These results suggest that the paretic maximal grip strength, normalized with the maximal grip strength on the nonaffected side, appears to be a valuable outcome measure of upper extremity function in chronic stroke subjects.

The recovery of locomotion, following interactive training with graded weight support, in the adult spinal cat has led to the proposal that removal of body weight may be a therapeutic tool in human gait retraining. There would be benefits, however, in knowing normal responses of humans to partial weight bearing before applying this strategy to patients. In this study, 10 nondisabled male subjects walked on a treadmill while 0%, 30%, 50%, and 70% of their body weight was supported by a modified climbing harness. To dissociate the changes attributable to walking speed from those attributable to body weight, each subject walked at the specified body-weight-support (BWS) levels and at full weight bearing (FWB) at the same speed. Simultaneously, electromyographic data from the right leg muscles, footswitch signals, and video recording of joint motion were collected. The FWB and BWS gaits appeared similar, except at the highest level of BWS studied (ie, 70% of BWS). Significant differences among other BWS and FWB trials at comparable speeds included decreases in percentage of stance, percentage of total double-limb support time, and maximum hip and knee flexor swing angle. Other adaptations to BWS were a reduction in the mean burst amplitude of the muscles that are active during stance and an increase in the mean burst amplitude of the tibialis anterior muscle. The possible implications of this new gait retraining strategy for patients with neurological impairment are discussed. [Finch L, Barbeau H, Arsenault B. Influence of body weight support on normal human gait: development of a gait retraining strategy.

Background: Low-back pain is responsible for significant disability and costs in industrialized countries. Only a minority of subjects suffering from low-back pain will develop persistent disability. However, this minority is responsible for the majority of costs and has the poorest health outcomes. The objective of the Clinic on Low-back pain in Interdisciplinary Practice (CLIP) project was to develop a primary care interdisciplinary practice model for the clinical management of lowback pain and the prevention of persistent disability.

The purpose of this study was to verify the usefulness of an adaptation of the stress process model in organizing the psychological variables associated with the development of low-back-pain related disability. French-speaking Canadian workers on compensated sick leave (N=439) due to recent occupational low back pain (LBP) were evaluated during the sub-acute stage of LBP (between 30 and 83 days after injury). They were assessed for the following factors: life events, injury-specific cognitive appraisal, emotional distress, avoidance coping, and functional disability. Confirmatory factor analyses were used to test and modify the measurement model. An important modification in the measurement model was the association of catastrophizing with the emotional distress factor. During the sub-acute stage, path analyses revealed a satisfactory fit of the following model (the following coefficients are standardized): (a) life events (.30) and cognitive appraisal (.42) explained emotional distress (r(2)=.30); (b) emotional distress (.42) and cognitive appraisal (.36) explained the use of avoidance coping (r(2)=.45); and (c) emotional distress (.24) and avoidance coping (.56) explained functional disability (r(2)=.53). The stress model tested here reaffirms the importance of life events in the development of disability through the more established emotional distress factor. Also, cognitive appraisal appears to have an indirect effect on disability through activity avoidance and distress. This adaptation of the stress model makes it possible to integrate risk factors into a reduced set of meaningful factors and proposes a more general adaptation explanation of disability than the specific fear-avoidance model.