and ADD/ABD peak and/or mean angles. Significant interactions existed for gender and A/UA for EXT moment and for pre/post-fatigue and A/UA for EXT moment, IR moment and IR/ER angles. i CONCLUSION: Subjects demonstrated significant changes in knee kinematics and kinetics. Fatigue and A/UA states influenced knee movement patterns in variable ways, which may indicate an attempt to safely land and cut. Additionally, females demonstrated biomechanics that may increase their risk for ACL injury relative to males. Gender, fatigue, and A/UA conditions had an impact on one another and should be considered when designing sports training programs to reduce risky movement patterns. ii The undersigned certify that they have read, and recommended approval of the research project entitled… INFLUENCE OF FATIGUE AND ANTICIPATION ON KNEE KINEMATICS AND KINETICS DURING A JUMP-CUT MANEUVER Submitted by, Sara Buermann Erica Gloppen Regan Kriechbaum Dani Potter Nicole Sheehan in partial fulfillment of the requirements for the Doctor of Physical Therapy Program 4/27/2017 Primary Advisor ___________________________________ Date ______________ iii ACKNOWLEDGEMENTS We would like to ensure proper recognition and acknowledgement of the individuals whom have assisted in the completion of the research study. First, Dr. Jaynie Bjornaraa for guiding us through this challenging process. Secondly, the St. Catherine University WHIR center and staff for providing the remarkable facility and resources to conduct the study. We would also like to thank our family, friends, and DPT classmates who have been so patient with us and to many who have participated in our study. iv TABLE OF CONTENTS Chapter I: Introduction 1 Chapter II: Review of Literature 6 Chapter III: Methods 80 Chapter IV: Results 87 Chapter V: Discussion 90 Chapter VI: Conclusion 94 References 95 v 1 CHAPTER I INTRODUCTION Background The anterior cruciate ligament (ACL) is a ligament within the knee joint that attaches from the anterior-medial tibia to the posterior-lateral femoral condyle. The ACL prevents anterior tibial translation in open-chain movements and therefore posterior femoral translation in a closed-chain mechanism. Another function of the ACL is to prevent excessive tibial rotation in closed-chain mechanisms. Overall, the ACL provides approximately 90% of the stability in the knee1. ACL injury prevalence is a rising problem with sources citing estimated injuries per year at 80,000 up to 250,000 1-3. ACL injury is most prevalent in patients 15-45 years old likely associated with more active lifestyles and involvement with sports1. These injuries may result from both contact and non-contact mechanisms. Non-contact mechanisms contribute to approximately 70% of ACL injuries1,4. Treatment following ACL injuries may involve either conservative rehabilitation or surgical reconstruction. Approximately 50,000 to 100,000 ACL reconstructions are performed each year in the U.S. The cost of a single reconstructive ACL surgery has been estimated to be $17,0005. When comparing the cost of reconstruction versus conservative rehabilitation, operative repair has been shown to be more cost effective with research citing a “mean lifetime cost” of $38,121 for ACL reconstruction patients versus $88,538 for rehabilitation patients6. Regardless of post-ACL injury treatment there is an increased risk of osteoarthritis (OA) in the future, which has implications for future overall costs and management of symptoms. Re-injury rates of reconstructed ACL’s are fairly low at 2.6% re-rupture rate over 2 a mean of 2.5 years after surgery1. However, post ACLr studies have found that young athletes ranging from 15-18 years old have an increased injury rate of 22% on the contralateral leg7. Research has widely shown that there is a significant disparity between ACL prevalence in females versus males. According to the National College Athletic Association (NCAA) women playing sports are 2 to 8 times more likely to sustain an ACL injury their male peers1. Numerous studies have been conducted in an effort to examine what may be leading to the significant disparity between men and women. Research has supported the notion that the cause of disparity may be multifactorial including, anatomic/structural factors, hormonal factors, and neuromuscular and biomechanical factors. In regard to anatomic/structural factors, research has proposed that a difference between genders, including increased Q angle, pelvic width, and structural laxity of stabilizing elements in the knee noted in females, are possible sources of the disparity6. Hormonal factors, including hormonal fluctuations during the menstrual cycle may be implicated in the increased rate of ACL tears in females as the ACL itself has receptors for estrogen6. According to research, estrogen levels may play a role in ACL tears due to the negative effects of estrogen on collagen and connective tissue strength6. Many studies have found females use different neuromuscular patterns during athletic maneuvers than males, which could put them at increased risk for load placed on the ACL8-15. One well studied reason may be attributed to asymmetrical lower extremity muscular activation of the quadriceps and the hamstrings during these maneuvers. Many researchers have found that females tend to activate their quadriceps more than their hamstrings, causing an increased anterior shear force of the tibia on the femur without counter activation to slow down the shearing force8,10-11,12-13. This difference in neuromuscular activation pattern could be due to the variation of kinematics between genders, which may be contributing to an increased risk to the ligamentous structure8-13. 3 Biomechanically, numerous research studies have found that women tend to land in a more valgus position when compared to their male partners, which is a position of increased risk for the ACL16. Research has also supported the fact that women tend to land from jumps with a more extended knee2,17-18. However, a more widespread review of the literature indicates that there are relative inconsistencies in results as well as numerous theories that have arisen in regard to gender differences in lower extremity biomechanics and findings may be influenced by things such as training, experience level, and the specific task19-20. ACL Reconstruction Several researchers have shown impaired knee joint biomechanics post ACL reconstruction, regardless the type of reconstruction. It has been found that after a reconstruction, excessive tibial rotation is still occurring in high demanding activities involving anterior and rotational loading of the knee. Additionally results suggest impaired neuromuscular control of the knee regardless of regained muscular strength. The impaired biomechanics of the knee may cause a change in landing patterns leading to loading cartilage instead. As a result of the change in mechanics there is an increased risk of developing knee osteoarthritis overtime. Furthermore if a muscle imbalance is present, the risk of re-injury is increased. After reconstruction, commonly quadriceps and hamstring strength deficiencies are present. This can be due to loss of afferent reaction from the ACL to gamma motor neurons. Neuromuscular control in reference to electromechanical delay can be a factor when looking at reconstructed ACL knees as well. If there is a delay between the onset of muscle stimulation and the force produced by the contraction, it can put the knee at risk of injury. This is especially concerning for the hamstrings as they are the antagonist to quadriceps, and preventing some of the anterior shearing forces mentioned above. Players returning to sport need to prepare to participate in high intensity