Abstract Title

Influence of Knee Wraps on Force Production during Passive Isometric Quadriceps Contractions

Abstract

Purpose: To observe the effect of wearing knee wraps on passive isometric torque production at varying degrees of knee flexion. Methods: Nine recreationally active men (22.9 ± 3.7 yrs; 177.3 ± 5.7 cm; 84.9 ± 17.4 kg) completed one experimental visit. Prior to testing, participants’ height, weight, body composition (13.9 ± 7.0%) and knee circumference (37.8 ± 2.0 cm) were recorded. Participants then completed a one-repetition maximum (1-RM) in the back squat and were considered to be resistance trained after completing a 1-RM of at least 1.5x their body weight. Qualified participants then performed passive isometric force tests on their right leg using a HUMAC Isokinetic Dynamometer. Forces were recorded at 100Hz for nine different angles (70° - 110° at 5° increments, lasting 5 seconds each): two with the right knee wrapped (KW), and two unwrapped (UW). Knee wrap trials were separately wrapped between attempts. Data were analyzed via within-subjects repeated measures ANOVA. Results: A significant condition x angle interaction was observed (F=218.677; p≤0.0001, ηp2 =0.965). Post hoc analyses revealed significant differences between all angles for KW (p≤0.005), and between angles greater than 90° for UW (p≤0.05). Paired samples t-tests revealed significantly greater force production in KW compared to UW at all angles (p≤0.05) excluding 70°(p=0.205). Conclusion: Applying knee wraps significantly increases passive isometric forces at angles greater than 70° of knee flexion when compared to the unwrapped condition. Furthermore, knee wraps produce greater forces as the angle of flexion increases.

Modified Abstract

Purpose: Examine the effect of knee wraps on passive force production. Methods: Nine recreationally active men (22.9±3.7 yrs; 177.3±5.7 cm; 84.9±17.4 kg) completed one visit. Participants first had anthropometrics recorded, then completed a back squat one-repetition maximum (1-RM), requiring a load ≥ 1.5x their body weight to qualify. Participants then completed passive force tests on the HUMAC Isokinetic Dynamometer at various angles (70° - 110°), performing two trials with the knee wrapped (KW), and two unwrapped (UW). Results: A significant condition x angle interaction was observed (F=218.677; p≤0.0001, ηp2 =0.965). Paired samples t-tests revealed significantly greater force production in KW compared to UW at all angles (p≤0.05) excluding 70°(p=0.205). Conclusion: Knee wraps produce more passive force than unwrapped at all angles except at 70°.

Research Category

Social Science/Education/Public Health

Primary Author's Major

Exercise Science

Mentor #1 Information

Joseph

Laudato

Presentation Format

Poster

Start Date

April 2019

Research Area

Exercise Physiology | Exercise Science

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Apr 9th, 1:00 PM

Influence of Knee Wraps on Force Production during Passive Isometric Quadriceps Contractions

Purpose: To observe the effect of wearing knee wraps on passive isometric torque production at varying degrees of knee flexion. Methods: Nine recreationally active men (22.9 ± 3.7 yrs; 177.3 ± 5.7 cm; 84.9 ± 17.4 kg) completed one experimental visit. Prior to testing, participants’ height, weight, body composition (13.9 ± 7.0%) and knee circumference (37.8 ± 2.0 cm) were recorded. Participants then completed a one-repetition maximum (1-RM) in the back squat and were considered to be resistance trained after completing a 1-RM of at least 1.5x their body weight. Qualified participants then performed passive isometric force tests on their right leg using a HUMAC Isokinetic Dynamometer. Forces were recorded at 100Hz for nine different angles (70° - 110° at 5° increments, lasting 5 seconds each): two with the right knee wrapped (KW), and two unwrapped (UW). Knee wrap trials were separately wrapped between attempts. Data were analyzed via within-subjects repeated measures ANOVA. Results: A significant condition x angle interaction was observed (F=218.677; p≤0.0001, ηp2 =0.965). Post hoc analyses revealed significant differences between all angles for KW (p≤0.005), and between angles greater than 90° for UW (p≤0.05). Paired samples t-tests revealed significantly greater force production in KW compared to UW at all angles (p≤0.05) excluding 70°(p=0.205). Conclusion: Applying knee wraps significantly increases passive isometric forces at angles greater than 70° of knee flexion when compared to the unwrapped condition. Furthermore, knee wraps produce greater forces as the angle of flexion increases.