The wrist and hand: 27 bones, the carpal tunnel, the thumb and your grip

27 bones in each hand

The usual count is 8 wrist bones (carpals) in two rows, 5 palm bones (metacarpals) and 14 finger bones (phalanges): two in the thumb and three in each finger. Small sesamoid bones at the knuckles aren't part of the count.

Sources 1, 2

The wrist joint and the carpal tunnel

The wrist joint is between the radius and three wrist bones; the ulna isn't part of it. At the front of the wrist, the carpal bones and a tough band about 3 cm long form the carpal tunnel, which carries 9 tendons and the median nerve.

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The thumb's saddle joint

The joint at the base of the thumb is shaped like two saddles fitting together, so the thumb can move in two planes and turn to touch each fingertip (opposition).

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Grip starts in the forearm

In a power grip, one deep forearm muscle pulls all four fingers in together while the wrist extensors hold the wrist steady. The small muscles inside the hand fine-tune the fingers and add to pinch and grip strength.

Sources 7, 8, 9

Grip strength is a health marker, not a lever

Each 5 kg lower grip went with a 16% higher risk of death over about 4 years in 139,691 adults in 17 countries, and UK Biobank found the same in half a million people. That is an association: exercise raises grip a little, but no trial has tested whether that changes your risk.

Sources 10, 11, 12

Daily life uses part of the range

In a study of 40 adults, most daily tasks fitted within about 40 degrees of wrist bending each way, and in 24 adults the hand's joints stayed 5 to 28 degrees short of their full range during daily activities. Moving them fully takes deliberate practice.

Sources 13, 14

The bones

Each hand has 27 bones in the usual count. The 8 carpal bones sit in two rows: the scaphoid, lunate, triquetrum and pisiform nearest the forearm, and the trapezium, trapezoid, capitate and hamate nearest the hand. The capitate is the largest and most central, the trapezoid the smallest, and the scaphoid the one most often broken, at 60 to 70% of carpal fractures. The hook of the hamate protects the ulnar nerve and artery in a passage called Guyon's canal.

Beyond them are 5 metacarpals in the palm and 14 phalanges: two in the thumb and three in each finger. A pair of small sesamoid bones sits at the thumb's knuckle, and single ones appear over the index and little-finger knuckles in about 60% of people; they aren't part of the usual count. The bones form three arches, one along the hand and two across it, which help it cup and grip.

Sources 1, 2, 15

The joints

From the forearm to the fingertips:

• Wrist (radiocarpal) joint: a condyloid joint between the radius, with a cartilage disc beside it, and the scaphoid, lunate and triquetrum. The ulna isn't part of the wrist joint itself.
• Joints between the carpal bones: small gliding (plane) joints that add to wrist movement.
• Distal radioulnar joint: the pivot at the wrist where the radius turns around the ulna as the forearm rotates.
• Thumb base (carpometacarpal) joint: a saddle joint between the trapezium and the first metacarpal.
• Finger knuckles (metacarpophalangeal joints): they bend, straighten, spread and close; one reference calls them condyloid, another a shallow ball and socket.
• Thumb knuckle: a hinge that bends up to 80 to 90 degrees, with little movement in other directions.
• Finger and thumb joints (interphalangeal joints): hinges that bend and straighten.

Sources 3, 5, 16, 17

Ligaments and the TFCC

The palmar radiocarpal ligaments, at the front, are the wrist's strongest supports, helped by ligaments at the back and on each side. On the little-finger side, the triangular fibrocartilage complex (TFCC), a cushion of cartilage and ligament, is the main stabiliser of the distal radioulnar joint and also carries load.

Sources 3, 18

The carpal tunnel

The carpal tunnel is a passage at the front of the wrist. Its floor is the arch of the carpal bones, and its roof is the flexor retinaculum, a band about 3 cm long and 2.5 cm wide that thickens from 1.5 to 6 mm, anchored to the scaphoid and trapezium on the thumb side and the pisiform and hook of the hamate on the little-finger side.

Through it run 9 tendons, the 4 superficial and 4 deep finger flexors and the long flexor of the thumb, with the median nerve. Raised pressure in the tunnel squeezes the nerve: carpal tunnel syndrome has a reported rate of 1 to 5% in the general population, is three times as common in women as in men, and usually starts at 40 to 60.

Sources 4, 19

The thumb and opposition

The thumb's base is a saddle joint: the surfaces are concave one way and convex the other, so the thumb can bend and straighten alongside the palm and move away from and towards it, which makes it opposable. Opposition, the thumb tip meeting a fingertip, combines bending, turning inward and moving away from the palm, driven mainly by the opponens pollicis, one of three thenar muscles at the base of the thumb.

Sources 5, 6, 9

How grip works

In a power grip, the deep finger flexor (flexor digitorum profundus), a forearm muscle with a tendon to each finger, pulls all four fingers in together. The wrist extensors hold the wrist in slight extension so the flexors can produce their full force, which is why gripping loads the tendons at the outer elbow.

Fine movements, such as typing, rely more on the small muscles inside the hand: the lumbricals are essential for precision grip and fine control, and the intrinsic muscles together add to pinch and grip strength.

Sources 7, 8, 20, 9

The nerves

The median nerve gives feeling to the palm side of the thumb, index, middle and half of the ring finger, and powers the three thenar muscles and two of the lumbricals. The ulnar nerve gives feeling to the little finger and the other half of the ring finger, and powers most of the small muscles inside the hand. The radial nerve gives feeling to the rest of the back of the hand.

Sources 1, 9

The wrist's four movements

The wrist bends forward (flexion) and back (extension) and tilts towards the thumb (radial deviation) and the little finger (ulnar deviation). In a study of 30 adults aged 23 to 30, the reported averages ranged from about 62 to 80 degrees for forward bending, 65 to 70 for bending back, 15 to 25 for tilting towards the thumb and 33 to 45 for tilting towards the little finger, depending on sex, hand and how the forearm was turned.

Source 21

What daily tasks need

In a 1991 study of 40 adults, most tasks could be done with about 40 degrees of bending each way and 40 degrees of side-to-side tilt, and every task tested fitted within 60 degrees back, 54 forward, 40 towards the little finger and 17 towards the thumb. A smaller 1985 study of 10 adults doing 52 tasks found smaller needs, so the figures depend on the tasks chosen.

Sources 13, 22

Fingers and thumb

The finger knuckles bend, straighten, spread and close, and the middle and end joints bend and straighten. In a small 1990 study of 11 daily activities, the fingers used only a small share of their range: on average about 61 degrees of bend at the knuckle, 60 at the middle joint and 39 at the end joint, and about 21 degrees at the thumb's knuckle, which can bend up to 80 to 90.

Sources 23, 17

Use it or lose it

In a study of 24 adults doing 24 daily activities, the hand's joints moved 5 to 28 degrees less than their full range, and the authors suggest daily activities alone may not keep or restore full range. Moving the wrist and fingers through their whole range on purpose fills the gap.

Source 14

Forearm position changes the wrist

In the same study of 30 young adults, wrist range changed with the forearm's position, and grip was weakest with the palm facing down, in both men and women.

Source 21

With age

We found no large study of wrist range by age that we could check. Range falls with age across the body's joints in general, while grip strength, which is well studied, peaks in early adult life and declines from midlife.

Sources 24, 25, 26

What's typical

Across 49,964 people in 12 British studies, grip strength rose to a peak in early adult life, held until midlife and then declined. The peak median was 51 kg in men aged 29 to 39 and 31 kg in women aged 26 to 42. By age 80, 23% of men and 27% of women had weak grip, defined as well below the average peak for their sex.

Source 26

What counts as low

The European consensus on sarcopenia, the loss of muscle strength and mass that is common with age, uses a grip under 27 kg for men and under 16 kg for women as low strength, based on the British data. UK Biobank used a similar cut-off for weakness: under 26 kg for men and 16 kg for women.

Sources 27, 11

Measuring it

Grip is measured with a handheld dynamometer, and the European consensus says accurate measurement needs a calibrated device under well-defined conditions. If you track your own grip, test it the same way each time: grip changes with forearm position, and was weakest palm down in one study.

Sources 27, 21

Weaker grip goes with a shorter lifeStrong evidence

In the PURE study (Prospective Urban Rural Epidemiology) of 139,691 adults aged 35 to 70 in 17 countries, followed for a median of 4 years, each 5 kg lower grip went with a 16% higher risk of death from any cause and 17% from heart and circulation disease, and grip predicted death better than systolic blood pressure. It wasn't linked with diabetes, falls injuries or fractures.

In 502,293 UK Biobank adults aged 40 to 69, followed for about 7 years, each 5 kg lower grip went with 20% higher death rates in women and 16% in men, with links to heart disease, lung disease and several cancers. Both are observational studies.

Sources 10, 11

Midlife grip predicts later disabilityEmerging evidence

In 6,089 healthy Japanese-American men aged 45 to 68, those in the weakest third of grip had nearly 3 times the odds of very slow walking 25 years later, and more than twice the risk of needing help with self-care, compared with the strongest third. It is one cohort, of men only.

Source 28

Grip reflects overall strengthStrong evidence

The European sarcopenia consensus says grip correlates moderately with strength elsewhere in the body, which is why it serves as a quick stand-in for arm and leg strength. A review calls it an indispensable biomarker for older adults, linked with function, falls, fractures, mood, cognition and death.

Sources 27, 29

Training grip to live longer: no evidence yetMixed evidence

No trial has tested whether raising grip strength lowers anyone's risk; the PURE authors call for research to test whether improving strength reduces deaths. Exercise of many kinds raised grip a little in older adults (24 trials, 3,018 people, average age 73), and the authors point to task-specific and multimodal training as a suitable stimulus.

Sources 10, 12

Exercise eases hand osteoarthritis a littleEmerging evidence

In a Cochrane review of 7 trials, hand exercise reduced pain by about half a point on a 0 to 10 scale, stiffness by about 0.7 points and improved function a little, on low-quality evidence. The benefits weren't sustained at 6 to 12 months.

Source 30

Hand exercises help rheumatoid handsStrong evidence

In a UK trial of 490 adults with rheumatoid arthritis of the hands, a tailored strengthening and stretching programme on top of usual care improved hand function more than usual care alone at 12 months (7.9 against 3.6 points), with no serious harms, at a cost of £156 a person. Our rheumatoid arthritis hand exercises follow the same approach.

Source 31

Move every joint, every day

Daily tasks don't take the hand's joints through their full range. Our editorial starting point: once or twice a day, take the wrist through all four directions and the fingers through tendon glides (the move's page gives 4 to 6 of each position, held for 5 seconds, the dose in an NHS hand-therapy leaflet).

Source 14

Train grip with the rest of your body

Train your grip for what it lets you do (carry shopping, open jars, hang from a bar) as part of whole-body strength training. Carries, hangs, wrist curls and squeezes all work it. Our editorial starting point: grip work 2 or 3 times a week, alongside your other strength training.

Sources 10, 12

Warm up before weight on your hands

Before push-ups, planks or yoga, warm the wrists through their range and build up time on your hands gradually. If your wrists ache only in those positions, our guide to wrist pain in push-ups covers changes of position (our advice).

With hand arthritis

Exercise helps a little with hand osteoarthritis and clearly helped rheumatoid hands in a large trial. Our hand arthritis guide and our rheumatoid arthritis hand exercises have the plans.

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Tingling in the thumb and first fingers, often at night

An aching pain that's worse at night, with tingling, numbness or pins and needles in the fingers, hand or arm, a weak thumb or difficulty gripping, can be carpal tunnel syndrome. Our carpal tunnel guide has the plan.

Source 32

Pain at the base of the thumb

Pain, swelling and stiffness near the base of the thumb that lasts a long time can be de Quervain's tenosynovitis (a tendon problem) or arthritis. Our de Quervain's and thumb arthritis guides cover both.

Source 32

Stiff, sore finger joints

Stiff, aching finger joints, sometimes with bony bumps, are often hand osteoarthritis; our hand arthritis guide covers it. Pain and stiffness on both sides of the body that's worse after rest, such as first thing in the morning, can be rheumatoid arthritis and needs a GP; our rheumatoid arthritis guide covers exercise for it.

Source 33

A finger that clicks or catches

Pain or tenderness in the palm at the base of a finger, with stiffness and clicking when you move it, can be trigger finger. Our trigger finger guide covers it.

Source 34

After a fall on an outstretched hand

Pain, swelling and bruising with a wrist that's hard to move or grip with can be a sprain, but a scaphoid fracture can be missed at first and mistaken for one. Pain at the base of the thumb after a fall needs checking; our wrist sprain guide explains.

Sources 32, 15

A smooth lump on the wrist

A smooth lump on top of the wrist, which may be painful, can be a ganglion cyst. Our wrist and hand pain guide covers ganglions and little-finger-side pain.

Source 32

Contact NHS 111 for the wrist

If you have severe wrist pain; you feel faint, dizzy or sick from the pain, or unwell, hot, cold or shivery; you heard a snap, grinding or popping noise at the time of the injury; you can't move your wrist or hold things; your wrist has changed shape or colour; you have a lump on your wrist that's very painful, hot or red; or you've lost the feeling in part or all of your hand. These might be signs of a broken wrist or an infection. In the US, contact your doctor or urgent care.

Source 32

Contact NHS 111 for a finger

If finger pain is severe, you feel faint, dizzy or sick from it, you heard a snap, grinding or popping noise at the time of the injury, you can't move the finger or hold things, it has changed shape or colour, you've lost feeling in part or all of your hand after an injury, or you also have a very high temperature or feel sick.

Source 34

See a GP

If wrist pain is stopping you doing normal activities, is getting worse or keeps coming back, or hasn't improved after 2 weeks of treating it at home; if you have any tingling or loss of feeling in your hand or wrist; if you have diabetes, because hand problems can be more serious; if you feel unwell with a high temperature; or if your wrist is painful, warm, swollen and stiff.

Source 32

After a fall on your hand

Pain and swelling at the base of the thumb after a fall needs checking even if the wrist still moves: a broken scaphoid is often missed at first and mistaken for a sprain.

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"The hand has 27 bones, and the wrist adds 8 more"Strong evidence

The usual count of 27 already includes the 8 wrist (carpal) bones, with 5 in the palm and 14 in the fingers and thumb. The radius and ulna belong to the forearm.

Sources 1, 2

"A strong grip makes you live longer, so train your grip"Mixed evidence

Grip predicts health, but no trial has shown that training it changes your risk. A strong grip is a sign of overall strength, so train it as part of whole-body strength training, for what it lets you do.

Sources 10, 12

"Cracking your fingers causes arthritis"Emerging evidence

In a 2011 case-control study of 215 adults with hand X-rays, people who cracked their knuckles had no more arthritis, however long or often they had done it, and a 2017 study with blinded examiners found no swelling and no loss of hand function or grip in crackers. None of the studies followed crackers forward for years.

Sources 35, 36

"Hand pain in push-ups means weak wrists, so push through"

Change the position first: our guide to wrist pain in push-ups covers fists or handles, leaning on a table or wall, and building up the weight through your hands gradually.