Kinematic Differences Between Dominant and Nondominant Upper Limbs During Reaching Task in Healthy Young Adults

Abstract

Background: Understanding the kinematic aspect is crucial in rehabilitation as it allows for the assessment and intervention of motor function, irrespective of underlying forces. Although numerous studies have examined upper limb kinematics in older populations, limited research has focused on healthy subjects. This study aimed to investigate kinematic differences between the dominant and non-dominant upper limbs during a reaching task among healthy young adults. Methods: A quantitative cross-sectional study was conducted at the Human Motion Lab. The study utilized wireless wearable sensor devices known as "Shimmer" to measure linear velocity, and the Edinburgh Handedness Inventory assessed hand dominance. Participants performed a reaching forward movement first with their dominant arm followed by their non-dominant arm. The collected data were converted into linear velocity and analyzed using MATLAB software. Results: The study recruited 28 healthy young adults (21.87±1.06 years: 11 males and 17 females). The results showed no significant differences in linear velocity between the dominant and non-dominant shoulders and elbow joints. However, a significant difference was observed in the wrist joint (MD = 0.84; 95% CI: 0.22 to 1.46; p = 0.01), with the dominant wrist exhibiting higher velocity during the reaching task than the non-dominant wrist. Conclusions: The results of this study suggest that similar strategies can be applied for functional task training in both shoulder and elbow joints, regardless of dominance site. However, it is essential to consider the specific needs of the wrist joint to optimize motor function in the upper limb, as its performance may be influenced by dominance status.