Hand weakness and impaired upper limb function in neurological conditions

Arm weakness means a partial loss of strength or movement control in the upper limb. It can involve the shoulder, upper arm, elbow, forearm, wrist, hand and fingers.

In one patient the most noticeable feature is an inability to lift the arm. In another the problem is a clenched hand. In yet another the arm moves, but it is imprecise, stiff, painful or, in practice, unused.

Weakness can be mild, moderate or severe. It can affect the entire limb or only selected functions, for example grip, straightening the fingers, rotating the forearm, stabilising the wrist or controlling the shoulder.

In rehabilitation the important question is not only: does the patient move their arm? The more important questions are: does the patient use the arm in everyday activities, can they open the hand, is there shoulder pain, can they feel touch and the position of the limb, is the arm free of spasticity, does the patient avoid compensating with the trunk, is the limb not being neglected, are contractures forming, can the patient exercise safely and does the family know how to help.

After a stroke, weakness of the upper limb is very common. It can affect the whole arm or selected functions: the shoulder, elbow, wrist, hand and fingers.

For many patients the arm is a greater problem than the leg. The patient may regain a steady gait and balance but still be unable to use the arm for eating, dressing, hygiene, writing or supporting themselves.

Typical problems after a stroke include: a limp arm, a clenched hand, an inability to straighten the fingers, no grip, stiffness, shoulder pain, a swollen hand, sensory disturbances, difficulty lifting the arm, a lack of scapular control, not using the arm in everyday life and a fear of moving the limb. How severe the arm deficit will be depends on which area of the brain was damaged.

In rehabilitation after a stroke it is very important not to judge the arm by strength alone. Sometimes the patient can move the fingers slightly but does not use the hand functionally. Sometimes they can raise the upper arm but do so by compensating with the trunk. Sometimes the arm does not move actively but urgently needs work on pain, positioning, range of movement and the prevention of contractures.

Well-run rehabilitation should address the whole upper limb, not just the hand. Arm movement begins in the trunk, the scapula and the shoulder. Without a stable trunk and proper control of the shoulder girdle, precise work of the hand can hardly be expected.

In some patients, spasticity develops over time after a stroke or other damage to the central nervous system. The arm begins to settle into a characteristic pattern: the shoulder and elbow are tense, the forearm and wrist take on an abnormal position, and the fingers clench into a fist.

For the family, the most visible feature is often the clenched hand. It makes washing, cutting the nails, putting on clothes, skin hygiene and using the arm more difficult.

Spasticity should not be stretched aggressively. Overly forceful movements can increase tone, pain and muscle resistance. What is needed is calm, systematic work on positioning, tone control, range of movement, activity of the antagonist muscles, function and everyday use of the arm.

In some cases a medical consultation on treating spasticity is also necessary, for example pharmacotherapy or botulinum toxin. Rehabilitation, however, is still needed, because reducing tone does not automatically restore function.

The arm can be weak, but it can also feel "foreign". The patient does not feel the hand well, does not recognise touch, does not know where the arm is without looking, cannot judge the strength of a grip or drops objects.

Sensory disturbances are often underrated, yet they matter greatly for function. A hand without normal sensation works imprecisely. The patient may crush a delicate object, drop a mug, fail to notice a burn or fail to control the position of the fingers.

In rehabilitation it is worth working on: sensory stimulation, recognising touch, distinguishing textures, controlling the position of the limb, visual-motor work, weight-bearing through the arm, contact of the hand with a surface and consciously involving the arm in tasks.

It is not just about "moving the arm". The brain has to learn again how to receive and use information from the limb.

In multiple sclerosis there is a great deal of talk about walking, but the arm and hand can also be seriously affected. The patient may have weakness, tremor, sensory disturbances, reduced precision, arm fatigue and difficulty with manual tasks.

Typical problems include: slower writing, dropping objects, difficulty doing up clothes, a weaker grip, intention tremor, the hand tiring quickly, difficulty working at a computer and reduced independence in the activities of daily living.

In MS it is important to tailor the amount of therapy to the individual. Not every patient should exercise equally intensively. Fatigue, temperature, current neurological status, relapses, recovery and functional capacity all need to be taken into account.

The aim of arm therapy in MS may be to improve function, maintain function, learn to conserve energy, organise activities better and prevent further loss of independence.

After a traumatic brain injury, impaired arm function can take various forms. It may result from weakness, spasticity, ataxia, sensory disturbances, problems with movement planning, attention disturbances, impulsivity or cognitive problems.

A patient after a brain injury may have strength in the arm but not use it effectively. They may perform a movement too abruptly, imprecisely or without control. They may also fail to notice their limitations and make risky attempts at activities on their own.

Rehabilitation should combine work on movement, sensation, coordination, safety, control of behaviour and function in everyday life.

Rehabilitation of the upper limb should begin with a thorough assessment. It is not enough to check whether the patient "will raise the arm".

You need to assess: trunk control, scapular positioning, shoulder movement, range of movement, pain, muscle tone, activity of the elbow, wrist and fingers, sensation, coordination, grip, the ability to open the hand, use of the arm in everyday activities, compensations, the risk of contractures and the patient's goals.

Only then can therapy be selected.

The healthy arm is needed, because the patient has to function. The problem arises when the whole of everyday life is shifted onto the healthy side alone, and the weakened arm gets no chance to take part in activity.

The point is not to forcibly restrain the healthy arm in every patient. The point is a sensible, gradual involvement of the affected arm wherever it is possible and safe. We describe this phenomenon in more detail in our article on the problem of the neglected arm after a stroke.

In selected patients, forms of constraint-induced movement therapy are used, but it is not a method for everyone. The patient must have an appropriate level of active movement, safety and control.

That depends on the cause, the extent of the damage, the time since onset, age, coexisting conditions, the degree of weakness, sensation, muscle tone, pain, the intensity of therapy and the everyday use of the arm.

After a stroke the fastest rate of improvement often occurs in the first few months, but rehabilitation can still be worthwhile later. This is especially true when the patient has retained partial movement but does not use the arm functionally, has pain, spasticity, restricted range or established compensations. We have devoted a separate article to the question of realistic timeframes: when arm function returns after a stroke.

In chronic and progressive conditions, such as MS or Parkinson's, the aim may be to improve function, maintain ability, reduce limitations, organise movement better and extend independence.

Not every patient will regain full arm function. But even partial improvement can significantly change everyday life: easier eating, dressing, hygiene, transfers, support, greater independence and less burden on the carer.

Arm weakness and impaired upper limb function in neurological conditions are not simply a problem of muscle strength. They are a complex disturbance of movement control, tone, sensation, coordination, pain, shoulder positioning, hand function and the use of the arm in everyday life.

This is why rehabilitation should be individual, safe and functional. It should address the trunk, scapula, shoulder, elbow, wrist, hand, fingers, sensation, muscle tone and the specific activities the patient needs.

For patients after a stroke, a brain injury, and those with MS, Parkinson's, cerebral palsy and other neurological conditions, the aim of therapy is not merely to perform a movement in the therapy room. The aim is for the arm to return, as far as possible, to the patient's life.