Kennedy’s disease is a rare inherited condition that affects the nerves responsible for controlling muscle movement. Although it develops gradually, it can cause changes in strength, walking, balance and everyday activities. Understanding the condition and how physiotherapy can help is an important part of managing its effects.
What is Kennedy’s disease?
Kennedy’s disease, also known as spinal and bulbar muscular atrophy (SBMA), is a genetic form of Motor Neurone Disease (MND) that affects specialist nerve cells called motor neurons. These cells carry messages from the brain and spinal cord to the muscles, telling them when to contract.
In Kennedy’s disease, these nerve cells gradually become damaged. As a result, muscles receive fewer effective signals, leading to weakness and a reduction in muscle size, known as muscle wasting or atrophy.
The condition is caused by a change in a gene on the X chromosome. It mainly affects men, and symptoms most commonly begin between the ages of 30 and 50. The condition is rare, with one estimate suggesting it affects around one in 300,000 males, although it may be under diagnosed.
What are the symptoms?
Symptoms usually develop slowly and can vary considerably between individuals. Common symptoms include:
- Muscle weakness: Often affecting the hips, thighs, shoulders and arms, making activities such as climbing stairs or getting up from a chair more difficult.
- Muscle cramps and twitching: Some people experience painful cramps or small, involuntary muscle movements.
- Changes in walking and balance: Weakness can make walking more difficult and increase the risk of trips and falls.
- Speech and swallowing difficulties: As the condition progresses, the muscles involved in speaking and swallowing may become affected.
- Other physical changes: Some men experience breast tissue enlargement or reduced fertility due to changes in how the body responds to male hormones. Not everyone experiences all these symptoms, and the rate of progression differs from person to person.
Can physiotherapy help?
There is currently no established cure for Kennedy’s disease, but physiotherapy can help people maintain their mobility, independence and quality of life for as long as possible.
Treatment is tailored to each individual and may include:
Strength and exercise: Carefully selected exercises can help maintain muscle function and general fitness. Exercise should be adapted to current abilities, with attention to fatigue and avoiding excessive muscle strain.
Balance and walking practice: Exercises can help improve movement control and confidence. A physiotherapist may also recommend walking aids or ankle-foot braces to improve safety and reduce the risk of falls.
Stretching and movement: Gentle mobility exercises can help maintain joint movement and address tightness that may develop alongside muscle weakness.
Managing everyday activities: Physiotherapy can help people find safer and more energy-efficient ways to complete daily tasks, while occupational therapists can recommend equipment or adaptations at home.
Kennedy’s disease is best managed by a team of healthcare professionals. Speech and language therapists can help with speech or swallowing difficulties, while medical specialists monitor other aspects of health.
The key message
A diagnosis of Kennedy’s disease can bring uncertainty, but support is available. Although the condition gradually progresses, physiotherapy can help people remain active, manage changes in mobility and maintain independence.
The aim is not simply to exercise more, but to find the right balance between activity, recovery and safety, while helping each person continue doing the things that matter most to them.
