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Y. Tokuda1, K. Arai2, S. Omori3, T. Kato4, R. Takeuchi5, Y. Yabuta6
1Teikyo Heisei University, Department of Physical Therapy, Tokyo, Japan, 2Kenoh Tokorozawa Hospital, Department of Rehabilitation Medicine, Saitama, Japan, 3Tokyo General Hospital, Department of Rehabilitation Medicine, Tokyo, Japan, 4Clover Hospital, Department of Rehabilitation Medicine, Kanagawa, Japan, 5Saiwaitsurumi Hospital, Department of Rehabilitation Medicine, Kanagawa, Japan, 6Hospitality Care Garden Seisei Rehabilitation Hospital, Department of Rehabilitation Medicine, Shizuoka, Japan
Background: Gastrocnemius is key muscle during walking acceleration. Few studies report the difference in gastrocnemius muscle activities during heel rise, walking, and manual resistance.
Purpose: The objective of this study was to clarify the characteristics of gastrocnemius muscle activities during heel rise, walking, and manual resistance.
Methods: We enrolled healthy young adult (age: 20 to 22 years old, 9 men [height: 170.1 ± 5.6 cm, weight: 64.9 ± 7.4 kg] and 11 women [height: 161.1 ± 7.2 cm, weight: 55.5 ± 8.9 kg]) for the study. A hand-held dynamometer and EMG (sampling frequency: 1,000 Hz) were used to capture the data during plantar flexion with and without manual resistance in the prone position. Thereafter, we applied 16 reflective body markers to each subject. A three-dimensional motion analysis system (sampling frequency: 100 Hz), force plate (sampling frequency: 1,000 Hz), and EMG (sampling frequency: 1,000 Hz) were used. The subjects walked barefoot at moderate speed (1.3 ± 0.2 m/s) on a 9-meter walking path in the laboratory. Thereafter, the individuals stood on the right limb and performed heel rises with extended knee 5 times (a heel rise period: 1.7 ± 0.1 seconds) on the force plate. The maximum root mean square of EMG amplitude with Butterworth filter (20 to 400 Hz passed) were measured using each trial. Speed, ankle joint moment, reaction force, pelvis and heel elevation were measured while walking and during heel rise. Statistical analysis was performed using t-test and Wilcoxon signed-rank test at a 5% significance level.
Results: The following results were obtained (expressed as mean ± standard deviation):
1) The maximum root mean square of EMG amplitude during heel rise (1.8 ± 1.2 mv) was significantly greater than that during walking (1.1 ± 1.1 mV).
2) The maximum ankle joint moment during heel rise (1,300.9 ± 189.0 N mm/kg) and that during walking (1,369.4 ± 257.3 N mm/kg) showed no significant difference. Ankle joint moment at the maximum root mean square of EMG amplitude during heel rise was 826.0 ± 133.0 N mm/kg and that during walking was 131.9 ± 206.4 N mm/kg.
3) The mechanical work of a heel rise (66.0 ± 16.4 J) was significantly greater than the mechanical kinetic energy of a walk (48.2 ± 17.5 J).
4) A significant correlation was seen between normalized maximum root mean square of EMG amplitude and mechanical work during heel rise.
5) The maximum root mean square of EMG amplitude with manual resistance against plantar flexion in the prone position and that during walking showed no significant difference.
1) The maximum root mean square of EMG amplitude during heel rise (1.8 ± 1.2 mv) was significantly greater than that during walking (1.1 ± 1.1 mV).
2) The maximum ankle joint moment during heel rise (1,300.9 ± 189.0 N mm/kg) and that during walking (1,369.4 ± 257.3 N mm/kg) showed no significant difference. Ankle joint moment at the maximum root mean square of EMG amplitude during heel rise was 826.0 ± 133.0 N mm/kg and that during walking was 131.9 ± 206.4 N mm/kg.
3) The mechanical work of a heel rise (66.0 ± 16.4 J) was significantly greater than the mechanical kinetic energy of a walk (48.2 ± 17.5 J).
4) A significant correlation was seen between normalized maximum root mean square of EMG amplitude and mechanical work during heel rise.
5) The maximum root mean square of EMG amplitude with manual resistance against plantar flexion in the prone position and that during walking showed no significant difference.
Conclusion(s): Thus, the gastrocnemius activities were greater during heel rise than those during walking. This could be attributed to the difference in the mechanical energy between a heel rise and during walk and not owing to the difference in ankle joint moment. When EMG amplitude was maximum during walking, the knee flexed rapidly, and the gastrocnemius muscle was loose. Although during heel rise, the knee extended, and the gastrocnemius muscle was tight, the differences in the EMG amplitude were more noticeable than those in the mechanical energies.
Implications: We believe that these results may be useful for muscle testing and exercise.
Funding, acknowledgements: This work was not supported by any foundation.
Keywords: gastrocnemius, muscle activities, motion analysis
Topic: Musculoskeletal: lower limb
Did this work require ethics approval? Yes
Institution: Teikyo Heisei University
Committee: Ethics Committee of Teikyo Heisei University
Ethics number: R01-076
All authors, affiliations and abstracts have been published as submitted.
