Relationship between Balance and Physical Activity in Subjects with Non-Specific Chronic Low Back Pain

Most research on sedentary lifestyle has focused on pain and disability outcomes, while neuromuscular outcomes (postural control and strength) have received less attention. The objective of the present study was to determine whether low level of physical activity is negatively associated with measures of lower body muscular strength and postural control in subjects with and without non-specific chronic low back pain (NSCLBP). Twenty-four subjects with NSCLBP (28.8±5.9 years) and 24 age, gender, and Body Mass Index (BMI) matched healthy controls participated in the study. Subjects were sub-classified into four subgroups based on their level of physical activity using the International Physical Activity Questionnaire Short Form (IPAQ-SF) – (Group A: Nonactive, NSCLBP; Group B: Active NSCLBP; Group C: Non-active healthy control; and Group D: Active healthy control). Each subgroup consisted of 12 subjects, 6 males and 6 females. Following a familiarization session, assessments of hip muscular strength and postural control were performed. Peak force of hip extensors, flexors, abductors, and external rotators was assessed using a handheld dynamometer. Postural control was assessed using computerized posturography and the Y Balance Test. There was no significant group by physical activity interaction for strength and static and dynamic postural control, except for static control during left single leg stance with eyes closed (p=0.029). However, there was a significant difference in strength, static and dynamic postural control by physical activity level (p<0.05). Postural control and peak force of the hip muscles strength were significantly associated with physical activity level (r ranged from 0.50-0.66, p < 0.001 and r ranged from 0.40-0.59, p < 0.05, respectively). Postural control and hip strength were independently related to physical activity behavior. The present results suggest that sedentary behavior may be an important risk factor for impaired postural control an