The Kinetic Chain and Tennis Injuries
Tennis is one of the most iconic international sports commonly referred to as a lifetime sport, one in which individuals of all ages can compete at all levels. The physical demands of the sport dictate the ability to repetitively exert short bursts of speed, power and explosiveness over the course of the match.
As a result, tennis players will be prone to injuries due to the high biomechanical, physiologic and repetitive demands of the sport. Tennis movements place stress on the athlete’s axial and extremity joints. The athletes I treat historically present symptoms with acute lower extremity injuries and chronic axial and upper extremity dysfunction.
The kinetic chain and efficient transfer of energy plays an important role in maximizing performance potential. The kinetic chain involves Newton’s Third Law of Motion wherein the lower extremity joints apply a force to the ground while the ground applies an equal force to the legs. The transfer of energy initiates at the feet and travels through the lower extremity joints and on to the core complex involving the trunk and back, upper extremity joints and ultimately to the racket. An interruption of this kinetic chain may result in dysfunction and injury.
For example, the tennis serve is the stroke that requires the highest joint torque and muscle force production within the sport. Research has shown that increasing serve velocity results in increased stress on the shoulder and elbow joints. However, increased lower extremity involvement such as a deep knee bend during the movement decreases the load placed upon the upper extremity joints.
A wide spectrum of dysfunctions and injury may occur depending on the location and timing of the interruption within the kinetic chain. The most common are chronic shoulder injuries due to the repetitive overhead serving motion which causes shoulder pain and instability symptoms. Elbow and wrist pain typically originate from tennis stroke deviations such as the wrist snap during serving and overhead strokes, and hitting ground strokes with an open stance.
Trunk injuries such as muscle strains are linked to increased trunk motion compensating for extremity weakness. These trunk injuries result from changes due to the amount of play intensity, duration of the matches and frequency of play. The most common lower extremity injury I see is acute ankle sprain due to ankle instability, proximal hip weakness or poor mechanics within the kinetic chain.
Optimizing the transfer of energy within the body’s kinetic chain can significantly reduce the occurrence of these injuries. After physical therapy, I always provide my patients with a strength and exercise program that is specific to addressing the interruptions within their kinetic chain. It is very important that the program is individual-specific due to the unique skill, abilities and morphologic structure of each tennis player. An athlete-specific therapy program can rehabilitate and prevent injury, improve on-court performance and achieve performance goals.
Dr. Rufino is a former collegiate tennis player and doctor of physical therapy at Avid Physical Therapy in Indio. He can be reached at firstname.lastname@example.org or (760) 347.6195.
Sources: 1) Dines JS, Bedi A, Williams PN, Dodson CC, Ellenbrecker TS, Altcheck DW, Windler G and Dines DM; 2) Tennis Injuries: Epidemiology, Pathophysiology and Treatment. J Am Acad Orthop Surg. 2015; 23:181-189