The Validity of Applying a Simple Three-Factor Computational Model to Calculate Force, Power, and Speed Using Hexagonal Bar Jumps

Agar-Newman, DJ, Tsai, MC, and Klimstra, M. The validity of applying a simple three-factor computational model to calculate force, power, and speed using hexagonal bar jumps. J Strength Cond Res XX(X): 000-000, 2020-The development of athlete specific force-speed profiles can be accomplished through testing ballistic movements, enabling athlete comparisons and to direct training interventions. However, field-based assessments relying on the squat jump or countermovement jump may lack specificity for some sports or be contraindicated for some athletes. Therefore, the purpose of this study was to assess the validity of a three-factor computational model using system mass, push-off distance, and jump height to calculate force, speed, and power for the hexagonal bar (hex-bar) jump. Twenty-one university varsity rowing athletes (12 females and 9 males, 20.40 ± 2.60 years, 78.56 ± 13.68 kg, 1.77 ± 0.08 m, and strength training history of 3.57 ± 2.69 years) were purposefully sampled. Testing consisted of jumps at loads starting at 28.55 kg and increasing by 10-kg increments to 78.55 kg or until technical failure occurred. Validity was assessed by comparing the three-factor computational model to the criterion force-time measures from a force plate. The results show force (mean bias = 85.38 N, SE = 5.41, 95% confidence limit 1,576.85-1,598.19), speed (mean bias = 0.00 m·s, SE = 1.25, 95% confidence limit 0.72-0.72), and power (mean bias = 73.36 W, SE = 3.90, 95% confidence limit 1,166.61-1,181.97) can be computed using a three-factor computational model using the hex-bar jump. In conclusion, jump height from a hex-bar jump can be used with a simple three-factor computational model to calculate valid measures of force, speed, and power. This allows practitioners in the field to use a movement that may be more sport-specific or safe, to calculate kinetic and kinematic measures without encountering the issues of cost and portability associated with force plates.