The Characteristics of Muscle Tone and Stiffness in Young Adults with Chronic Low Back Pain

Abstract

The prevalence of chronic low back pain (CLBP) in young adults is increasing; however, the biological mechanism of CLBP in this population remains unknown. PURPOSE: To observe the characteristics of muscle tone and stiffness (MTS) of relevant muscle groups in young adults with CLBP, in order to provide reference for rehabilitation and prevention of CLBP. METHODS: Twenty six subjects with CLBP (age: 22±2 years, 14 males and 12 females) were recruited as the experimental (E) group, while 29 healthy subjects (age: 25±2 years, 16 males and 13 females) were recruited as the control (C) group. The degree of pain (Visual Analogue Scale/Score, VAS) was recorded, and the MTS (indicators including F-Frequency, D-Logarithmic Decrement and S-Stiffness) of three muscle groups (para-spinal, hamstring and tensor fascia lata muscles) was assessed using the Myoton-3 equipment. Group differences were determined by using independent-sample t-tests; within the E group, MTS was compared between gender and degree of pain (VAS) using ANOVA. RESULTS:Compared with C group, the E group's MTS of all three muscles were significantly higher(p<0.05), and the differences were 11.4%, 10.0% and 14.9% respectively; E group showed bilateral imbalance in all three muscles, while C group did not show imbalance. With the E group, compared with female subjects, male subjects had higher MTS of tensor fascia lata and para-spinal muscles (p<0.05), and the differences were 12.8% and 20.0%, respectively; in addition, the MTS values of tensor fascia lata, hamstring and para-spinal muscles in the subjects with moderate pain (VAS 4-7) were higher than those with mild pain (VAS 1-3) (p<0.05), and the differences were 12.7%, 14.9% and 22.2% respectively. CONCLUSIONS: MTS is associated with considerable increase of hamstring, para-spinal muscle and tensor fascia lata in young patients with CLBP; Young CLBP patients had significant bilateral MTS imbalance of all these muscles; Young male CLBP patients had higher MTS in para-spinal muscle and tensor fascia lata than female patients; The more painful, the higher of the MTS in young CLBP patients.