Evaluation of Bilateral Asymmetry between Upper Limb Masses in Right-Handed Young Adults of Both Sexes

The study introduced a novel precise method for measurement and calculation of upper arm mass and to assess the difference between masses of upper limbs on the dominant and non-dominant sides of the body of right-handed participants. Forty healthy untrained male (n = 20; M age = 20.8yr., SD = 1.2) and female (n = 20; M age = 20.7 yr., SD = 1.3) participants without a history of upper-extremity pathology participated. Kinematic and kinetic data were collected during arm motion. The mass of each arm was calculated. Each participant performed 20 movements with each arm. Most often the dominant arm was more massive than the non-dominant in both sex groups; however, mass was more symmetric for female participants than for male participants. Regression equations related to total body mass were calculated for each arm independently.