Elbow pain glossary: 36 terms in plain English

Anatomy

Lateral epicondyle

The bony bump on the outer side of the elbow, at the end of the humerus. The wrist and finger extensor muscles anchor here, which is why outer-elbow pain flares with gripping and wrist extension.

Medial epicondyle

The bony bump on the inner side of the elbow. Anchor point for the wrist flexors and pronators; the site of golfer's elbow.

ECRB (extensor carpi radialis brevis)

The forearm muscle whose tendon origin degenerates in most tennis elbow cases. It extends the wrist and, crucially, stabilises it every time you grip, so a firm handshake can hurt even though no "tennis" is involved.

Common extensor origin

The shared attachment of several extensor muscles on the lateral epicondyle. Tendinopathy here is rarely one neat tendon; it's a junction under collective load.

Common flexor origin

The mirror structure on the medial side: shared attachment of the wrist flexors and pronator teres. Overloaded by gripping with wrist flexion, throwing, and pull-up volume.

Pronation / supination

Forearm rotation: pronation turns the palm down, supination turns it up. Weak or painful rotation is common in elbow tendinopathy and gets its own rehab drills.

Ulnar nerve

The nerve running in a groove behind the medial epicondyle (the "funny bone"). Tingling in the ring and little fingers points at this nerve, not at a tendon, and changes the treatment plan entirely.

Conditions

Lateral epicondylitis (tennis elbow)

Degenerative tendinopathy of the common extensor origin, ICD-10 M77.1. Only about 5% of cases come from tennis; most come from repetitive gripping and wrist extension at work or in the gym. Full picture in symptoms and diagnosis.

Medial epicondylitis (golfer's elbow)

The medial-side equivalent, ICD-10 M77.0, affecting the flexor-pronator origin. Roughly 3 to 5 times rarer than tennis elbow. Differences explained in tennis elbow vs golf elbow.

Tendinopathy

Umbrella term for a painful, load-intolerant tendon, no claim about inflammation included. This is the term modern clinicians prefer for chronic tendon pain.

Tendinitis

Tendon pain driven by acute inflammation ("-itis"). Histology studies show chronic tennis and golf elbow tissue mostly lacks inflammatory cells, which is why the "-itis" label is fading and why anti-inflammatories alone rarely fix it.

Tendinosis

The degenerative tissue state itself: disorganised collagen, increased ground substance, ingrown vessels and nerves. What a chronic case looks like under a microscope.

Radial tunnel syndrome

Compression of the radial nerve a few centimetres below the lateral epicondyle. The great tennis elbow impostor: similar pain location, but more aching, more diffuse, and worse with resisted supination. One of the differentials in other causes of elbow pain.

Cubital tunnel syndrome

Ulnar nerve compression behind the medial epicondyle. Inner-elbow ache plus tingling in the ring and little fingers, often worse with a bent elbow (phone calls, sleeping).

Irritability

How easily symptoms flare and how long they take to settle. High irritability means small loads cause long flares; rehab dosing is set by irritability, not by the calendar.

Loading & rehab

Eccentric contraction

The muscle produces force while lengthening, lowering a dumbbell, or slowly releasing a twisted FlexBar. The loading style with the longest track record in tendon rehab.

Concentric contraction

The muscle produces force while shortening, the lifting half of a rep.

Isometric contraction

Force at constant length, like squeezing a ball and holding. Used early in rehab because holds of 30 to 45 seconds often reduce tendon pain for a few hours.

Heavy slow resistance (HSR)

Relatively heavy load moved on a strict slow tempo, typically 3 seconds down and 3 up. Matches eccentric-only programs in trials and is easier to dose. The backbone of our home rehab protocol.

Tempo

The speed prescription of a rep, written like 3-0-1: 3 seconds lowering, no pause, 1 second lifting. In tendon work the first number is the one that matters.

Time under tension

Total seconds a muscle-tendon unit works per set. Tendon adaptation tracks time under tension better than rep counts, which is why tempo is prescribed at all.

Progressive overload

Increasing load gradually as tissue tolerance improves. In rehab the progression criterion is symptom response (no flare at 24 h), not ambition.

Load tolerance

How much mechanical stress the tendon can currently take without flaring. The whole point of a loading program is to push this ceiling up, week by week.

Traffic-light calibration

Daily symptom check that sets the session dose: green (0–3/10 stiffness) full session, amber (4–5) reduced load, red (6+) active recovery only. How the Tennis Elbow Oracle app decides your day.

24-hour rule

Judge a session by symptoms the next day, not during. A pain rise of more than 2 points that persists at 24 hours means the dose was too high; drop roughly 10% next session.

Deload

A planned reduction in training load, usually around 10 to 20%, after a flare or a plateau, to let tolerance catch up without stopping entirely.

Return-to-play criteria

Objective gates before resuming sport: pain-free full-effort grip, pain-free resisted wrist extension, and a full sport-simulation session without flare. Timeline context in the recovery timeline.

Central sensitisation

The nervous system amplifying pain signals after long-standing symptoms, so pain stops being a clean measure of tissue damage. One reason chronic cases (over 6 months) rehab on slower, less pain-reactive plans.

Treatments & gear

Tyler Twist

Eccentric wrist extensor exercise using a TheraBand FlexBar: twist with the healthy hand, release slowly with the injured one. Validated in a 2010 RCT. Full technique in the Tyler Twist guide.

FlexBar

A ridged rubber bar in four color-coded resistances (yellow, red, green, blue) used for the Tyler Twist and its golfer's elbow mirror, the reverse Tyler Twist.

Counterforce brace

A strap worn over the forearm muscle belly, a few centimetres below the elbow, that redistributes force away from the painful origin during activity. Useful symptom management; does not heal the tendon. Compared against sleeves and taping in braces, taping and sleeves.

Corticosteroid injection

Steroid injected at the tendon origin. Strong short-term relief, but multiple trials show worse outcomes than exercise or even wait-and-see at 6 to 12 months, plus higher recurrence. Trade-offs in treatment options.

PRP (platelet-rich plasma)

Concentrated platelets from your own blood injected into the tendon to stimulate repair. Evidence for elbow tendinopathy is mixed and it is rarely a first-line option. Head-to-head numbers in PRP vs eccentric exercise.

ESWT (shockwave therapy)

Acoustic pulses applied over the tendon, typically 3 to 5 sessions, used when a well-run loading program stalls. Moderate-quality evidence, results vary.

Dry needling

Fine needles inserted into the tendon or surrounding muscle without injecting anything, intended to provoke a local healing response. Evidence is limited; usually an adjunct, not a plan.

Overgrip

A thin wrap applied over a racket handle, adding about 1/16 inch (half a grip size). The cheap fix for a slightly undersized grip; see the grip size calculator.

Scores & measures

VAS / NRS pain score

The 0-to-10 pain rating. Crude but useful: rehab decisions key off it (keep sets at or under 4/10, flag a 24-hour rise of more than 2 points).

PRTEE

Patient-Rated Tennis Elbow Evaluation: a 15-item questionnaire scoring pain and function from 0 to 100. The standard outcome measure in tennis elbow trials.

DASH / QuickDASH

Disabilities of the Arm, Shoulder and Hand: a broader upper-limb function score, often quoted in studies (the Tyler Twist trial used it).

Grip dynamometer

The squeeze-measuring device behind "pain-free grip strength", the most practical objective tracker for elbow tendinopathy. A side-to-side difference over 10 to 15% is meaningful.

ICD-10 codes M77.0 / M77.1

The classification codes on your paperwork: M77.0 is medial epicondylitis, M77.1 is lateral. Handy when reading reports or insurance letters.

Definitions follow NICE Clinical Knowledge Summaries (tennis elbow), AAOS OrthoInfo patient material, and the ICON 2019 tendinopathy terminology consensus (Scott et al., Br J Sports Med 2020). Last verified 13 June 2026.