Development of a Distance-Based Interval Throwing Program for Little League-Aged Athletes

Abstract

We developed a distance-based interval throwing program for Little League-aged athletes (9 to 12 years) to be used in training and rehabilitation. The timing and repetition parameters were developed from data collected during 400 innings of organized baseball during a single season, and short toss distance from Little League rules for field dimensions. There were 1022 boys from organized baseball teams in the four studies. Maximal distance and speed measurements were recorded for 853 boys. We developed a mathematical model from these data to predict maximal throwing distance from maximal throwing speed. This model was then tested on a second sample of 114 players. We compared the predicted distance with the actual maximal throwing distance; the correlation coefficient was 0.92. Forty players aged 9 to 12 participated in a study to assess degradation of speed and distance. The average variability of the speed was small (< 5 mph), but the variability in distance was large (22.4 feet). Fifteen boys then threw the entire throwing program as designed. These results show that healthy young athletes can be expected to be able to throw the predicted value of this practical progressive interval throwing program for Little League-aged athletes. The appropriate program can be assigned from age and known preinjury pitch speed.

Biomechanical Comparison of Baseball Pitching and Long-Toss: Implications for Training and Rehabilitation

“…28,29 The interval throwing program starts skeletally mature players at a throwing distance of 45 ft (14 m) and progressively increases it to 180 ft (55 m). 3,22 For all flat-ground throws, the player is verbally instructed to use "crow-hop" footwork, to throw "on a line" (a hard throw with a low trajectory), and to use proper mechanics. 3,22,28,29 The use of proper mechanics-the mechanics used by healthy players-is a critical aspect of the interval throwing program.…”

“…3,22 For all flat-ground throws, the player is verbally instructed to use "crow-hop" footwork, to throw "on a line" (a hard throw with a low trajectory), and to use proper mechanics. 3,22,28,29 The use of proper mechanics-the mechanics used by healthy players-is a critical aspect of the interval throwing program. It has been suggested that pitching coaches and sports biomechanists provide a valuable service on a rehabilitation team to ensure proper mechanics.…”

“…Theoretically, the progression of throwing phases allows an injured athlete to gradually recover his arm flexibility, arm strength, and proper throwing mechanics. 3,22,28,29 Interval throwing programs have been utilized to effectively return pitchers and position players to baseball.…”

Baseball Injuries

“…These regulations apply to all pitchers within a youth league organization [59]. A difficulty with this regulatory system is that younger pitchers tend to throw more pitches per inning than older pitchers because they have less control over their pitches because of lack of experience, greater musculoskeletal immaturity, or both [60]. Therefore, with innings limits, those with potentially weaker and less developed arms are throwing more pitches than those with stronger arms.…”

Interval Sport Programs: Guidelines for Baseball, Tennis, and Golf

“…9,10 Upon successful completion of the early phases of the rehabilitation program, a gradual and controlled return to sport activities has been advocated by several authors. 1,2,3,6,9,10,11 The term ''interval sport programs'' has been used to refer to functional rehabilitation guidelines that simulate sport activities. These programs are designed to progressively apply forces to the healing structures and are intended to gradually return the athlete to full athletic competition as quickly and safely as possible.…”