Neuromuscular mechanics and hopping training in elderly
Version 2 2024-06-06, 20:07Version 2 2024-06-06, 20:07
Version 1 2015-01-12, 15:01Version 1 2015-01-12, 15:01
journal contribution
posted on 2024-06-06, 20:07authored byM Hoffrén-Mikkola, M Ishikawa, T Rantalainen, J Avela, PV Komi
Purpose: The present study examined the effects of repetitive hopping training on muscle activation profiles and fascicle–tendon interaction in the elderly. Methods: 20 physically active elderly men were randomly assigned for training (TG) and control groups (CG). TG performed supervised bilateral short contact hopping training with progressively increasing training volume. Measurements were performed before the training period (BEF) as well as after 2 weeks (2 W) and 11 weeks (11 W) of training. During measurements, the gastrocnemius medialis–muscle (GaM) fascicle and its outer Achilles tendon length changes during hopping were examined by ultrasonography together with electromyographic (EMG) activities of calf muscles, kinematics, and kinetics. Results: At 2 W, the ankle joint stiffness was increased by 21.0 ± 19.3 % and contact time decreased by 9.4 ± 7.8 % in TG. Thereafter, from 2–11 W the jumping height increased 56.2 ± 18.1 % in TG. Simultaneously, tendon forces increased 24.3 ± 19.0 % but tendon stiffness did not change. GaM fascicles shifted to shorter operating lengths after training without any changes in their length modifications during the contact phase of hopping. Normalized EMG amplitudes during hopping did not change with training. Conclusions: The present study shows that 11 W of hopping training improves the performance of physically active elderly men. This improvement is achieved with shorter GaM operating lengths and, therefore, increased fascicle stiffness and improved tendon utilization after training. Based on these results, hopping training could be recommended for healthy fit elderly to retain and improve rapid force production capacity.
History
Journal
European journal of applied physiology
Volume
115
Pagination
863-877
Location
Heidelberg, Germany
ISSN
1439-6319
Language
eng
Publication classification
C Journal article, C1 Refereed article in a scholarly journal