In high impact sports such as boxing, muay thai, and many other martial arts, athletes must train their hands to perform punches that will maximize damage to their opponent while balancing their own risk of injury. While some sports elect to use heavy padding to both support and cushion the hands, others rely more heavily on an athlete’s precision of technique to minimize injury. While hand and wrist injuries from punching techniques are less frequently cited as medical reasons to suspend participation in a sport, compared to other types of injuries, they nonetheless can lead to both acute and chronic conditions that impact an athlete’s performance.
The human hand has 27 small and delicate bones, all of which have the potential to be damaged from high impact strikes. In addition the wrist has eight small carpal bones that may sometimes become damaged from improper shock absorption after a forceful strike. Injuries to the hand and wrist can be either acute traumatic injuries or injuries from repeated stress and/or overuse. Acute injuries occur after a single, usually easily recognized event. These may include broken bones, muscle strains, sprains, tendon inflammation, and tears to the ligament. By contrast stress-induced injuries are built up after an accumulation of many hours of stressful training and are usually characterized by pain, chronic inflammation, and/or wearing away at tendons or ligaments
The angle of the wrist upon the impact of a hand strike such as a straight punch is a critical factor for maximizing the force delivered to an opponent and also minimizing the striker’s risk of injury. If the wrist is in dorsiflexion (flexed upward as if making the universal sign for “stop”) or in palmar flexion (where the wrist pushes the palm downwards, much like forcefully dribbling a basketball) upon impact, damage to both the hand and wrist are possible. In particular fractures to the scaphoid bone, a small bone in the base of the wrist, are the most common. Scaphoid bone fractures are the top kind of reported fracture reported in boxers—accounting for about 60 percent of all carpal fractures. It is hypothesized that the small scaphoid bone is particularly at risk because the transfer of impact force travels down from the striking metacarpal bones. The force is passed to the smaller trapezium and trapezoid bones of the wrist and which then generate shearing stress on the scaphoid bone.
Another important factor for reducing the risk of injury when delivering a striking hand technique is the striking surface area. Trained boxers train themselves to deliver impact with the knuckles of the index and middle finger. This is because the connections that these two fingers have to the wrist are comparatively strong when contrasted against the oblique connections of the ring and little fingers. Fractures to the fourth and fifth metacarpals are sometimes referred to as “boxer’s fracture” because such fractures are produced from an improper punch that transfers force to these less-supported bones.
Different fighting styles train students differently in how best to deliver forceful punches while minimizing the risk of injury. While many systems will teach students to punch with the first two knuckles and the palm rotated downward, others such as some Chinese styles of martial arts will advocate for using more vertical punches that require three knuckles to better stabilize the wrist for punches that generate power from whip-like “snapping” motions. Other styles emphasize the use of strikes that use the heel or back of the hand to minimize the risk of self-inflicted injury.
By Sarah Takushi
AOSSM Sports Tips