title: Gastrocnemius tendon length and strain are different when assessed using straight or curved tendon model.
abstract: 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.
authors: Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä, Finland.
authors: J
authors: J
authors: Stosic
authors: T
authors: T
authors: Finni
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D009068:Movement / Q000502:physiology; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000502:physiology*; D013710:Tendons / Q000033:anatomy & histology / Q000502:physiology*