Lateral elbow pain is common in athletes. The first suspicion is always lateral elbow tendinopathy, which is statically accurate. Evan Schuman explains what could be happening when athletes don’t recover as expected. Perhaps something has been missed.
Tennis - French Open - Roland Garros - Kazakhstan’s Elena Rybakina in action during her first-round match against Belgium’s Greet Minnen REUTERS/Gonzalo Fuentes
When typical management strategies fail, lateral elbow pain can create a conundrum for clinicians. Lateral elbow tendinopathy is the most common pathology and responds well to appropriate de-loading and gradual loading. However, what happens when things don’t go to plan? Radial tunnel syndrome (RTS) presents very similarly to lateral elbow tendinopathy and presents in 5% of patients diagnosed lateral elbow pain(1-3). Radial tunnel syndrome is a true dynamic entrapment neuropathy that causes lateral elbow and proximal dorsolateral forearm without significant motor fall-out(1-4).
Radial tunnel syndrome is the most common cause of radial nerve branch entrapment, accounting for 1-2% of peripheral nerve entrapment in the upper limb. Moreover, it has a rare annual incidence of three in 100,000 cases. With such scarcity, one must wonder how many cases are misdiagnosed. Individuals with RTS often perform repetitive pronation and supination forearm movements of forearm pronation and supination. For example, manual laborers, machine workers, musicians, racquet sports, and heavy lifting(5). If these individuals present with lateral elbow pain, they most likely have lateral elbow tendinopathy, but clinicians must consider what else could be causing lateral forearm pain.
The Radial Nerve Pathway
The radial nerve is an extension from the posterior chord of the brachial plexus. It consists of nerve fibers from spinal nerve roots C5-T1. It arises in the axilla, where it separates from the posterior cord, anterior to the subscapularis, and travels along the posterior aspect of the upper arm(6,7). Then, it continues along the radial groove and supplies sensory and motor branches along its path(7).
Approximately three centimeters distal to the lateral epicondyle, the radial nerve divides into two branches – the superficial branch of the radial nerve (SBRN) and the posterior interosseus nerve (PIN)(7). The SBRN is a cutaneous sensory nerve that innervates the dorsal skin on the lateral aspect of the hand and the proximal dorsal surfaces of the thumb, index, and lateral half of the third finger(8). The PIN pierces between the two heads of the supinator muscle. It provides motor innervation to the common and deep extensors extensor of the forearm and sensory innervation to the dorsal wrist capsule via unmyelinated (group IV) afferent fibers. These fibers are associated with nociception, which may be why patients with PIN entrapment may present with radiating pain(3). Notably, the PIN has no cutaneous innervation.
Radial Tunnel
The radial tunnel consists of four boundaries and extends from the head of the radius, anterior to the radiocapitellar joint, to the distal border of the supinator muscle, measuring approximately five centimeters in length (see table and figure 1).
Our international team of qualified experts (see above) spend hours poring over scores of technical journals and medical papers that even the most interested professionals don't have time to read.
For 17 years, we've helped hard-working physiotherapists and sports professionals like you, overwhelmed by the vast amount of new research, bring science to their treatment. Sports Injury Bulletin is the ideal resource for practitioners too busy to cull through all the monthly journals to find meaningful and applicable studies.
*includes 3 coaching manuals
Get Inspired
All the latest techniques and approaches
Sports Injury Bulletin brings together a worldwide panel of experts – including physiotherapists, doctors, researchers and sports scientists. Together we deliver everything you need to help your clients avoid – or recover as quickly as possible from – injuries.
We strip away the scientific jargon and deliver you easy-to-follow training exercises, nutrition tips, psychological strategies and recovery programmes and exercises in plain English.