MUSCULAR WEAKNESS ASSESSMENT - USE OF NORMAL ISOMETRIC STRENGTH DATA

Objective: Assessment of muscle strength is vital to the management of patients with muscular weakness. Clinical interpretation of isometric strength data for individual patients has been limited because of the lack of a reference population for comparison. The purpose of this st udy was to develop regression equations to predict maximal isometric s trength based on gender, age, height, and weight. Patients' absolute s trength values may then be expressed as a percentage of their predicte d values, facilitating the determination of presence and extent of wea kness. Design: Three separate neuromuscular research groups developed databases of normal maximal isometric strength values, using standardi zed testing procedures. The databases were combined into a single data base, and multiple regression equations were formulated for strength p rediction for the 20 muscle groups tested. Setting: Seven neuromuscula r research units, each within the neurology department of a university -based teaching facility. Subjects: A convenience sample of 493 volunt eers who had no medical conditions that would have prohibited them fro m performing a maximal isometric strength test. Main Outcome Measure: Maximal isometric strength (kg) of ten muscle groups was measured bila terally. Results: Regression equations and 95% prediction intervals ar e derived from the combined database. A case study demonstrates the us e of the predictive equations in determining presence and extent of we akness. Conclusion: Predictive strength equations facilitate assessmen t of muscular weakness. (C) 1996 by the American Congress of Rehabilit ation Medicine and the American Academy of Physical Medicine and Rehab ilitation.