HHP-4 Differences Observed with H:Q Ratio and ACL Injuries during Modified Agility T-test and Depth Jumps: A Pilot Study
Abstract
Extensive amounts of time and money are spent rehabilitating ligamentous injuries every year, but little research has been conducted that examines potential preventative measures. Understanding the strength topography of commonly injured joints can be used as a tool to help identify compensatory mechanisms increasing injury susceptibility. Specifically, an appropriate hamstring:quadriceps strength ratio (H:Q ratio) is one of many preventative measures that has shown promising potential in the sports medicine world. Research suggests that a H:Q ratio less than 0.80 increases risk of injury, especially ligamentous injury around the knee. Some correlation has been discovered between anterior cruciate ligament (ACL) injuries and H:Q ratio, especially in females, but more research is needed to identify the extent. Additionally, an imbalance of the H:Q ratio is commonly observed among female soccer players. Therefore, the purpose of this study is to determine whether there is a difference between H:Q ratio in athletes with previous ACL injury and those without a previous ACL injury among NCAA division II female collegiate soccer players. Upon arrival, participants will complete a health history questionnaire to determine which group participants will be placed. Surface electromyography will be used to determine muscle activity of the biceps femoris, medial hamstrings (semitendinosus and semimembranosus), rectus femoris, and vastus lateralis. Manual muscle tests will be performed to collect baseline muscle activation. Next, both participant groups will complete the modified agility T-test (MAT), and the depth jump assessment in randomized order. For the depth jumps, a 6-inch box and a 12-inch box will be used. Following three attempts, only the second jump from each height will be taken for analysis due to the Hawthorne effect. Average muscle activation during cutting and jumping events of each test will be analyzed and compared to baseline muscle activity collected during manual muscle testing. For statistical analysis, a between-subjects ANOVA will be run to analyze the differences observed between groups. Collection of data is underway. We expect to see a lower H:Q ratio during the modified agility T-test and depth jump assessments in those with previous ACL injury. A lower H:Q ratio, indicating quadriceps dominance, is expected in those with previous ACL injury due to increased susceptibility of anterior translation of the tibia facilitated by a weakened hamstring muscle group and load compromised ACL.
Keywords
ACL, H:Q Ratio, Soccer, Agility
HHP-4 Differences Observed with H:Q Ratio and ACL Injuries during Modified Agility T-test and Depth Jumps: A Pilot Study
University Readiness Center Greatroom
Extensive amounts of time and money are spent rehabilitating ligamentous injuries every year, but little research has been conducted that examines potential preventative measures. Understanding the strength topography of commonly injured joints can be used as a tool to help identify compensatory mechanisms increasing injury susceptibility. Specifically, an appropriate hamstring:quadriceps strength ratio (H:Q ratio) is one of many preventative measures that has shown promising potential in the sports medicine world. Research suggests that a H:Q ratio less than 0.80 increases risk of injury, especially ligamentous injury around the knee. Some correlation has been discovered between anterior cruciate ligament (ACL) injuries and H:Q ratio, especially in females, but more research is needed to identify the extent. Additionally, an imbalance of the H:Q ratio is commonly observed among female soccer players. Therefore, the purpose of this study is to determine whether there is a difference between H:Q ratio in athletes with previous ACL injury and those without a previous ACL injury among NCAA division II female collegiate soccer players. Upon arrival, participants will complete a health history questionnaire to determine which group participants will be placed. Surface electromyography will be used to determine muscle activity of the biceps femoris, medial hamstrings (semitendinosus and semimembranosus), rectus femoris, and vastus lateralis. Manual muscle tests will be performed to collect baseline muscle activation. Next, both participant groups will complete the modified agility T-test (MAT), and the depth jump assessment in randomized order. For the depth jumps, a 6-inch box and a 12-inch box will be used. Following three attempts, only the second jump from each height will be taken for analysis due to the Hawthorne effect. Average muscle activation during cutting and jumping events of each test will be analyzed and compared to baseline muscle activity collected during manual muscle testing. For statistical analysis, a between-subjects ANOVA will be run to analyze the differences observed between groups. Collection of data is underway. We expect to see a lower H:Q ratio during the modified agility T-test and depth jump assessments in those with previous ACL injury. A lower H:Q ratio, indicating quadriceps dominance, is expected in those with previous ACL injury due to increased susceptibility of anterior translation of the tibia facilitated by a weakened hamstring muscle group and load compromised ACL.