Weakness and Stiffness on One Side After a Stroke: What Physiotherapy Targets

Reviewed by Dr. Anuradha Tyagi — Senior Neuro Rehabilitation Specialist, BPT, MPT · Meet the team

Two words often arrive together on a discharge summary after a stroke: hemiparesis and spasticity — or, plainly, “weakness on the left side” and “increased tone in the right arm”. Families are handed them at a busy moment and left to interpret them online. Here is what each means, and what physiotherapy works on.

World Physiotherapy Day falls on Tuesday, 8 September 2026, with the theme “The role of physiotherapy and physical activity in the prevention, management, and rehabilitation of cardiovascular disease and stroke” (#WorldPTDay). Prevention takes most of the attention on the day; this is the other half.

What weakness on one side actually means

Movement instructions cross sides on the way down from the brain, so damage on one side shows up as weakness on the opposite side of the body. Hemiparesis means that side is weak; hemiplegia means there is little or no voluntary movement in it — degrees of the same problem.

The muscles themselves are usually healthy; the problem is upstream, in an instruction not reaching them cleanly. That is why the limb feels heavy rather than tired, why trying harder does not solve it, and why practice matters: the nervous system reorganises around damage when it is used.

Day to day: a hand that will not open to take a cup, an arm that catches in sleeves, a leg that drags its toes, tiredness out of proportion to the distance walked, dulled sensation on that side.

Why the arm is so often worse than the leg

The leg comes back and the arm does not. Three things drive this.

Anatomy. The commonest strokes affect a vessel supplying a large area of brain given over to the face, arm and hand. The region controlling the leg sits higher and further in, fed by a different vessel, and is more often partly spared.

The job. A leg takes weight and steps, which a coarse whole-limb pattern manages usefully. A hand needs fingers moving independently, which depends on the most direct pathways — the ones most easily lost.

Use. Once someone stands, the leg is practised hundreds of times a day whether anyone plans it or not. The arm is not: a whole day can pass using only the strong hand. This is the reason therapy can do most about.

What stiffness — spasticity — actually is

The affected side is often floppy at first. Over the following weeks that changes, and the limb starts to resist being moved. That resistance is spasticity: muscles that should be resting are held partly switched on and object to being stretched, especially when moved quickly. The brain normally sends steadying signals down the spinal cord that keep reflexes in check; when those pathways are damaged, the reflexes become overactive.

It follows a pattern: in the arm the shoulder draws in, the elbow bends and the fingers curl towards the palm; in the leg the limb straightens and the ankle points down and inwards, so the toes catch. It is not universal, and not automatically bad: some tone in the leg helps a person stand. What matters is whether it gets in the way.

Why stiffness is worth taking seriously

A joint held in one position and not taken through its range will shorten. Tissue adapts to the length it is kept at, and after some months the restriction is no longer about tone — the joint will not go there. That is contracture, harder to undo than to prevent. Nearer-term costs matter too:

• Pain — a weak shoulder sits poorly in its socket and is easily hurt by being pulled during transfers.
• Hygiene — a closed fist or an armpit that will not open is hard to wash and dry; damp skin breaks down.
• Dressing and handling — sleeves, nail-cutting and bed-to-chair transfers become harder and less safe.
• Walking — an ankle that points downwards turns every step into a trip hazard.

Stiffness that suddenly worsens is usually a message: pain anywhere pushes tone up — a urinary infection, constipation, a pressure sore, a full bladder. If tone changes abruptly, look for a cause and get it checked.

What physiotherapy actually targets

There is no single treatment for either problem. Assessment comes first, and the plan is built around the individual — what they could do before, what they can do now, what is realistic. Broadly, neuro physiotherapy after a stroke works on:

• Positioning and handling — how someone lies, sits, is moved, and how the weak arm is supported. Hours in a poor position undo a great deal.
• Range and stretch — taking joints slowly through the movement available so tissue does not shorten. Never forced, always taught hands-on: a stroke-affected shoulder is easily injured.
• Strengthening what is working, including the trunk and stronger side. The old belief that strengthening worsens stiffness has not held up; weakness is the bigger obstacle.
• Task practice — repetition of real actions such as reaching for a glass or standing from a chair, hard but achievable. Most change is made here.
• Balance and walking — sitting balance, then standing, then weight onto the affected leg, then stepping. Gait training is structured work, not just walking further each day.
• Hand and daily-living goals — dressing, feeding, grooming and hand use are worked on by the physiotherapy team here, within the same plan.
• Equipment and orthoses — an ankle-foot orthosis, a resting splint, the right walking aid or seating, fitted and reviewed. The wrong aid bought online can entrench a pattern.

Where stiffness is severe and confined to particular muscles, medical options exist — oral medicines, botulinum toxin injections, occasionally surgery. Whether any is appropriate is a decision for the treating doctor and neurologist. None replaces the therapy work.

What the family does between sessions

Six one-hour sessions a week is six hours out of more than a hundred waking ones. The rest belongs to the family, and much of the change is produced there.

• Position the person through the day and at night as your therapist has set out, including how the weak arm is supported when sitting.
• Approach from the affected side and put things there, so it stays in the person’s world.
• Follow the home programme as given — the same exercises, the stated number, at the stated times.
• Build the weak arm into ordinary tasks where it is safe to, such as steadying a plate.
• Allow rest. Fatigue after a stroke is real; more is not automatically better.

One qualifier above the rest: never attempt handling, stretching or transfers you have not been shown and watched doing. Formal caregiver education and training exists for this, with a therapist observing you until it is safe. For the wider timeline, see our guide to the first 90 days after a stroke.

When to call a doctor rather than book more therapy

Some things are not therapy problems. Contact the treating doctor, or emergency services, rather than the clinic if you see:

• Sudden new weakness, facial droop, slurred speech or loss of vision — an emergency; get to a hospital immediately.
• A limb that becomes swollen, warm, discoloured or newly painful, particularly a calf — same-day medical assessment.
• New, severe or rapidly increasing pain, especially at the shoulder.
• Broken skin, or redness over a bony point that does not fade once pressure is off.
• A sudden unexplained increase in stiffness, or fever, drowsiness, confusion, or choking on food or drink.
• Any fall with a knock to the head — urgently, if the person takes blood-thinning medication.

What physiotherapy does not do

Physiotherapy does not repair the brain tissue the stroke damaged and cannot reverse the event. No responsible therapist can promise that a particular arm will become usable, that someone will walk unaided, or put a number on the odds. Recovery varies enormously: it depends on how much of the brain was affected and where, on age and other conditions, on how early and how consistently the work is done, and on much nobody can measure in advance.

Nor does therapy substitute for medical management: blood pressure, diabetes, cholesterol, heart rhythm and the medicines that lower the risk of a second stroke are the doctor’s. Spasticity, too, is managed rather than removed. Weakness and stiffness respond to structured, repeated, well-directed work far better than to waiting.

Seeing someone at Neuranta

Neuranta is an independent neuro and pediatric rehabilitation centre at Plot No. 440, Sector 39, Gurugram, Haryana 122003, seeing people after a stroke on an inpatient, day-care and outpatient basis. Every programme begins with an individual assessment; the plan, its intensity and its length follow from that, and differ from person to person.

If you are unsure what the weakness or the stiffness needs, call or WhatsApp +91 70786 42986, Monday to Saturday, 8:00 AM to 7:00 PM (closed Sunday), or request an assessment. Our stroke rehabilitation page sets out what a programme involves.

This is general information, not personalised medical advice; discuss anything specific with the treating doctor and therapy team.