Functional movement & weakness

• A heavy feeling down one side of the body
• A limb that doesn’t feel like part of you
• Dropping things
• Trouble walking

Weakness often changes with tiredness, pain and how much attention you pay to moving.

• A functional seizure, panic attack or dissociative episode
• A migraine with aura
• A physical injury or a lot of pain
• Long spells of tiredness or bed rest
• No obvious trigger at all
• Waking up from sleep or an anaesthetic

Many people have no clear trigger. That doesn’t make the weakness any less real.

Doctors look for “positive signs”. In Hoover’s sign, a weak leg pushes down poorly when you try, but its strength comes back when you lift the other leg, because then the movement is automatic.

No one sign is perfect, so doctors look at several signs together.

Functional tremor is rhythmic shaking, usually of an arm or leg. It can come and go during the day, change speed, and sometimes be violent. It often starts suddenly.

It is often most noticeable when the person is relaxed. Stress doesn’t have to be part of it.

Many people with functional tremor also feel an “internal tremor” that no one else can see. Everyone has a very slight normal tremor, and FND can make it feel much bigger.

Functional dystonia is a muscle tightness that changes posture, such as a clenched hand, curled fingers, or an ankle that turns in and points down. It can be brief spasms or last a long time.

It can start after an injury, limb pain or a long time keeping a limb still. Experts think the brain’s “map” of the limb gets mixed up, so the odd position starts to feel normal.

Pain is common but not always present.

Some people have sudden jerks or twitches (doctors call these myoclonus). Like other functional movements, they are involuntary.

One leg may feel weak and drag, often with the ankle turned in or out. Some people say their foot feels stuck to the ground.

The knee may suddenly buckle, usually along with leg weakness. If both knees buckle at once, a person may drop to the ground. Other causes, like knee problems, should be checked too.

Some people walk with stiff legs, feet wide apart and small steps, as if walking on ice. This often starts after a fall, when fear of falling again takes hold.

Fear of falling is understandable. Rebuilding confidence, step by step, is part of rehab.

Some people sway a lot, or find it hard to stand still even though walking is fine. This can improve when they are distracted.

Instead of straining to move a weak leg, a physio might ask you to kick a ball, or look at a spot ahead while you walk.

Distraction helps “open the door” to more natural movement. It isn’t meant to be used all the time, just as a way in.

Automatic movements using both legs or both arms together are usually more helpful than exercises that focus only on the weak limb.

Because deliberate effort can make functional movement worse, being told to “just try harder” doesn’t help. Paying close attention to the symptom is one of the things rehab works to change.

Expert physiotherapists agree that treatment should start with education: what FND is, and why the body is behaving this way.

Feeling confident in the diagnosis makes people more willing to try new approaches.

Physio works on movement habits that have become stuck, and on the attention people pay to their symptoms. It uses automatic and well-practised movements to bring normal movement back.

Physios often encourage putting weight through the legs early, and keep hands-on support to a minimum.

A key goal is giving you strategies to manage on your own after therapy ends. Treatment should feel positive and free of judgement.

Some people need to steady their activity levels with pacing before they are ready to build up. No one should feel forced.

Progress is usually slow and uneven, with some “back to square one” days. What matters is the overall direction over weeks and months.

Activity may make symptoms worse for a while, but building up slowly doesn’t cause damage.

Make a sweeping movement with the shaking arm, like an orchestra conductor, on top of the tremor. Then gradually make it wider and slower until it stops.

Another idea: a friend taps a steady beat that you copy with your good hand. Then they slow it down, and you see whether the tremor follows.

• Change how you sit, or where you put your weight
• Keep the foot flat on the floor for as long as you can
• Tap your other foot while copying someone else’s changing movements

Tremor often involves tensing all the muscles in a limb at once, so muscle relaxation practice can help too.

• Hum or sing while you walk
• Jog lightly, if you are able
• Listen to music
• Shift your weight side to side before you start
• Slide your feet as if ice-skating
• Try moves from things you used to love, like dancing or sport
• Walk backwards

• Change your sitting and standing positions
• Move the affected part whenever you can
• Picture the limb in a normal position in your mind
• Use a mirror to give your brain feedback

Experts are still learning which techniques help most for dystonia, so work with your therapist on what suits you.

FND therapists usually avoid unnecessary equipment, because it can change how you move and lead to joint pain and weaker muscles.

Equipment can be the right choice if you would be at risk of harm without it, or if disabling symptoms continue after treatment. A therapist who understands FND can help you decide.

Limbs can end up held in unhelpful positions, like an arm cradled on the lap or an ankle turned in. These can feel natural, but may reinforce the problem. Rehab aims to relearn normal movement.

Occupational therapists help you get back to everyday tasks, like self-care, cooking, work or study. They use education, practice within real activities, and self-management skills.

Speech and language therapists help with functional voice, speech and swallowing symptoms.

If worry or anxiety is part of the picture, a psychological therapy aimed at it can help with tremor and other symptoms.

Some people find that hypnosis helps, and a few learn self-hypnosis to practise at home.

• Ask about their therapy goals, so you can cheer them on
• Believe them, even if scans are normal
• Join in with rhythm or music exercises, if they want
• Let them do as much as they can for themselves
• Notice and celebrate small steps

• “But you walked fine yesterday”
• “It’s all in your head”
• “Just try harder”

Symptoms that change from day to day, or with distraction, are part of FND. Trying harder can make functional movement worse.

Relying on carers for a long time can reduce confidence, fitness and independence, and can strain relationships. That’s why therapists encourage people to do what they can themselves.