Abstract

Background. Muscle strength is an important tool for the assessment of muscle function and is strongly influenced by body size. Therefore, utilization of strength body-size-independent measurements for muscle strength testing is important in comparing the strength measured in large populations. Mechanical low back pain is the commonest musculoskeletal disorder in clinical practice and is associated with gluteus maximus weakness and hamstring tightness. Objective. This study aimed to determine the correlation between hamstring length and gluteus maximus strength with and without normalization in patients with mechanical low back pain. Methods. Seventy-three patients diagnosed with mechanical low back pain participated in this study. First, gluteus maximus strength was measured isometrically as a force (kg) and then converted to torque (Nm). Gluteus maximus strength was normalized for body weight and height using the following formula:% (body weight × height) = torque (N × m) ×100 / body weight (N) × height (m), then the hamstring length was measured using the active knee extension test. Results. The study population consisted of 38 females and 35 males with mean age, body mass and height values of 31.42 ± 6.78 years, 75.63 ± 12.77 kg, and 170.43 ± 9.24 cm respectively. The Spearman product-moment correlation between hamstring length and gluteus maximus strength revealed that there was a positive strong correlation (p < 0.05) between hamstring length and gluteus maximus strength with and without normalization. Conclusion. Contrary to our expectations, there was a highly significant positive correlation between gluteus maximus strength (with normalization) and hamstring length, and a positive correlation between gluteus maximus strength (without normalization) and hamstring length.

Key words:

Hamstring length, Gluteus maximus strength, Normalization, Mechanical low back pain