Thoracic Spine Range of Motion and Rotational Power

By Dan Donohue, MS, RSCC – Cincinnati Reds

There are multiple factors to consider when designing programs to help athletes increase rotational power during competition. One aspect that strength and conditioning coaches emphasize is thoracic spine mobility / thoracic spine rotation. There are several exercise and corrective movements that can be used to help optimize thoracic spine (T-spine) range of motion (ROM). Once an acceptable ROM is achieved, coaches can help athletes convert T-spine passive ROM (PROM) into T-spine active range of motion (AROM).

Because baseball is a rotational sport, providing athletes with the tools to increase mobility, flexibility and range of motion in a given joint, multiple joints and/or movement pattern(s) is essential for enhancing performance and reducing the risk of injury. Incorporating adequate T-spine range of motion and velocity into strength and conditioning programs should help increase velocity when throwing and hitting and reduce the risk of injury¹.

If one of the primary goals of training baseball players is to improve rotational power, one can assume that some form of rotation exercise should be included in each player’s year-around conditioning program.  This assumption is supported by research by Szymanski, et. al.² Szymanski and his colleagues examined the effects of adding rotational MD ball throws to resistance training on rotational strength and velocity. The investigators had two groups of high school baseball players perform resistance training three times per week for 12 weeks and take 100 swings per workout with a 30-ounce baseball bat. One group also performed two sets of six rotational exercises with 5 kg MD balls two times per week for the first four weeks, two sets of 6 reps with 4 kg MD balls for the middle four weeks and two sets of 6 reps with 3 kg MD balls for the last four weeks. While both groups made significant gains in strength, post-test data indicated that the improvements in angular hip velocity, angular shoulder velocity, linear bat-end speed velocity, hand velocity, torso rotational strength and rotational MD ball throwing distance were significantly higher in the group that performed MD rotational throws as part of their training program. The data suggested that improving T-Spine rotation can help improve performance by increasing movements associated with throwing velocity and bat speed.

Research on professional and club level cricket athletes indicated that athletes who threw faster generated more force and greater workout than those who threw slower³. The data also indicated that the slower throwers exhibited greater range of motion in the thoracic and hip regions. The authors concluded that the reduced range of motion in the proximal regions (thoracic and hip) is more useful for transferring momentum from the lower extremity to the upper extremity during explosive movements like throwing. Conversely, they concluded that the greater the range of motion at the proximal segments may not help improve throwing velocity in cricket. The takeaway from this study is that the faster throwers had less range of motion resulting in greater active range of motion and therefore were able to capitalize on the muscles stretch-shortening cycle and length-tension relationship to increase power output.

The aforementioned research emphasizes the importance of not only creating passive range of motion to increase the effectiveness of the stretch-shortening cycle and length-tension principle, but also the importance of transitioning from passive to active range of motion. Exercise movements designed to improve in passive and active T-spine range of motion and strength can be used year-around to improve rotational power and help reduce the risk of injury.

Because most players swing and lift from only one side, asymmetrical loading and chronic adaptations are common in baseball. Incorporating T-spine mobility drills into the training program can be used to help counter-act some of the effects of asymmetrical loading and avoid one-sided athletes. Past experience indicates that performing T-spine mobility drills 1-2 times per week on lighter resistance training days can help reduce some of the asymmetrical pre- and in-season demands of the game. Because the volume of swings and throws is significantly less in the post- and off-season, the frequency of T-spine training can be increased to 2-3 times per week.

During pre-season and in-season training, the focus should be on improving mobility and increasing range of motion by performing 2-3 sets of isometric holds at the end range of motion (Table 1). The last set should use a slow and controlled tempo of active movement to help acquire activation throughout the newly acquired range of motion.

During the post-season and off-season, the focus should shift to increasing active and total range of motion (Table 2). This will be accomplished by reaching the end range of motion and eccentrically loading each rep back to the original starting position. The last set will consist of slow and controlled tempo active movement to help acquire activation throughout the new range of motion.

The ultimate goal is to enhance performance and reduce the risk of injury by increasing T-spine passive and active range of motion using a balanced, effective, minimal dose of training. Strength and Conditioning Coaches can be instrumental in helping players adapt and reduce risk of injury while promoting an increase in power output throughout the training year.

References

1. Stodden DF, et. al. Comparison of trunk kinematics in trunk training exercises and throwing. J Strength Cond Res, 22(1):112-118, 2008.

2. Szymanski DJ, et. al. Effect of torso rotational strength on angular hip, angular shoulder, and linear bat velocities of high school baseball players. J Strength Cond Res, 21(4):1117-1125, 2007.

3. Talukdar K, et. al. The role of rotational mobility and power on throwing velocity. J Strength Cond Res. 29(4):905-911, 2015.

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Dan Donohue, MS, RSCC, CSCS, PES, CES, FRCms, FMS-1, CC, is the Strength and Conditioning Coach for the Dayton Dragons; Midwest League affiliate of the Cincinnati Reds.