Musculo-tendinous and joint elastic characteristics during elbow flexion in children

Objective. The aim of the present research was to determine joint stiffness and musculo-tendinous stiffness in children. Background. No reliable data was available on differences in such parameters when comparing children and adults. Methods. Sinusoidal perturbations and quick-released movements were applied to the right elbow during flexion to determine joint stiffness and musculo-tendinous stiffness, respectively. For normalization purposes, stiffness indexes were calculated as the slope of the relationship between stiffness and torque. Results. Main results were that musculo-tendinous stiffness indexes obtained in children were similar to adult data deduced from the literature. On the other hand, joint stiffness indexes obtained in children were in the range 0.9–3.8 rad−1 and were lower than those reported in the literature for adults (between 4 and 8.5 rad−1). Conclusion. Since normalized musculo-tendinous stiffness is similar in children and in adults, it can be hypothesized that, during growth, increase in ability to produce force parallels elastic tissue development.