BODY MOTION PATTERNS DURING A NOVEL REPETITIVE WHEEL-ROTATION TASK - A COMPARATIVE-STUDY OF HEALTHY-SUBJECTS AND PATIENTS WITH LOW-BACK-PAIN

Study Design. This study evaluated performance differences between pat ients with chronic low back pain and a control group during their perf ormance of a novel functional capacity task. Objective. To 1) evaluate strength and endurance differences between patients and control subje cts, 2) test for movement pattern differences between these groups, an d 3) evaluate how these patterns changed with repetitive performance o f the wheel-turning task. Summary of Background Data. Despite increase d emphasis quantifying functional capacities, few well-controlled stud ies comparing the performances of patients with low back pain with tho se of control subjects have appeared in the literature, particularly f or movement patterns. Methods. Forty patients with low back pain and 4 0 control subjects performed a sustained isodynamic wheel turning task . This task was selected because it simultaneously combined several co mmon pain-related movements. A set of kinematic measures to characteri ze the basic movement patterns during this task were developed. Result s. Control subjects produced significantly higher levels of static tor que and completed significantly more wheel-turning repetitions. Patien ts with low back pain exhibited significantly less upper torso and pel vic motion, upper torso rotations, and lateral trunk flexion than thos e in the control group. Conclusion. The dissimilar movement strategies found between the patients and control groups suggests that factors b eyond more global physical explanations (e.g., deconditioning) may be important in accounting for the large discrepancy between these groups regarding the amount of work performed. These finding, along with the basic kinematic patterns developed in this study, may have important implications for determining the efficacy of instruction in body mecha nics and treatment outcome for patients with chronic low back pain.