The purpose of this study is to examine the relationship between ankle plantarflexor strength and the angular velocity of ankle plantarflexion during the heel raise movement.
Eleven healthy adult males (22 feet, mean age 27.6 ± 4.2 years, height 172.4 ± 2.4 cm, weight 68.6 ± 7.2 kg) participated. Ankle plantarflexor strength was measured in a single-leg stance using a squat rack and barbell to assess isometric plantarflexor strength with a force plate. The barbell on the squat rack was fixed at shoulder height, and the subjects performed a single-leg stance with the knee joint in the extended position and the ankle in a neutral position. They performed isometric ankle plantarflexion for 3 seconds, taking sufficient rest, for a total of 3 trials. Heel raises were measured using a three-dimensional motion analysis system on a force plate. To maintain balance, the subjects were instructed to use two fingers for support and to raise their heels as quickly as possible, taking sufficient rest in between, for a total of three trials. The calculated items included ankle plantarflexor strength, defined as the maximum value of the vertical component on the force plate, divided by body weight and expressed as a percentage. The heel raises were assessed for mean angular velocity and peak angular velocity during the movement, with averages calculated from the 3 trials. Statistical analysis examined the correlation between ankle plantarflexor strength and both peak and mean angular velocities. Results were considered statistically significant at p0.05.
Isometric ankle plantarflexor strength was 269.4 ± 51.0%, mean angular velocity was 131.0 ± 26.6 °/s, peak angular velocity was 238.0 ± 51.7 °/s. The correlation analysis showed that the relationship between ankle plantarflexor strength and mean angular velocity was r = 0.55 (p 0.05), while the relationship between ankle plantarflexor strength and peak angular velocity was r = 0.60 (p 0.05).
A moderate correlation was found between ankle plantarflexor strength and the angular velocity of ankle plantarflexion during heel raises. This suggests the possibility of predicting ankle plantarflexor strength using heel raises.
This study suggests that heel raises could provide a simple, accessible way to estimate ankle plantarflexor strength without specialized equipment. Further research is needed to confirm its accuracy and broader use in rehabilitation.
angular velocity
three-dimensional motion analysis
