Clinical Review

Interval Throwing and Hitting Programs in Baseball: Biomechanics and Rehabilitation

Am J Orthop. 2016 March;45(3):157-162

References

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Finally, the follow-through phase occurs after contact with the baseball and ends with complete deceleration, completing the swing. In order to achieve optimal effort, full hip rotation is needed, which is aided by rotation of the trail foot. Both hips and back laces should face the pitcher upon completion of the swing producing maximum power output.¹⁵

Return to Hitting: Principles

As with the initiation of the ITP, an interval hitting protocol (IHP) is designed to begin only after the player has been assessed on impairment measures, physical performance measures, and self-assessment.¹⁷ The player should have minimum to no pain, have no tenderness to palpation, and show adequate range of motion and strength to meet the demands of performing a full hitting cycle.¹² It is recommended that before beginning a return-to-play protocol, the involved extremity should be at least 80% as strong as the uninvolved extremity.¹⁸ Physical measures challenging an athlete’s ability to perform tasks specific to hitting a baseball must also be considered through standardized examinations of the involved area.¹⁹ Finally, the athlete’s self-perception of functional abilities must be taken into account. This gives a subjective account of what the hitter perceives they are able to perform, providing useful insight into whether they are mentally prepared to participate in the protocol.

Like the ITP, progression through the IHP is also based on the player’s level of pain and soreness rather than following a specific timetable (Table). The program features a 1 day on, 1 day off schedule during which the player completes 1 step per day. The athlete must remain pain-free to progress to the next step and monitor his level of soreness during their workout. If pain or soreness persists, the player should rest for 2 days and be reevaluated upon return.¹⁷

The same principles of proper warm-up and mechanics apply in the IHP. An athlete should jog or cycle for a minimum of 10 minutes and perform stretching exercises focused on both upper and lower extremity muscles, as batting involves whole body movement. As the athlete progresses through the IHP, having a hitting coach to analyze, correct and maintain proper swing mechanics is valuable in enhancing performance as well as decreasing risk of re-injury.

The Interval Hitting Program

For a PDF patient handout that summarizes the phases of this program, see Appendix 2.

Phase 1 (Dry Swings). Only the most basic fundamentals are stressed during this phase. The player should focus on properly moving from one phase of the swing to the next, without the goal of hitting the baseball. Trainers should measure critical points in the swing and correct deficits early.

Phase 2 (Batting Off a Tee). In this phase, the player is reintroduced to batting at low intensity with a fixed position target. The initial steps have the batter swing in a position of greatest comfort and natural movement, while the final steps in this phase test the athlete’s range of motion and confidence in the previous, healed injury.

Phase 3 (Soft Toss). As the player progresses to this phase, a baseball with trajectory is used to simulate differences in placement of pitches used during a game. As the hitter is able to pick up differences in target position, his performance and confidence should both increase.²⁰ The coach should sit about 30 feet away, facing the hitter at an angle of 45°, and toss the ball in an underhand motion.

Phase 4 (Simulated Hitting). In this phase, the player and coach should focus on the timing of sequential body movements in order to elicit proper loading and force production. With the randomized pitch delivery and increased velocity, the hitter will practice against pitches similar to those delivered in competition.

Conclusion

Interval throwing and hitting programs are designed to allow the athlete to return to competition through a gradual, stepwise program. This permits the player to prepare his body for the unique stresses associated with throwing and hitting. The medical personnel should familiarize themselves with the philosophy of the interval throwing and hitting programs and individualize them to each athlete. Emphasis on proper warm-up, mechanics, and effort control is paramount in expediting return to play while preventing re-injury.