Clinical aspects of overuse tendon inquiry and experimental aspects of tendon properties

This thesis was aimed at increasing knowledge about tendons. Two studies were conducted. The clinical study documented the history of symptoms in a population of patients with Achilles tendinitis (n = 53). The average total time with symptoms was 18 months, from onset of pain to full recovery. In addition, symptomatic patients with sonographically normal tendons recovered more quickly than patients with abnormal tendons. The experimental study evaluated the stress-strain properties and surface strain distribution of isolated cat patellar tendons (n = 9), during in-vitro submaximal loading. The stress-strain curves at different loading rates were similar. Marked load relaxation occurred when the same tendon specimen was loaded repeatedly. Surface strains were found to be non-uniform. Strain near the insertions was found to be significantly higher than in the mid-substance of the tissue, at a stress level of 20 MPa.