Hydrotherapy

Buoyancy removes most joint load, so movement that is impossible or too painful on land becomes achievable. Water resistance strengthens in every direction without equipment. Hydrostatic pressure reduces swelling. Warm water lowers muscle tone and pain.

Together these mean a patient can often start meaningful exercise in water weeks before land-based exercise is tolerable, which prevents the deconditioning that would otherwise occur while waiting.

Early rehabilitation after joint replacement and lower limb surgery, osteoarthritis where land exercise is too painful to begin, rheumatological conditions, neurological rehabilitation where balance is impaired, chronic pain and fibromyalgia, and obesity rehabilitation where joint load is the barrier.

In fibromyalgia particularly, warm water exercise is one of the better-supported starting points, because it lowers the initial pain barrier that stops most programmes before they begin.

Bone and muscle adapt to load, and water removes load. That is precisely why it helps at the start and precisely why staying in the water stops producing gains.

We move work onto land as soon as it is tolerated. A patient who has exercised only in water will have improved cardiovascularly but may still not be ready to walk further on land.

Open wounds, active infection, uncontrolled epilepsy, severe cardiac impairment, unmanaged incontinence, and significant swallowing impairment where water inhalation is a risk.

If you cannot manage steps or use a wheelchair, ask for pool access at your centre to be confirmed in your plan. Access is often the real barrier for the people who would benefit most.

Walking and gait work, range of movement, strengthening against water resistance, and balance work made safe by the water. Session length is shorter early on because warm water is more fatiguing than people expect.

Temperature is higher than a swimming pool, which reduces tone and pain and is itself a consideration in some cardiac and respiratory conditions.

The aim from the first session is the land. Water removes load, and load is what daily life requires — so the programme progressively shifts to land-based work as capacity allows.

A programme that stays in the pool because the pool is comfortable is not progressing.

For knee and hip osteoarthritis, a Cochrane review of 13 trials with 1,190 participants found moderate-quality evidence that aquatic exercise gives small, short-term improvements in pain and disability, about five points on a 100-point scale, compared with control groups 1. No serious adverse events linked to aquatic exercise were reported in those trials 1.

In fibromyalgia, a Cochrane review of 16 trials found low- to moderate-quality evidence that aquatic training improves wellness, symptoms and fitness compared with control groups 2. When aquatic and land-based exercise were compared directly, results were similar except for muscle strength, where very low-quality evidence favoured land 2.