Force Control Norms during Leg Press Exercise in Healthy Subjects
Advisor Information
Dr. Brian Knarr
Location
MBSC 201
Presentation Type
Poster
Start Date
6-3-2020 12:30 PM
End Date
6-3-2020 1:45 PM
Abstract
INTRODUCTION: Although knee pathology patients are often cleared to return to full activities following rehabilitation, many don’t re-engage in activities they did prior to pathology. Current rehabilitation focuses on strengthening the quadriceps through exercises like the leg press, however, it is difficult to objectively evaluate the quality of the forces produced during these exercises. Using a custom force platform, we are able to measure the forces during the leg press and evaluate their control using a nonlinear metric called the Lyapunov exponent. Establishing normative values of force control in healthy populations provides a point of comparison for pathological populations that can be used in the future. PURPOSE: To develop norms for force control during the leg press in healthy individuals. METHODS: Fourteen healthy subjects performed continuous repetitions of the leg press for two-minutes at a cadence of 60 bpm and load of 20% of their one-repetition maximum. Force data was collected using a custom force platform and used to calculate Lyapunov exponents for the dominant limb, non-dominant limb, and both limbs together (total). Descriptive statistics were calculated for Lyapunov exponents. RESULTS & DISCUSSION: Lyapunov exponents for the total, dominant limb, and non-dominant limb were 7.19±2.88, 8.46±2.96, and 7.90±2.39 respectively. These values provide a set of normative values for healthy individuals to be used to make appropriate comparisons against individuals with knee pathologies such as anterior cruciate ligament injury and knee osteoarthritis in future work.
Force Control Norms during Leg Press Exercise in Healthy Subjects
MBSC 201
INTRODUCTION: Although knee pathology patients are often cleared to return to full activities following rehabilitation, many don’t re-engage in activities they did prior to pathology. Current rehabilitation focuses on strengthening the quadriceps through exercises like the leg press, however, it is difficult to objectively evaluate the quality of the forces produced during these exercises. Using a custom force platform, we are able to measure the forces during the leg press and evaluate their control using a nonlinear metric called the Lyapunov exponent. Establishing normative values of force control in healthy populations provides a point of comparison for pathological populations that can be used in the future. PURPOSE: To develop norms for force control during the leg press in healthy individuals. METHODS: Fourteen healthy subjects performed continuous repetitions of the leg press for two-minutes at a cadence of 60 bpm and load of 20% of their one-repetition maximum. Force data was collected using a custom force platform and used to calculate Lyapunov exponents for the dominant limb, non-dominant limb, and both limbs together (total). Descriptive statistics were calculated for Lyapunov exponents. RESULTS & DISCUSSION: Lyapunov exponents for the total, dominant limb, and non-dominant limb were 7.19±2.88, 8.46±2.96, and 7.90±2.39 respectively. These values provide a set of normative values for healthy individuals to be used to make appropriate comparisons against individuals with knee pathologies such as anterior cruciate ligament injury and knee osteoarthritis in future work.