Muscle Power Output Properties Using the Stretch-shortening Cycle of the Upper Limb and Their Relationships with a One-Repetition Maximum Bench Press

Abstract

The purpose of this study was to examine the output properties of muscle power by the dominant upper limb using SSC, and the relationships between the power output by SSC and a one-repetition maximum bench press (1 RM BP) used as a strength indicator of the upper body. Sixteen male athletes (21.4Ϯ0.9 yr) participated in this study. They pulled a load of 40% of maximum voluntary contraction (MVC) at a stretch by elbow flexion of the dominant upper limb in the following three preliminary conditions: static relaxed muscle state (SR condition), isometric muscle contraction state (ISO condition), and using SSC (SSC condition). The velocity with a wire load via a pulley during elbow flexion was measured accurately using a power instrument with a rotary encoder, and the muscle power curve was drawn from the product of the velocity and load. Significant differences were found among all evaluation parameters of muscle power exerted from the above three conditions and the parameters regarding early power output during concentric contraction were larger in the SSC condition than the SR and ISO conditions. The parameters on initial muscle contraction velocity when only using SSC significantly correlated with 1 RM BP (rϭ0.60-0.62). The use of SSC before powerful elbow flexion may contribute largely to early explosive power output during concentric contraction. Bench press capacity relates to a development of the above early power output when using SSC.

Relationship Between Upper-Body Strength and Bat Swing Speed in High-School Baseball Players

“…Hence, the bench press is frequently used by power athletes like baseball players aiming to improve performance in spite of having the differences with actual movement or agonist muscle (8).…”

Relationships between Stretch-shortening Cycle Performance and Maximum Muscle Strength

“…To account for systematic error, the rotary encoder and load cell were calibrated before each measurement. Test-retest reliability was at peak power ICC = 0.89, and the cross correlation coefficients between trials for time-series power parameters exerted from each preliminary condition were high (r = 0.75-0.99, P , 0.05) (20).…”

“…The use of SSC in the upper limbs is extremely effective in enhancement of initial muscle contraction velocity (20). Therefore, the following muscle power parameters were selected in reference to a previous study (20): 1) 0.1 s velocity during concentric contraction (m/s), 2) peak velocity (m/s), 3) time to peak velocity (s), 4) 0.1 s initial power (W), 5) peak power (W) (Figure 2).…”

Gender Difference in Ability Using the Stretch-Shortening Cycle in the Upper Extremities

“…However, because the influence caused by elastic components is temporary (initial phase), and the contractive force of muscle (contractile component) finally contributes to peak velocity, the correlation between peak velocity under both conditions may have been high. Even if the potentiation of SSC is observed in the initial phase of force exertion in the upper extremities, it disappears in the latter half (23,33). Therefore, it is possible that the SSC ability of the upper extremities cannot be properly evaluated with only peak performance (peak power) such as the jumping height of the lower extremities.…”

“…In addition, we assumed that a muscle power output difference between the SR condition and the SSC condition was related to a difference in SSC ability, and we devised an index to evaluate SSC ability. It was reported that the use of SSC in the upper limbs is extremely effective in enhancement of initial muscle contraction velocity (23). Therefore, the initial power output value (0.1-second initial power) at which an SSC potentiation is observed conspicuously was adopted.…”