Upper extremity joint stresses during walker-assisted ambulation in post-surgical patients

Background: A walker is a common device prescribed for ambulatory assistance for individuals with balance difficulties or to reduce lower extremity demands following injury or surgery. The long-term use of a walker imposes significant demands on the patient's upper extremities that may lead to increased risk for development of secondary conditions such as wrist, elbow or shoulder pain. Objective: To describe the joint kinematics, forces and moments of the wrist, elbow and shoulder in a sample of twenty patients that were using a walker as a result of total joint surgery of the hips and knees. Methods: Three-dimensional upper extremity kinematics were recorded using a motion capture system synchronized with forces and torques transmitted through a walker instrumented with force transducers in the handles. Results: Compressive forces were found to be nearly 20% of the body weight at each of the upper extremity joints, both surgical and non-surgical sides, being the greatest force at the wrist and decreasing proximally. Compression forces were greater in the non-surgical side limb at the wrist and at the elbow. Conclusion: Our findings indicated that loads on upper extremity joints associated with the use of a walker for assisted ambulation are high and further studies are needed to address the cause-effect relationship between the actual joint loading and the development of secondary musculoskeletal upper extremity complaints in more frail patients.