The term 'tennis elbow' was introduced in 1880's, also known as lateral epicondylitis or lateral epicondylalgia . It is the most common source of elbow pain in the general population . It is a soft tissue condition frequently associated with overuse injury, primarily occurring at the aponeurosis of the common extensor origin at the elbow. The common complaints of the individual are pain during wrist extension which is localized to the common extensor origin and decreased grip strength, both of which may affect the activities if daily living . Lateral epicondylitis or epicondylalgia is usually caused by repetitive wrist extension that leads to an overuse injury, followed by micro-tearing of Extensor Carpi Radialis Brevis (ECRB) and occasionally the Extensor Digitorum Communis (EDC) Muscle and Extensor Carpi Radialis Longus (ECRL) muscle [2, 4, 5]. Examination reveals pain with passive wrist flexion and active and resisted wrist extension. Tenderness is located 1 to 2 cm distal to the lateral epicondyle .
Lateral epicondylitis is associated with many athletic and non-athletic endeavours . The annual incidence of lateral epicondylitis is 1% to 3% in the general population. The tennis players account for less than 5% of the population, and exhibit 40% to 50% chance of having lateral epicondylitis at some point in time . Although rarely seen in the elite players 50% of the recreational players can expect to experience this condition at some point of their playing lifetime . Lateral epicondylitis is a condition that primarily occurs in the recreational tennis players . The non-athletic population accounts for 35% to 64% of the population affected by lateral epicondylitis .
The force overload implicated in lateral epicondylitis is attributed to the repetitive strong synergistic and fixator role played by the wrist extensors during gripping [2, 3]. Gripping activates the flexor muscles thereby creating a flexion moment at the wrist joint and as a result the extensor muscles are co-activated, producing an extension moment that stabilizes the wrist joint.
Recent electromyographic studies have supported the concept that the wrist extensors play a key role in gripping and that ECRB, EDC, ECRL muscles are all activated during gripping . It has been concluded that application of an external wrist extension force reduces EMG activity of the wrist extensors muscles during gripping in healthy volunteers .
Thus, wrist extensors play an important role in maintaining wrist in extension and their affection in lateral epicondylitis may hamper the activities of daily living. In 1980, WHO classified lateral epicondylitis as a disability as it often limits the work capacity . It is widely accepted that grip strength provides an objective index of the functional integrity of the upper extremity [7–12]. In clinical setting, grip strength is commonly evaluated by an instrument called dynamometer, which measures static grip strength and is widely accepted to measure the grip strength [13, 14].
A number of studies have been done to report the influence of elbow positions on grip strength in subjects with lateral epicondylitis [15–17]. At the time the idea of the study was conceived no study could be retrieved which showed the effect of wrist extension position on grip strength in chronic lateral epicondylitis or one which gives an objective comparison of the grip strength between athlete and non-athlete subjects following chronic lateral epicondylitis. Hence we decided to do a study to determine the grip strength at two different wrist extension positions comprising of 15° and 35° in chronic lateral epicondylitis and to compare the grip strength between the athlete and non-athlete subjects with chronic lateral epicondylitis. This would help in finding the most optimum position in the assessment and treatment of patients with lateral epicondylitis.