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Forearm and grip
Two groups of muscles that move the wrist and fingers from a distance, and the reason grip strength tracks so much else.
Latin name: Musculi antebrachii. In plain English, the muscles below the elbow that close your hand. It is filed here under arm and forearm.
Reference information, not a diagnosis. Where a symptom is described below, it is there so you can describe your own more precisely to a clinician — not so you can name what you have.
Where it is
The muscles that close your fist are not in your hand. They sit in the forearm and act on the fingers through long tendons that run under the retinaculum at the wrist — an arrangement that keeps the hand light and mobile while the power comes from further back. The flexors form the soft front of the forearm and arise from a common tendon on the inner bony bump of the elbow; the extensors form the firmer back and arise from the outer bump.
This shared origin explains the two famous elbow problems. Repeated loading of the extensor tendons irritates their attachment at the lateral epicondyle — tennis elbow. The same story on the flexor side at the medial epicondyle is golfer's elbow. Neither is usually caused by the named sport, and both are tendon-loading problems rather than inflammation in the classic sense.
| Feature | Detail |
|---|---|
| Flexor group | Common flexor origin on the medial epicondyle of the humerus; bends the wrist and fingers; median nerve mostly, with the ulnar nerve supplying flexor carpi ulnaris and part of flexor digitorum profundus |
| Extensor group | Common extensor origin on the lateral epicondyle; straightens the wrist and fingers; radial nerve and its posterior interosseous branch |
| Nerve | Median, ulnar and radial nerves (C5-T1) |
| Main actions | Flexion and extension of the wrist and fingers, deviation of the wrist, and pronation and supination of the forearm |
What it does
Grip has two components that behave differently. Crushing grip closes the fingers into the palm and comes mostly from the deep and superficial finger flexors. Support grip — hanging from a bar, carrying shopping — is largely an endurance task, and it is the one that fails first in daily life. The extensors work at the same time in both, holding the wrist steady so the flexors have something to pull against; try gripping hard with the wrist fully bent and you will feel how much strength disappears.
Grip strength is measured clinically for a reason: it is quick, cheap and it correlates with general muscle strength and with function in older adults. It is a proxy, not a cause — squeezing a rubber ball does not buy the health that grip strength is associated with — but it is a genuinely useful number, and it is one of the few strength measures with published age and sex reference values.
Exercises that load it
| Exercise | Category | Muscles the exercise library lists |
|---|---|---|
| Pull-ups | Strength | Lats, biceps, mid-back, grip |
| Deadlift | Strength | Hamstrings, glutes, back, grip |
| Farmer's carry | Strength | Grip, core, upper back, legs |
| Bent-over row | Strength | Mid-back, lats, biceps |
| Kettlebell swing | Conditioning | Glutes, hamstrings, back, core |
Carrying is the best grip training there is, because it loads the support grip for time under a heavy load with no technique to learn. Deadlifts and rows load it heavily but briefly. Pull-ups and hangs load it at full stretch. If grip is what limits your pulling, the answer is usually more carrying and hanging rather than a gadget — though straps have their place for the sets where the back, not the hands, is the target.
How it is lengthened
With the elbow straight and the palm facing forward, use the other hand to draw the fingers gently back to lengthen the flexors, then turn the palm down and draw the hand downward to lengthen the extensors. Both should feel like a broad pull along the forearm, never a sharp pain at the elbow. If the bony bump at the elbow is the sore point, stretching into it is not the answer and it is worth having assessed.
When it goes wrong
| Problem | What it typically feels like | Usual setting |
|---|---|---|
| Lateral epicondyle pain (tennis elbow) | Pain on the outer bump of the elbow when gripping, lifting a cup or shaking hands | Repetitive gripping and wrist extension at work or in sport, often after a change in load |
| Medial epicondyle pain (golfer's elbow) | Pain on the inner bump of the elbow when gripping or bending the wrist against resistance | Repeated heavy gripping, throwing, or a sharp increase in pulling volume |
| Carpal tunnel syndrome | Numbness and tingling in the thumb, index and middle fingers, classically waking you at night | Median nerve compression at the wrist; associated with pregnancy, thyroid disease and diabetes as well as with hand use |
| De Quervain tenosynovitis | Pain at the thumb side of the wrist when gripping or lifting with the thumb out | Repeated thumb and wrist loading, commonly seen when lifting a small child |
Numbness or weakness in the hand that persists, wakes you at night, or wastes the muscle at the base of the thumb should be examined. Nerve problems that are left alone for a long time recover less well.
Nothing on this page is a treatment plan. If a problem is limiting what you do, is not improving, or is getting worse, the right next step is an assessment by a doctor or a physiotherapist who can examine you.
Sources: descriptive anatomy from Gray's Anatomy of the Human Body, 20th US edition (1918), which is in the public domain; Latin names follow Terminologia Anatomica, published by the Federative International Programme for Anatomical Terminology. Nerve root levels are the conventional ranges taught from those sources and vary between individuals and between textbooks. Exercise cross-links use the TempoLife exercise library. Checked 2026-09-06.
Frequently asked questions
Why does grip strength matter for health?
It is a simple, repeatable measure of whole-body muscle strength, and in large studies it tracks with physical function in later life. It is best read as a marker of overall strength and activity rather than as something to train in isolation.
Does tennis elbow come from playing tennis?
Usually not. Most people with it have never played. Any repeated gripping-and-extending task can produce it — a new job, a lot of DIY, a sudden increase in training volume.
Can I train grip every day?
The forearms recover quickly, but tendons at the elbow do not always agree. If the elbow attachments start to complain, that is the signal to reduce frequency rather than to push on.
Nearby in this reference
Biceps brachii
The two-headed muscle at the front of the upper arm
Triceps brachii
The three-headed muscle at the back of the upper arm
Deltoid
The cap of the shoulder
Rotator cuff
The four small muscles that hold the shoulder in its socket
Trapezius
The big diamond across the upper back and neck
Rhomboids
The straps that pull the shoulder blades together
All 34 body parts · Exercise library · Body map
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