Gastrocnemius tendon length and strain are different when assessed using straight or curved tendon model.

Stosic, J.; Finni, T.

The present study investigated the effects of tendon curvature on measurements of tendon length using 3D-kinematic analysis. Curved and straight tendon models were employed for assessing medial gastrocnemius tendon length and strain during hopping (N = 8). Tendon curvature was identified using small reflective markers placed on the skin surface along the length of the tendon and a sum of vectors between the markers from the calcaneous up to the marker at the origin of tendon was calculated. The straight tendon was defined as a length of vector from the calcaneous to the marker at the origin of tendon. The curved tendon method yielded 5.0 ± 1.3 mm longer tendon (p < 0.001) than the straight tendon model. Tendon elongation was 2.1 ± 1.6 mm and peak strain 1.3 ± 0.7% smaller in curved than in straight tendon model (p < 0.01). The results suggest that the commonly used straight tendon model underestimate slightly but significantly the true tendon length but overestimate the strain and elongation.

TENDONS; SKELETAL muscle; PHYSIOLOGIC strain; HUMAN body; HUMAN physiology; TENDON physiology; SKELETAL muscle physiology; BIOLOGICAL models; KINEMATICS; BODY movement; PHYSIOLOGY; ANATOMY

European Journal of Applied Physiology, 2011, Vol 111, Issue 12, p3151

1439-6319

Academic Journal

10.1007/s00421-011-1929-9