Spring-Mass Model Characteristics in Distance Runners Across a Competitive Season
Abstract
The spring-mass model (SMM) explains the elastic bouncing nature of the lower limbs during running as the tendons store and release elastic energy. It is primarily used to explain sprinting and is less understood in distance runners. SMM is quantified by evaluating the asymmetries in landing-takeoff and rebound percents (%) determined from ground reaction forces (GRF). Faster runners have less asymmetrical landing-takeoff% and more asymmetrical rebound%. SMM asymmetries may be sensitive to longitudinal training. Therefore, we sought to document changes in elastic bouncing properties over a 7-week competitive season in distance runners. Thirteen university runners (age, 19.8±2.2 yrs; height, 1.74±0.10 m; mass, 61.9±9.0 kg) ran on an instrumented treadmill where GRF data were collected pre- and post-season. Landing-takeoff asymmetry was calculated as relative time durations of push-off (tpush) to braking (tbrake) horizontal GRF. Rebound asymmetry was calculated as relative time durations of effective aerial (tae) to effective contact (tce) vertical GRF. A paired t-test showed no significant changes in landing-takeoff asymmetry (pre, 103.7±13.2 vs. post, 102.3±19.2%; t(12)=0.232, p=0.82), but the mean values showed good symmetry (close to 100). While rebound asymmetry increased, it was not significant (pre, 160.4±16.1 vs. post, 164.4±20.8%; t(12)=-1.239, p=0.239). Vertical GRF magnitude was also not significantly changed (pre, 25.1±2.8 vs. post, 25.2±2.7 N/kg; t(12)=-0.074, p=-0.942). While individual runners improved elastic bouncing, SMM characteristics appear to remain stable across a competitive running season. Improving rebound asymmetry may not be as important in distance running. Year-round monitoring may yield further insight into elastic bouncing development.
Faculty Sponsors
Dr. Monique Mokha
Project Type
Event
Location
Alvin Sherman Library
Start Date
4-3-2024 12:30 PM
End Date
4-4-2024 1:30 PM
Spring-Mass Model Characteristics in Distance Runners Across a Competitive Season
Alvin Sherman Library
The spring-mass model (SMM) explains the elastic bouncing nature of the lower limbs during running as the tendons store and release elastic energy. It is primarily used to explain sprinting and is less understood in distance runners. SMM is quantified by evaluating the asymmetries in landing-takeoff and rebound percents (%) determined from ground reaction forces (GRF). Faster runners have less asymmetrical landing-takeoff% and more asymmetrical rebound%. SMM asymmetries may be sensitive to longitudinal training. Therefore, we sought to document changes in elastic bouncing properties over a 7-week competitive season in distance runners. Thirteen university runners (age, 19.8±2.2 yrs; height, 1.74±0.10 m; mass, 61.9±9.0 kg) ran on an instrumented treadmill where GRF data were collected pre- and post-season. Landing-takeoff asymmetry was calculated as relative time durations of push-off (tpush) to braking (tbrake) horizontal GRF. Rebound asymmetry was calculated as relative time durations of effective aerial (tae) to effective contact (tce) vertical GRF. A paired t-test showed no significant changes in landing-takeoff asymmetry (pre, 103.7±13.2 vs. post, 102.3±19.2%; t(12)=0.232, p=0.82), but the mean values showed good symmetry (close to 100). While rebound asymmetry increased, it was not significant (pre, 160.4±16.1 vs. post, 164.4±20.8%; t(12)=-1.239, p=0.239). Vertical GRF magnitude was also not significantly changed (pre, 25.1±2.8 vs. post, 25.2±2.7 N/kg; t(12)=-0.074, p=-0.942). While individual runners improved elastic bouncing, SMM characteristics appear to remain stable across a competitive running season. Improving rebound asymmetry may not be as important in distance running. Year-round monitoring may yield further insight into elastic bouncing development.
