Activity-dependent enhancement of balance in persons with Parkinson's disease following strength and balance trainin

A growing body of evidence points toward an increase in falls and fall related injuries in persons with Parkinson's disease (PD). The role of high intensity lower extremity strength training and balance training in the reduction of falls for this population has not been thoroughly investigated through controlled studies. The primary purpose of this study was (1) to present to what extent falls could be reduced by strength and/or balance training, (2) to present to what extent balance scores could improve, and (3) to present to what extent daily activities (Activities of Daily Living) were affected by the intervention. Sixteen persons (M age 72) with stage I-III PD were randomized into one of two groups; one receiving strength and balance training (Combined), the other receiving balance training only (Balance). Balance was tested using the EquiTest, a dynamic posturography device which measures posture sway under six sensory conditions. Subjects were pre-tested, post-tested following 10 weeks of training, and tested again after a one month follow up, during which time no training was permitted. Data were analyzed using repeated measures MANOVA. Both groups reduced the number of falls from pre to post-test. The Combined group attained significant improvements in strength. There were no significant changes in EquiTest equilibrium scores. Clinical improvements were noted during sway-referenced support conditions, with eyes open, eyes closed and vision sway-referenced. Falls were reduced from pre to posttest for both groups and from post to followup test for the Combined group. The Combined group maintained their falls reduction throughout the follow-up period, while the Balance group's falls frequency returned to baseline. ADL were unaffected by the intervention. This suggests that there may be a long term training effect on falls reduction caused by a greater reliance on muscle strength than on visual, vestibular or proprioceptive mechanisms, which is not reflected in EquiTest equilibrium sway scores. Improvements in muscular strength, balance and functional ability attributed to the intervention support the importance of regular strength and balance training in the prevention of fall-related injury for persons with Parkinson's disease.