Decelerate to vaccinate: putting the brakes on sports injury

Paper Title: Deceleration Training in Team Sports: Another Potential ‘Vaccine’ for Sports-Related Injury

Publication: Sports Med

Publication date: October 2021

INTRODUCTION

Sprinting improves performance and reduces the risk of injury. Deceleration precedes a change of direction (COD) and reduces momentum when slowing down while running. High-intensity deceleration occurs more often than acceleration in team sports, such as football, hockey, rugby, and soccer. At the same time, deceleration training involves high-impact braking ground reaction forces that predispose the lower limb to tissue damage, loss of stiffness, and neuromuscular fatigue. In addition, athletes require coping strategies to handle the high-intensity deceleration demands of matches and training. Therefore, deceleration training may provide clinicians with an alternative strategy to reduce injury risk.

METHODOLOGY

This narrative review provides a background for deceleration training to improve performance and reduce injury. In addition, the authors investigated theoretical frameworks to develop deceleration training methods.

CLINICAL IMPLICATIONS

High-intensity horizontal decelerations are performed frequently in team sport match play and possess unique biomechanical and physiological characteristics.

Deceleration Properties	Injury Consideration	Performance Consideration
Deceleration increases the: 1. Magnitudes of horizontal braking impulse in foot2. Impact peak force and loading rates3. Joint angular velocity	1. Increase musculoskeletal loading2. Eccentric power absorption in the lower body	Helps in force application for re-acceleration into a new direction
Eccentric training forces are greater than those in concentric or isometric training	Increased force leads to muscle damage and greater neuromuscular and mechanical fatigue	Increased mechanical & metabolic efficiency
Increased quadriceps and greater relative hamstring activation	Reducing the risk of anterior displacement of the tibia ultimately reduces the risk of ACL injury	Increase braking force
Increased pre-impact muscle activation and mechanical buffering capacity of the tendon	Reduce the rate of active muscle fascicle lengthening and eccentric force inputs	Increased ability to generate and attenuate intense braking forces
Increase sarcomeres in series and tissue tolerance	Reduce the adverse effects of muscle damage and neuromuscular fatigue	Increased expression of force-velocity characteristics

CONSIDERATIONS

Team sport requires athletes to develop robust musculoskeletal capacity and adapt to high-intensity horizontal deceleration. Clinicians should carefully monitor athletes’ deceleration training load, assess compensatory movement strategies, and formulate acceleration-deceleration profiles to maximize performance and reduce injury risk. The use of high-speed cameras, radar technology, and satellite tracking systems may improve evaluation and monitoring during deceleration training. Future research needs to investigate the optimal deceleration training dose.