The Hand and Wrist
Extrinsic wrist and finger extensors and intrinsic hand muscles
Most of the muscles that move the fingers are located in the forearm, hence their name : the extrinsic (outside) muscles of the hand. On the inside of your arm the flexors pull your fingers down onto the strings while, on the back of your arm, the extensors lift them away from the neck. These movements are elemental for every guitar player and much of the program deals with making them as efficient as possible.
The muscles in the hand itself allow our movements their precision and guitarists rely heavily on them. Placing your fingers on and off the fretboard is one thing but these intrinsic muscles point your fingers to the right place. Cramping is common in the hand and is inevitable when playing through the eventual fatigue that these muscles suffer when they are not used properly.
These two groups work together, the extrinsic muscles, apart from the thumb, provide nearly all of the force and the intrinsic muscles control the finer movements. If however one group doesn't do it's job then the other will be called on to compensate. The main problem relates to the position of the wrist, reducing the efficiency of the extrinsic muscles, making the smaller intrinsic muscles work harder.
The position of the wrist will affect the resting length of the muscles that control the hand.
The extrinsic hand muscles cross the wrist and at least one knuckle before attaching onto a finger. If the wrist is in a neutral position they can rest at their normal length. When you change the position of the wrist then the muscles that run up onto the fingers will have to change length as well, even if their not actually doing anything.
Due to phenomena called passive and active insufficiency muscles work better at an optimum length, it has to do with how the filaments in muscle fibres slide across each other to make them shorten. The further from that optimum length these muscles are taken due to the position of the wrist, the more work they’ll have to do for the same simple tasks that would be a breeze with the wrist neutral.
For example
You’re playing a barre chord and require pressure on the strings with the fingers of your left hand. The finger flexors, on the inside of your forearm provide the energy to do this. If you’re wrist is fully flexed then these muscles are already short and then you're asking them to shorten further to barre the chord. This is hard work and causes the muscle to fatigue earlier, increasing the tension in the arm and hand and the likelihood of cramp and overuse injuries.
By getting as close to possible to a neutral wrist position you can produce the same force with significantly less effort.
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With your wrist neutral close your fist - easy.
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Now flex your wrist as far as it will go and try to close your fist again.
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Fully extend your wrist and try to straighten your fingers - I told you.
The Structural Anatomy of the Hand
The fingers comprise of three long bones called phalanges while the thumb has just two. Each of the four fingers and the thumb attach to a corresponding metacarpal, long bones that form the body of the hand.
The joints where these bones articulate are named according to these bones. So we have metacarpophalangeal joints between the metacarpals and phalanges and interphalangeal joints, distal and proximal, between the phalanges. The five metacarpals connect with the wrist at the carpometacarpal joints.
Apart from the thumb, which has a wide range of motion, flexion and extension is the main movement of all of the joints in the hand. The range of flexion increases from radius to ulna so the little finger has more than the first.
The fingers are also able to adduct and abduct, allowing us to spread the fingers. It occurs mainly at the metacarpophalangeal joints (so the fingers move but the metacarpals don't) although the metacarpal of the little finger is also capable of lateral movement. When the wrist or fingers are flexed this lateral movement is restricted.
The Functional Anatomy of the Hand
Muscles that articulate the hand
Two groups of muscles articulate the hand. Muscles that originate on the arm and cross the wrist are called extrinsic muscles while those that originate on the hand itself are called intrinsic muscles.
Extrinsic muscles of the hand
It's not as complicated as it may look.
- Flexors are on the inside of the forearm and extensors are on the back.
- The larger extrinsic muscles branch in the hand to connect to all four fingers. Individual fibres within the muscle control particular fingers.
- Two muscles flex the fingers. A deep one connects to the end of each finger, it does most of the work and acts on the whole finger. A more superficial one connects to the base of each finger and helps out when the wrist is flexed or when you don't need to flex the whole finger.
- Only one extrinsic muscle flexes the thumb
- There is only one main muscle that extends the fingers, it attaches on the middle bone of the finger and to the end of the finger via a mechanism of tendons. Two other extensors attach to the index and little fingers giving them greater independance.
- Three muscles extend the thumb at different points, one of them is also an abductor.
|
Muscle
|
Location
|
Action
|
| Flexor digitorum superficialis |
On the inside of the forearm, attaches to the base of the finger (proximal phalanx) |
Flexes the fingers, does not act on the distal joint |
| Flexor digitorum profundus |
On the inside of the forearm, attaches closer to the tip of the finger (on the distal phalanx) |
Flexes the fingers, including the distal joint |
| Flexor pollicis longus |
On the inside of the forearm, attaches to the distal phalanx of the thumb |
Flexes the thumb |
| Extensor digitorum |
On the back (dorsal surface) of the forearm, from the elbow (on the lateral epicondyle) to the back of the middle phalanx |
Extends the fingers, an extensor mechanism attaches to the distal phalanx ensuring that both joints of the finger extend together |
| Extensor indicis |
On the back of the forearm from the ulna to the extensor digitorum tendon on the index finger |
Allows more independant extension of the index finger |
| Extensor digiti minimi |
At the back of the forearm from the lateral epicondyle to the tendon of the extensor digitorum |
Allows more independant extension of the little finger |
| Extensor pollicis longus |
On the radial side of the back of the forearm connecting on to the distal phalanx of the thumb |
Extends the thumb |
| Extensor pollicis brevis |
On the radial side of the back of the forearm to the proximal phalanx of the thumb |
Extends the thumb |
| Abductor pollicis longus |
On the radial side of the back of the forearm to the base of the first metacarpal |
Extends and abducts the thumb. |
Intrinsic muscles of the hand
The interossei lie on either side of the hand between the metacarpals and the lumbricals are on the palmar side between the deep flexor tendons of the fingers. Their primary function is in adduction/abduction of the fingers and to contribute to fine motor control.
- Adduction and abduction of the fingers. Positioned between the metacarpals they attach onto the proximal phalanges enabling them to spread the fingers.
- Assisting in flexion and extension of the fingers. Because they lie in between the metacarpals the position of the fingers, as determined by the extrinsic muscles will sometimes put them closer to the front (making them flexors) and sometimes closer to the back of the hand (making them extensors).
- Acting as synergists to control the finer positioning of the fingers. For example your fretting hand is sometimes extended at the first knuckle (metacarpophalangeal joint) while the fingers themselves are flexed. In this position the larger extrinsic flexors and extensors compete with each other, passive tension in the interossei helps you do this with a greater degree of control.
The other intrinsic hand muscles control the thumb and the little finger, allowing the hand to close in and grip objects. Look at your hand and you'll see two fleshy pads at the base of the palm. On the thumb side (the thenar eminence) are the three thumb muscles, there are three more on the ulnar side controlling the little finger and one in the middle.
| Muscle |
Location |
Action |
| Abductor pollicis brevis |
From the carpals to the first phalange of the thumb (on the thenar eminence) |
Abduct and assist in opposition of the thumb |
| Opponens pollicis |
From the lateral wrist to the first metacarpal (on the thenar eminence) |
Opposition of the thumb |
| Adductor pollicis |
From the centre of the hand to the thumb (also on the thenar eminence) |
Adduction of the thumb |
| Palmaris brevis |
In the palm of the hand |
Assist in closing the palm of the hand |
| Abductor digiti minimi |
On the ulnar side of the hand from the medial carpals to the first phalange of the little finger |
Abduction of the little finger |
| Flexor digiti minimi brevis |
On the ulnar side of the hand attaching on the medial carpals just inside the abductor attachment to the first phalange of the little finger |
Flexion of the little finger |
| Opponens digiti minimi |
Attaching just inside the flexor to insert onto the outside of the fifth metacarpal |
Opposition of the little finger (roll it in to the middle) |
Hand biomechanics for guitar players
The following descriptions are meant to explain the biomechanics of the hand, not to infer a preference for one style or technique over another. Any suggestions are purely in the context of reducing the tension in the hand, if you can live with a certain amount of tension, and we all can, then whatever works for you is great. If it's not working however......
The left hand
Opposition of the thumb is required to place it behind the neck of the guitar. It is accomplished by abductor pollicis longus (see De Quervains tenosynovitis), palmaris brevis and the three muscles on the thenar eminence. In combination they flex, adduct and medially rotate the thumb, bringing it to the hand, or in our case to the back of the guitar.
Placing the fingers on and off the strings is accomplished by the flexors and extensors and moderated by the intrinsic hand muscles. In the example here the flexors (red line) are contracting to pull the finger down on to the fret. The extensors (blue line) have to stretch to allow this to happen. When you extend your finger to take it off the fretboard the opposite happens.
As we've seen with our discussion of the wrist the extrinsic hand muscles will have to work overtime when the wrist is not in a neutral position. This in turn adds to the load of the smaller intrinsic muscles causing fatigue and cramp.
Flexion of the metacarpo-phalangeal joint (the large knuckle at the base of the finger) brings the fingers in toward the hand, or in our case to the fretboard. It also increases the force needed by the interossei to abduct (seperate) the fingers. Again this extra energy requirement will lead to fatigue in the hand and eventually cramping.
The right hand
Fingerpickers obviously face different challenges to flatpickers. Everyone though, particularly for right hand technique, needs to have soft relaxed hands, we know this already. Just focusing on relaxing your hands is not enough though. They need to be in a comfortable position and for this to happen your whole body needs to be relaxed, your shoulders should be soft and in the right position to get the arm at a good angle to approach the guitar properly.
Then there's the problem of knowing how to relax in the first place, if it were that easy we'd all be doing it. This is why the relaxation techniques in the program are graded, it's the best way to learn what is for some, a challenging task.
Flatpicking
Holding the flatpick between the thumb and first finger requires opposition of the thumb and flexion of the first finger, providing you don't hold it too tightly this should be a comfortable position and not cause any problems. Picking the strings requires, to various degrees, lateral deviation, supination and pronation of the wrist and flexion and extension of both the first finger and the thumb. Strumming chords will also involve flexion and extension of the elbow if you are leaning over a thin guitar close to your body, but more often rotation of a flexed shoulder.
Resting the wrist on the bridge creates tension in the extensors of the dorsal forearm as well as restricting access to the strings. Your hand will relax considerably more once you get it off the guitar completely.
Fingerpicking
Fingerpickers need to deviate their wrist to the ulna side in order to orient the knuckles parallel with the strings. The movement of the fingers is not dissimilar to the left hand although there shouldn't be any abduction and less force is required because we're not pushing into the fretboard.
The same principles apply as here as they did for the left hand, in order for the intrinsic hand muscles to work best the larger ones need to be relaxed. A gentle curve rather than a claw in the right hand will reduce the tension in the extrinsic flexors and therefore the intrinsic muscles as well. I'm positioned for pattern picking here so my index finger is up on the G string which makes it claw more than it would if I was playing melodic lines more like a classical player.
To avoid wrist flexion the thumb picks the bottom strings by adducting and abducting up and down roughly parallel to the strings, depending on the guitar.
The Structural Anatomy of the Wrist
The wrist is comprised of two rows of small irregular shaped bones called carpals that articulate with each other as if they were two individual units. The proximal row also articulates with the forearm (the radius and the radioulnar disk) at the radiocarpal joint while the distal row articulates with long bones in the hand (the metacarpals). Within each of the rows much smaller movements can occur between individual carpals.
The range of motion at the wrist is limited by the shape of these articulating bones. They don't fit together too well. Flexion and extension of the wrist require the two rows slide across each other, eventually locking up due to tension in the connecting ligaments and the individual bones contacting each other.
Flexion of the wrist involves bringing the palm toward the inside of the forearm, like when your fingerpicking. The maximum range is about 85˚. The opposite movement, extension has a range of between 70˚ and 80˚. It can also move from side to side, radial deviation, or movement to the side the thumb is on is about 20˚ to 25˚while ulnar deviation is between 30˚ and 35˚.
The main function of the wrist is to adjust the tension in the muscles that control the hand and fingers. Because they cross the wrist their length and therefore the passive tension in the connective tissue will change as the wrist moves.
The Functional Anatomy of the Wrist
Muscles that articulate the wrist
The muscles that articulate the wrist can be broadly grouped according to their action. The flexors originate on the medial epicondyle of the humerus, traverse the inside of the forearm and connect on the carpals of the wrist, the metacarpals of the hand or the phalanges of the fingers and thumb. The extensors originate on the lateral epicondyle of the humerus, run down the back of the forearm and again attach on the carpals, metacarpals or phalanges.
|
flexors |
extensors |
| location |
volar aspect (inside) of forearm |
dorsal aspect of forearm |
| origin |
medial epicondyle of the humerus |
lateral epicondyle of the humerus |
| wrist |
palmaris longus, flexor carpi radialis, flexor carpi ulnaris |
extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris |
| fingers |
flexor digitorum superficialis, flexor digitorum profundus |
extensor digitorum, extensor indicis, extensor digiti minimi |
| thumb |
flexor pollicis longus |
extensor pollicis longus, extensor pollicis brevis, abductor pollicis longus |
So while the flexors flex and the extensors extend these aren't the only movements available at the wrist. Lateral deviation toward the ulna (the little finger) is possible when both flexor and extensor on the ulnar side (flexor carpi ulnaris and extensor carpi ulnaris) contract together. Lateral deviation toward the radius involves both flexor and extensor on the radial side although extensor carpi radialis muscles do most of the work. Two muscles that control the thumb: abductor pollicis longus and extensor pollicis brevis are also active in radial deviation of the wrist but to a lesser degree.
The wrist muscles also act to stabilise the wrist when the hand is moving or grasping objects. Because the finger flexors for example cross the wrist their contraction should cause the wrist to flex as well. The reason that this doesn't automatically happen is that wrist extensors produce a force in the opposite direction cancelling out any movement of the wrist. This has implications for our playing given the amount of movement that the fingers have to do.
Wrist biomechanics for guitar players
Apart from contributing to the position of the hand the primary function of the wrist that has relevance for us is its role in adjusting the tension in the extrinsic muscles of the hand. The wrist flexors and extensors described previously insert onto the carpal bones, parallel to these the extrinsic hand muscles cross the wrist and continue onto the fingers.
Holding your wrist in a fixed position, say fully flexed, will cause the finger flexors to shorten and the extensors to lengthen. Having to work from this position causes a few problems. The flexors are already shortened because of the position of the wrist so asking them to shorten further uses more energy than it would otherwise (a phenomenon called active insufficiency) causing muscles to fatigue and eventually cramp.
Exercise
- Holding your wrist straight make a fist with your hand, shouldn't be a problem.
- Now flex your wrist and try to do the same thing.
Common wrist positions
It is not difficult to achieve a neutral wrist position on either side once the basic posture and shoulder positions are sorted. Having said that there are a number of common presentations that will always increase tension in the hand.
Flexion of the left wrist
If you tilt your guitar back to see the fretboard you're forced to reach around like this with your left hand. This shortens the flexors of the wrist and the fingers and adds considerably to the tension in the arm and hand.
If you're standing and have the guitar low on a long strap you'll also have to do this when playing barre chords. This will be a real problem if you're a rhythm player in a rock band.
Extension of the left wrist
This thumb position will cause wrist extension when the guitar is high on a strap or if you're sitting. This position creates significant passive tension (stretch) in the muscles that abduct and extend the thumb (blue line) and active tension in the finger extensors (red line).
Resting the right wrist on the bridge
This position is more problematic for acoustic players, increasing tension in the dorsal forearm extensors. The wrist looks straight here but as you can see the back of the hand is pulled up away from the wrist in an extended position. Muscles that attach here have to shorten to maintain this position. It's the same dynamic as when you hold a mouse (your computers mouse) or use a trackpad incorrectly.
It's less of a problem for electric players, the thinner body and the lower positioning allow for a more neutral wrist.
Common injuries of the wrist and hand
For most guitarists the main problem with the hand will be fatigue and the inevitable cramping that follows when we play through it. The left hand tends to suffer more because pressing onto the fretboard requires more work from the muscle.
The main causes are related to technique, excess tension in the hand and simply playing too much. The most immediate problem is that your playing is severely restricted, there is no way you can play your instrument fluently if there is excess myofascial tension in your hand, arm or shoulder.
Tension, or hypertrophy, in the muscles of the wrist and hand can, over time, lead to more serious medical conditions. I've listed a few of them below that are typical of Occupational Overuse Syndromes affecting the hand and wrist along with their Wikipedia links. Check out the links page and our friend Google for more information on them. Keep in touch here as well I'm always looking at the latest research and I'll keep you posted.
The biomechanics studies of the wrist and hand are worth investigating as are the relevant sections of the premium content.
Cumulative Trauma Disorders of the wrist and hand
