Comparison of finger kinematics between patients with hand osteoarthritis and healthy participants with and without joint protection programs.

STUDY DESIGN: This is a cross-sectional, clinical observational study. BACKGROUND: Finger range of motion (ROM) and functional performance are critical in many daily activities. Hand osteoarthritis (H-OA) is a prevalent disease that impairs both variables. Little quantitative research has been performed on finger kinematics during activities of daily living (ADLs) across health status and method of performance (with or without joint protection programs). PURPOSE: The purpose of this research is to examine the effects of H-OA and method of performance on ROM in the thumb, index, and middle digits (flexion/extension and abduction/adduction) during ADLs. METHODS: This study was conducted using 10 healthy participants (mean age: 28 years) and nine participants with H-OA (mean age: 72 years). All participants performed baseline ROM movements followed by 9 activities of daily living. These activities involved prehension type grasps and were performed with and without the recommended joint protection procedures specific to each task. Thumb IP and MCP, index distal interphalengeal (DIP) and proximal interphalengeal (PIP), and middle DIP and PIP joints were continuously recorded using an electromagnetic tracking system for ROM analysis. RESULTS: Participants with H-OA had a statistically significant decrease in ROM when comparing values measured in the healthy cohort during active ROM (25° decrease) and ADL ROM (25° decrease) in the flex/ext direction. Similarly, following joint protection instruction, a statistically significant decrease in ROM was found during tasks in the flex/ext direction (healthy participant decrease in ROM: 17°, H-OA decrease in ROM:10°) CONCLUSIONS: This study demonstrated that people with hand arthritis move through a smaller arc of motion when performing some functional tasks as compared with the controls, and that with instruction on joint protection techniques, participants made significant changes in the amount of movement used to perform tasks, which supports a proof of principle of joint protection.

A method for measuring in vivo finger kinematics using electromagnetic tracking.

Accurate in vivo measurement of finger joint kinematics is important for evaluation of treatment methods, implant designs, and for the development and validation of computer models of the hand. The main objective of this project was to develop a standardized finger kinematic measurement system employing electromagnetic (EM) tracking to measure in vivo finger motion pathways. A landmark digitization protocol was developed and used in vivo, in a biomechanical study using EM trackers secured to the finger segments. In vivo results for finger flexion/extension showed no significant differences between EM and goniometer results, 5°±3°; p = 0.735.