OBJECTIVES: This study investigated how age, sex, height, body weight, self-efficacy beliefs, pain, and subjective disability predict the performance of low back pain patients on an isokinetic trunk muscle test. METHODS: One hundred and five patients participated in the study. Dependent variables were isokinetic flexion and extension strength measured as total work done at speeds 50, 100, and 150 degrees/second. RESULTS: The anthropometric measures were poor predictors, height being the only significant one. Body weight and age were of no relevance for the performance. Subjective pain and disability had negative effects on the performance of men, but not of women. Self-efficacy beliefs, i.e., the patient's belief in his or her capability to endure physical activities, was the most powerful predictor. CONCLUSION: For the purpose of validation, standardization, and interpretation of isokinetic performance in low back pain patients, these factors should be taken into account.
OBJECTIVES: This study investigated how age, sex, height, body weight, self-efficacy beliefs, pain, and subjective disability predict the performance of low back painpatients on an isokinetic trunk muscle test. METHODS: One hundred and five patients participated in the study. Dependent variables were isokinetic flexion and extension strength measured as total work done at speeds 50, 100, and 150 degrees/second. RESULTS: The anthropometric measures were poor predictors, height being the only significant one. Body weight and age were of no relevance for the performance. Subjective pain and disability had negative effects on the performance of men, but not of women. Self-efficacy beliefs, i.e., the patient's belief in his or her capability to endure physical activities, was the most powerful predictor. CONCLUSION: For the purpose of validation, standardization, and interpretation of isokinetic performance in low back painpatients, these factors should be taken into account.