Kinetic Arm Effects on Throwing Mechanics - Abstract Study

Examining the Kinetic Arm Throwing Sleeve and Its Effects on Throwing Mechanics

Brittany Dowling, MS Director of Biomechanics at Midwest Orthopaedics at Rush 

Dr. Ryan Balmes, DPT with American Board of Physical Therapy Specialities in Orthopaedic Physical Therapy and Sports Physical Therapy

Introduction: Addressing Elbow Injuries in Overhead Athletes

Elbow injuries are prevalent among overhead throwing athletes, particularly baseball players. Despite various methods designed to manage throwing volume—such as pitch counts, inning limits, and restrictions on pitch types—elbow injuries continue to rise at all levels of play, from high school to professional baseball. In fact, research has not demonstrated a clear link between pitch counts or inning limits and reduced injury risk in baseball pitchers (Zareminski et al., 2018; Saltzman et al., 2018). In response to this growing concern, innovative solutions like the Kinetic Arm device have been developed to alleviate stress at the elbow during throwing. This study investigates the impact of the Kinetic Arm on throwing biomechanics, specifically focusing on elbow varus torque, arm rotational velocity, arm rotation, and arm slot.

Methods: A Rigorous Evaluation of the Kinetic Arm Device

The study involved 8 high school and collegiate baseball players (average age: 18.8 ± 2.9 years; height: 71.8 ± 1.9 in; weight: 183.9 ± 32.2 lbs). The players were evaluated at the Elite Edge facility in Chamblee, GA. Each player wore a motus biomechanics sensor and sleeve to measure critical metrics. Players were given unlimited time to warm up before performing two sets of throws: one without the Kinetic Arm device and another while wearing the device. Each throw was made into a target on a net at a distance of 20 feet with maximum effort, and players were permitted to crow-hop between throws.

The following metrics were recorded during each throw: elbow varus torque, arm rotational velocity, arm rotation, and arm slot. Ball velocity was also recorded using a radar gun (Pocket Radar, Santa Rosa, CA). Paired t-tests were used to compare the throwing conditions, with a significance level set at p < 0.05.

Results and Discussion: Key Findings

The results revealed a significant decrease in elbow varus torque when players wore the Kinetic Arm device (p = 0.01). However, there were no significant differences in arm rotation, arm speed, or arm slot between the two conditions. This outcome highlights the Kinetic Arm’s ability to reduce the stress on the elbow joint while maintaining throwing mechanics, specifically elbow alignment during the throwing motion.

The Kinetic Arm device offers a unique approach to managing biomechanics in throwing athletes. This intervention can be applied across all phases of an athlete's season, including preseason, in-season, and post-season, for both injury prevention and rehabilitation. The Kinetic Arm could serve as a rehabilitative tool, similar to how post-operative ACL patients might use aquatic therapy to facilitate a return to running. By providing controlled support to the elbow, it helps to reduce the risk of injury while still allowing athletes to maintain their performance levels.

Conclusions: A Game-Changer for Throwing Athletes

The findings from this study indicate that wearing the Kinetic Arm device does not alter an athlete's throwing mechanics, yet significantly reduces elbow varus torque, which can help reduce the risk of injury. The Kinetic Arm shows promise as a rehabilitative assistive device for throwing athletes in the return-to-sport phase, offering a workload management tool to reduce stress at the elbow. Further research will be essential to confirm its effectiveness across different populations of athletes and determine its long-term benefits.

References:

  1. Zareminski et al. (2018). Orthopedic Journal of Sports Medicine.
  2. Saltzman et al. (2018). Journal of Shoulder and Elbow Surgery.
  3. Boddy et al. (2019). PeerJ.

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This research reinforces the potential of the Kinetic Arm as an essential tool in managing throwing mechanics and reducing the risk of elbow injuries. Whether used for injury prevention, rehabilitation, or overall performance optimization, the Kinetic Arm stands out as a key innovation in arm care for baseball players.