R. Wellmon, MS, PT, MossRehab Hospital, Philadephia, PA

RA Newton, PhD, PT, Department of Physical Therapy, Temple University

 

Asymmetrical weight bearing (AWB) during standing and locomotion is a common impairment exhibited by individuals who have experienced a cerebral vascular accident (CVA). AWB is believed to be due to an inability to weight bear fully on the paretic or involved limb. As a result, the post-CVA individual is thought to be at risk for falls, and is reportedly less functional for both ambulation and activities of daily living. Traditional neurotherapeutic approaches have emphasized using weight shifting activities to facilitate weight bearing on the paretic limb as a method for correcting AWB. However, the efficacy of such approaches for causing changes in motor performance leading to a more symmetrical pattern of gait and standing has not been validated clinically. The purpose of this study is to examine the effectiveness of using a weight shifting task to improve weight bearing symmetry for standing and locomotion in individuals with a diagnosis of a CVA.

Twenty-one subjects admitted as inpatients to a free standing rehabilitation hospital with a diagnosis of a CVA were randomly assigned to either a treatment or control group. Subjects in the treatment group (n=12) practiced a weight shifting task designed to simulate the demands of the single stance phase of gait and encourage weight bearing on the paretic limb. In standing, subjects practiced shifting their weight onto the paretic lower extremity (LE) while lifting the non-paretic LE from the support surface and placing it on a step. One repetition of the task was completed when the non-paretic LE was returned to the original starting position. The task was practiced for 20 minutes, twice a day for two days. Subjects in the control group (n=9) did not practice the task. The dependent variables, which were measured before and after each treatment session, were preferred pattern of weight bearing in standing, step length, and single stance time.

A 2 (group) by 8 (sessions) analysis of variance with repeated measures on the last factor was performed on standing symmetry, step length symmetry, and single stance symmetry scores. Symmetry scores were calculated using simple ratios of affected limb performance to unaffected limb performance. No significant differences were found between the treatment and control groups across the sessions for standing symmetry [F(7,133)=0.41, p=0.89], single stance symmetry [F(7,133)=0.63, p=0.73], and step length symmetry [F(7,133)=0.03, p=0.95].

For the sample participating in the study, the results indicate that the weight shifting activity was not effective in causing a significant change in the pattern of AWB for standing and locomotion. Contrary to the previously held notions of the traditional neurotherapeutic approaches, weight shifting activities may not be effective in producing the intended outcome. In light of this and other studies, clinicians may need to reevaluate the use of weight shifting activities as means to promote motor skill.

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Poster presentated at American Physical Therapy Association, 1997 Combined Sections Meeting, Dallas, TX.

Poster presented at the 9th Annual Stroke Conference, Boston, MA, 1997.

Research conducted in fulfillment of the MS degree in Physical Therapy from Temple University, College of Allied Health Professions, Philadelphia, PA.