Relationship between Pain Intensity, Activity Limitation, Static and Dynamic Back Muscles Endurance in Patients with Non-specific Longterm Low-back Pain

Research on the correlation of trunk muscles’ endurance with other outcome measures in patients with long-term low-back pain (LBP) is scarce. This study assessed the relationship between pain intensity, activity limitation, and static and dynamic back extensors endurance in patients with non-specific long-term LBP. Sixty-seven patients screened using the McKenzie Institute’s Lumbar Spine Assessment Format participated in this study. Quadruple visual analog scale and the Roland-Morris disability questionnaire were used to assess pain and activity limitation respectively. Modified Biering-Sorensen test of muscular endurance and repetitive arch-up test were used to assess static endurance (SE) and dynamic endurance (SE) respectively. Data were analyzed using mean, standard deviation, range, Pearson’s product moment correlation and stepwise regression at 0.05 Alpha level. Mean present pain, Roland-Morris score (RMS), SE and DE were 6.55 ± 1.75, 9.22 ± 0.75, 37.64 ± 14.0 secs and 11.43 ± 3.03 repetitions respectively. Significant correlation was found between present pain and each of SE (r=-0.306; p=0.012) and RMS (r--0.862; p=0.001). SE and DE showed a direct moderate significant correlation with each other (r=0.519; p=0.001). Regression analysis showed that age (p=0.012) and sex (p=0.051) were significantly related to SE, age was significantly related to DE (p=0.003) while pain intensity was significantly related to RMS (p=0.001). It is concluded that increase in pain intensity is associated with decreased static back extensors endurance and activity limitation. Static and dynamic back endurance was significantly positively correlated while age was a significant predictor of static and dynamic endurance. It is recommended that management focus of non-specific long-term LBP should address deficit in static and dynamic back muscles endurance beside pain and activity limitations.