Acupuncture: A Match for Tennis Elbow Hypertrophy
Tennis elbow, a common tendinopathy of the outer elbow, was originally named after observing its prevalence in lawn tennis players in the late 1800’s. It is characterized by pain that originates at the outer elbow and is commonly referred to as "lateral epicondylitis“. Despite the name, this is a common injury that occurs in a variety of non-tennis related activities.
In a recent study published by Ural, et al. in 2017, acupuncture was shown to reduce tendon hypertrophy in patients diagnosed with this condition. Tendon hypertrophy, an indicator of more pronounced tendon pathologies, involves swelling and thickening of the tendon.
In this study, 41 patients (52 involved limbs, some patients had the condition bilaterally) were randomly selected into acupuncture and control groups. Both groups received conventional care which consisted of rest, nonsteroidal anti-inflammatory drugs, exercise, and bracing.
The acupuncture group was additionally given 10 treatments of acupuncture, 2-3 treatments per week, for a total of 10 treatments. The acupuncture points selected included one ashi point (literally meaning "oh, yes!" - the painful spot was located via palpation), LI 10, LI 11, LU 5, LI 4, and SJ 5. The needles were retained for 25 min.
In both groups the pain reduced and function improved, although with greater effect witnessed in the acupuncture group. What is unique about this study is that the common extensor tendon thickness, the hypertrophy that occurs with more advanced cases of tennis elbow, decreased in size but only in the acupuncture treatment group! These findings demonstrate an observable healing response that could be measured objectively with ultrasound and was unique to the acupuncture group.
There are several research articles published which use these same acupuncture points to demonstrate objectively how acupuncture benefits Tennis Elbow.
So why these acupuncture points? The study does not articulate a clinical reasoning behind the point protocol. Listed below are some simple explanations to entice the reader into thinking about anatomical correspondences along with clinical applications.
LI 10 targets the extensor carpi radialis brevis, the most common muscle-tendon unit involved in tennis elbow. This muscle has been shown to consist of fibrous bands and tendinous arches that can entrap the radial nerve which mimics tennis elbow. When appropriate, the location can be altered slightly to reach the radial tunnel directly.
LI 11 treats the extensor carpi radialis longus which effects biomechanics of the underlying extensor carpi radialis brevis and increases underlying friction against the capitulum.
LU 5 targets the radial nerve at the cubital fossa. The radial nerve innervates all of the possible pain generators associated with tennis elbow.
LI 4 targets the superficial radial nerve and sympathetic nerve fibers associated with the dorsal radial artery. This decreases neural tone and neuromodulates pain sensitization.
SJ 5 targets the posterior interosseous nerve, a branch of the radial nerve. It is a commonly used acupuncture point for pain along the shoulder and upper extremity. The San Jiao channel trajectory traverses the lateral elbow.
The ashi point chosen usually targets the supinator muscle in these types of clinical studies. It can be a causative pain generator but is also involved with radial nerve entrapment. Clinically speaking, the extensor digitorum communis would also be an excellent choice as an ashi point when indicated.
More information on how to assess and specifically treat the above points can be found in my webinar: Tennis Elbow: Assessment, Treatment, & Self-Care.
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Reference: 1. Ural, et al. Ultrasonographic Evaluation of Acupuncture Effect on Common Extensor Tendon Thickness in Patients with Lateral Epicondylitis: A Randomized Controlled Study. JACM, 2017