Closed-kinetic chain resistance training (CKCRT) of the lower body is superior to open-kinetic chain resistance training (OKCRT) to improve performance parameters (e.g., vertical jump), but the effects of upper-body CKCRT on throwing performance remain unknown. This study compared shoulder strength, power, and throwing velocity changes in athletes training the upper body exclusively with either CKCRT (using a system of ropes and slings) or OKCRT. Fourteen female National Collegiate Athletic Association Division I softball player volunteers were blocked and randomly placed into two groups: CKCRT and OKCRT. Blocking ensured the same number of veteran players and rookies in each training group. Training occurred three times weekly for 12 weeks during the team's supervised off-season program. Olympic, lower-body, core training, and upper-body intensity and volume in OKCRT and CKCRT were equalized between groups. Criterion variables pre- and posttraining included throwing velocity, bench press one-repetition maximum (1RM), dynamic single-leg balance, and isokinetic peak torque and power (PWR) (at 180 degrees x s(-1)) for shoulder flexion, extension, internal rotation, and external rotation (ER). The CKCRT group significantly improved throwing velocity by 2.0 mph (3.4%, p < 0.05), and the OKCRT group improved 0.3 mph (0.5%, NS). A significant interaction was observed (p < 0.05). The CKCRT group improved its 1RM bench press to the same degree (1.9 kg) as the OKCRT group (p < 0.05 within each group). The CKCRT group improved all measures of shoulder strength and power, whereas OKCRT conferred little change in shoulder torque and power scores. Although throwing is an open-chain movement, adaptations from CKCRT may confer benefits to subsequent performance. Strength coaches can incorporate upper-body CKCRT without sacrificing gains in maximal strength or performance criteria associated with an athletic open-chain movement such as throwing.

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The approach shot is critical to golf performance, demanding precise control of distance, direction, and trajectory. Despite real-world importance, three-dimensional kinetic assessment of approach skill is lacking. We evaluated ground reaction forces (GRFs) of 6-iron approach shots of normal/stock (ST), high-draw (HD), and low-fade (LF) trajectories struck by 31 tournament professional and plus-handicap amateur golfers. A priori hypotheses were: HD would involve greater and earlier peak lead foot vertical GRF in the downswing (DS); and/or greater peak differences in DS anterior-posterior (AP) GRF, compared to ST and LF. Analysis of variance and post hoc testing supported our hypotheses. Peak lead foot vertical GRFs were 100.4%, 101.1%, and 103.8% of body-weight for ST, LF, and HD, respectively (P < 0.001). Peak vertical GRF occurred later in the DS when executing LF (P < 0.05). The peak difference in AP GRF was greater when executing HD (P < 0.001). Timing and magnitudes of GRF peaks varied widely between golfers. Even among accomplished golfers executing ST (their most reliable trajectory), standard deviations ranged from 18.7% to 72.7% of mean values. Between-golfer differences accounted for 89.9%-93.6% of the total variance. These data may encourage researchers and coaches to avoid rigid standards or generalized recommendations for GRF parameters as relates to performance.