Mechanical properties of muscles and tendons in asymptomatic individuals with generalized joint hypermobility

Abstract

Background. The purpose of the present study was to investigate changes in mechanical properties of muscles and tendons in asymptomatic individuals with generalized joint hypermobility (GJH). Methods. This cross-sectional study was conducted in 126 participants aged 19-40 years. The Beighton score was used to determine whether the participants had GJH. An experienced physiotherapist screened all participants using the Beighton score to inquire about the presence of GJH. At the end of the clinical evaluations, 36 asymptomatic participants with GJH (age, 24.6 ± 6.1 years) and 34 age-and sex-matched controls (age, 24.6 ± 6.8 years) were included in the present study. The oscillation frequency (indicator of tone), dynamic stiffness (indicator of stiffness), and logarithmic decrement (related to elasticity) of the medial and lateral gastrocnemius, biceps brachii, and brachioradialis muscles, and the Achilles and patellar tendons were measured with a portable myotonometer (MyotonPRO, Myoton AS, Tallinn, Estonia). Results. The oscillation frequency, dynamic stiffness, and logarithmic decrement of the biceps brachii, brachioradialis, and medial and lateral gastrocnemius muscles were similar in GJH and control groups (p > 0.05). In addition, there was no significant difference between groups in terms of the oscillation frequency, dynamic stiffness, and logarithmic decrement of the Achilles and patellar tendons (p > 0.05). Conclusions. The elasticity, stiffness, and/or tone of the biceps brachii, brachioradialis, and medial and lateral gastrocnemius muscles were similar in individuals with and without GJH. The results obtained suggest that the mechanical properties of muscles and tendons are not associated with GJH.