A bilateral comparison of the underlying mechanics contributing to the seated single-Arm shot-put functional performance test

Context: Functional performance tests (FPTs) are tools used to assess dynamic muscle strength and power. In contrast to the lower extremity, fewer FPTs are available for the upper extremity. The seated single-Arm shot put test has the potential to fill the void in upper extremity FPTs; however, the underlying mechanics have not been examined and, therefore, the validity of bilateral comparisons is unknown. Objective: To examine the effects of upper extremity dominance and medicine-ball mass on the underlying mechanics of the seated single-Arm shot put. Design: Crossover study. Setting: Biomechanics laboratory. Patients or Other Participants: Fifteen women (age=23.6 6 2.1 years, height=1.65 6 .07 m, mass=68.1 6 11.7 kg) and 15 men (age = 24.3 6 4.0 years, height = 1.80 6 0.06 m, mass = 88.1 6 16.4 kg), all healthy and physically active. Intervention(s): Seated single-Arm shot-put trials using the dominant and nondominant limbs were completed using three 0.114-m-diameter medicine-ball loads (1 kg, 2 kg, 3 kg). Main Outcome Measure(s): Customized touch-sensitive gloves, synchronized with kinematic data of the hands, signaled ball release, so that release height, release angle, and peak anterior and vertical velocity could be quantified for each trial. In addition, the horizontal range from release to first floor impact was recorded. Results: The dominant-limb horizontal ranges were 7% to 11% greater (P < .001) than for the nondominant limb for each of the 3 ball masses. No bilateral release-height or-Angle differences were revealed (P ≥ .063). Release velocities were 7.6% greater for the dominant limb than the nondominant limb (P = .001). Conclusions: Our results support the use of the seated single-Arm shot put test as a way to compare bilateral upper extremity functional performance. The near-identical release heights and angles between the dominant and nondominant limbs support the interpretation of measured bilateral horizontal-range differences as reflecting underlying strength and power differences.