Hydrotherapy
Hydrotherapy in the strictest sense refers to the therapeutic use of water. Pool therapy should be considered for patients with problems arising from muscle weakness, loss of joint mobility, poor coordination or balance, pain or lack of confidence. The particular value of pool therapy over dry–land treatment is derived from buoyancy, which counteracts gravity, provides support and relieves weight–bearing pressure on joints, for example in degenerative conditions. The warmth of the water reduces pain and can relax muscle spasm. The medium enables mobility for patients who may be wheelchair–bound or recovering from prolonged immobilization. Importantly, it also provides for enjoyment, recreation and laughter which are vital aspects or rehabilitation. Physiotherapists should consider pool therapy when treating patients with:

Indications

1. Ankylosing spondylitis.
2. Osteoarthritis
3. Rheumatoid arthritis.
4. Juvenile chronic polyarthritis.
5. Spondylosis.
6. Capsulitis.
7. Mechanical spinal disorders.
8. Polymyalgia rheumatica.
9. Major fractures especially of the lower limbs or spine.
10. Orthopedic surgery.
11. Neurological disorders such as hemiplegia, paraplegia, tetraplegia, polyneuropathy.
12. Children derive particular benefit from the freedom of movement afforded by the water.
13. Pool therapy is also of value for maintaining fitness and relieving backache during pregnancy and after childbirth.

Principles of Hydrotherapy Treatment
Strengthening muscles
Muscles are strengthened by being worked progressively against graded resistance. In the pool, resistance may be from buoyancy, turbulence.

Buoyancy
Movement downwards in the pool are resisted by buoyancy. Floats which may be of different densities may be used to increase the effect of buoyancy.

Turbulence
This is created by movement through water and is increased if the rate of movement is increased. The patient may move as a whole through the water–this is the principle underlying muscle strengthening using Bad Ragaz techniques. Alternatively, the patient may be fixed and move one limb at a time. Walking fast through water is useful for strengthening muscles and for improving cardiovascular fitness.

Joint mobility
Relief of pain and muscle spasm by the warmth of the water and by support from buoyancy can restore free movement of joints. Exercises for gaining mobility are generally slow, taken to the point of limitation, held, carried a bit further and then relaxed. Full–range sweeping movements also gain range (the speed is kept to a minimum so that the muscles are not working against turbulence). Hold–relax and repeated contractions may be used to gain joint movement–generally with the patient in lying (buoyancy supporting) or positioned so that buoyancy may assist in gaining the movement.

Mobilizations–Oscillatory passive movements can be applied to joints to gain range. Fixation is a problem and it may require two physiotherapists, one fixing and one producing the movement, to localize the effect to the joint being treated. Patients report considerable relief from pain following mobilization in the pool.

Coordination and balance
Patients can practice activities in standing, for example stride standing or walk standing , transference of weight, or arm movements. The buoyancy of the water relieves weight, for example 90% relief is obtained if the water is over the shoulders, therefore weight–bearing activities such as walking, stepping up and down, standing up and down can be practiced in the pool before the patient attempts these activities on land. Components of swimming can be practiced, for example the leg patterns of different swimming strokes may be performed while the patient holds the pool rail. Swimming and ball games, Bad Ragaz techniques and the Halliwick principles all help patients to regain coordination. The special value of the Halliwick approach is to teach the patient breathing control and balance in the water, thereby enabling him to the water–confident.

Pain relief
The general freedom of movement in a pool enables tissue fluid to flow through tissue planes, removing metabolites and improving nutrition. These effects, together with a feeling of well–being after physical activity, help to gain permanent reduction of pain. In some pools there is a facility for applying a high–pressure jet of water to a painful area. The patient is standing, sitting or lying and the physiotherapist directs the jet at the area to be treated and moves if either in circles or to and fro for 5–10 minutes. Patients report relief of the aching which is often associated with muscle spasm or tightness in degenerative conditions or chronic injury.

Cooling of the tissues–ice therapy
Ice therapy is the local or general application of cold for therapeutic and preventative uses. When ice is applied to the skin it melts and removes heat from the tissues–the energy required to change its state (the latent heat of fusion). The rate at which cooling occurs depends on the duration of the application, type of tissue (e.g. the thermal conductivity of muscle is greater than that of fat) and the patency of the blood vessels.

Therapeutically, ice can be used to relieve pain and muscle spasm, reduce swelling, reduce spasticity, facilitate muscle contraction, increase muscle endurance, reduce Haematoma formation, prevent pressure sores and promote healing of wounds.

Ice can be applied in towels, as a pack or by immersion in a bath. Damp towels dipped in an ice–and–water mixture, or containing crushed or flaked ice, can be wrapped round painful and swollen joints. Towels are applied longitudinally along muscles to reduce spasm. The towels are changed every few minutes. Ice baths containing 50–60% ice to water are used for painful swollen hands or feet. Spasticity can also be reduced by immersion in a bath.

In ice massage, an ice cube or ice lolly is wrapped a towel at one end and the free end is massaged over the skin. This can act as a counter–irritant if applied for 5–7 minutes to relieve pain and muscle spasm and as a preventative measure to avoid pressure–sore breakdown. This method may be used to facilitate the following:

1. Muscle contraction, by application over the appropriate dermatome for 3–5s.
2. Swallowing, by application over the skin just above the suprasternal notch or sipping iced water.
3. Speech, by application to the lips, tongue and inside of the cheek.