Kinesiotherapy: physiological foundations and principles. Effects of therapeutic exercise on major organ systems. Principles of exercise prescription and dosage

01Physiological foundations

Kinesiotherapy (kinesitherapy, from Greek kinesis, movement) is treatment and prevention by movement: exercise the patient does, and movement given to them. It aims to prevent decline, restore function after illness or injury, compensate for what cannot be restored, and keep the patient independent. The same movement can serve different aims depending on its starting position, range, resistance and repetitions.

The key idea is that the body is a builder that follows demand. Put a load on a tissue and it adapts to carry it more easily next time; take the load away and it removes what it no longer needs. Muscle, bone, tendon, heart and even brain circuits all follow this rule, which sport science calls SAID: specific adaptation to imposed demands.

The muscle as the engine

A skeletal muscle is made of two kinds of fibres. Extrafusal fibres make the force. Intrafusal fibres, inside the muscle spindle, sense length and its change and feed the reflexes and the sense of position (proprioception).

A nerve and the fibres it drives form a motor unit. For any task the small, slow units are recruited first and the large, fast ones only as force rises (the size principle). So light exercise trains mostly type I fibres; only heavy or fast efforts reach type II. This is why a strength programme needs real load.

Muscles also fall into two working groups, an idea the professor's school builds its programmes on. Postural (tonic) muscles (such as the upper trapezius, iliopsoas, hamstrings) tend to shorten and tighten under strain, so they are relaxed and stretched. Phasic (dynamic) muscles (such as the gluteal and abdominal muscles, the lower scapular fixators) tend to weaken and lengthen, so they are activated and strengthened. An imbalance between the two alters joint alignment and loads joints, ligaments and discs. This model, from Janda's work, simplifies. The groups are defined by how the muscles behave, not by fibre type (the hamstrings, a "tight" group, have many fast fibres), and the evidence for fixed "tight" and "weak" groups is limited, but it is a useful guide for planning.

Energy for movement

All three run at once; their shares shift with intensity. Endurance training enlarges the oxidative system; strength and sprint training the first two.

02Hypokinesia: what rest does

Hypokinesia means too little movement; its extreme is immobilisation, in bed or in a cast. Rest was once the treatment for most illnesses; now we know it is a cause of disease in itself, harming every system within days. The picture to keep: the body dismantles whatever it does not use.

Recovery takes far longer than the loss, especially in older people, who may never fully regain what a short stay in bed took. Hence the modern rule: as little bed rest as possible, and movement from the first day if the condition allows: sitting up, breathing exercises, ankle pumps, turning, standing.

03Effects of therapeutic exercise on the major organ systems

Muscle

• Strength. In the first 4 to 8 weeks, most of the gain is neural: more motor units are recruited, they fire faster and in better time, and opposing muscles get in the way less. After that the fibres themselves grow (hypertrophy), mainly type II fibres.
• Endurance. More mitochondria, capillaries, oxidative enzymes, myoglobin and glycogen stores; fibres shift from IIx toward IIa. The muscle extracts more oxygen and makes less lactate at the same work.
• Tendon and connective tissue become stiffer and stronger with progressive loading.

Heart and circulation

The heart is a muscle that adapts like any other. Endurance training enlarges the left ventricle and plasma volume, so each beat pumps more (stroke volume rises), and vagal tone rises, so the resting heart rate falls.

The lower heart rate and pressure at a given load explain why a patient with angina can walk further before pain: the heart's oxygen demand (roughly heart rate × systolic pressure) for the same walk is smaller. In heart disease, much of the benefit comes from the trained muscles and vessels rather than the heart itself.

Lungs

Here the honest message differs from the old one. In healthy people and in COPD, lung volumes and FEV1 hardly change with training. What changes is everything around the lungs: trained muscles produce less lactate and carbon dioxide, so less ventilation is needed for the same work; breathing becomes slower and deeper and so more efficient; the breathing muscles get stronger; and fear of breathlessness fades. The result is less breathlessness for the same task, the core of pulmonary rehabilitation. Movement and deep breathing also open collapsed lung bases and clear mucus, which is why bed-bound patients are sat up and made to breathe deeply.

Bone, joints and connective tissue

Bone remodels to the strains it meets (Wolff's law, the mechanostat). Impact and resistance loading slow bone loss and can increase density a little; balance training prevents the falls that break bones. Cartilage has no blood supply and is nourished by synovial fluid squeezed in and out by joint movement and loading, so motion feeds it and immobility starves it. Movement through the full range keeps capsules and ligaments supple and prevents contractures.

Metabolism

Contracting muscle takes up glucose without needing insulin, by moving GLUT4 transporters to its surface, and insulin sensitivity stays better for a day or two after each session. So exercise lowers blood glucose and HbA1c in diabetes, lowers triglycerides, slightly raises HDL cholesterol, and helps weight maintenance (for weight loss, diet matters more). It also lowers chronic low-grade inflammation.

Brain and mind

Exercise raises brain-derived neurotrophic factor (BDNF) and cerebral blood flow, supporting neuroplasticity: practised movements reshape the motor cortex, the basis of motor relearning after stroke. It improves mood (an effect on depression comparable to other first-line treatments in mild to moderate cases), anxiety, sleep and, in older people, cognition. A bout of exercise also raises the pain threshold (exercise-induced hypoalgesia) through endogenous opioids and descending inhibition, though this may be blunted in some chronic pain states, where exercise is started gently.

04Principles of kinesiotherapy

The professor's school builds a kinesiotherapy programme in four steps:

1. 1

   Kinesiological analysis

   Assess the body and its function: posture and movement (somatoscopy), measurements, manual muscle testing and goniometry, gait and daily activities.
2. 2

   Aims

   Set goals from the findings and the patient's rehabilitation potential: the patient is treated, not the diagnosis.
3. 3

   Forms and methods

   Choose the means: passive or active, analytic or general, in water or on land, with or without devices.
4. 4

   The exercise complex

   Write the actual session: exercises, order, starting positions, repetitions, rest, and how it will progress.

The training principles that run through every programme:

05Principles of exercise prescription

Exercise is prescribed like a drug: the right type, at the right dose, at the right interval, for the right length of time. The standard frame is FITT-VP.

Measuring intensity

The Karvonen formula turns heart rate reserve into a target: target = resting rate + chosen percentage × (maximal rate − resting rate). With a resting rate of 70, a maximum of 170 and 60 per cent: 70 + 0.6 × 100 = 130 beats per minute. A beta-blocker blunts the heart rate, so then perceived exertion or a heart rate range from an exercise test on the drug is used.

moderate activity for adults (or 75 to 150 vigorous)

150–300min a weekmoderate activity for adults (or 75 to 150 vigorous)

muscle strengthening of all major groups

2+days a weekmuscle strengthening of all major groups

balance and strength (multicomponent) for older adults

3+days a weekbalance and strength (multicomponent) for older adults

These WHO targets are for health. In rehabilitation the starting dose is set from the patient's assessment, often far lower, and raised toward them; some activity is better than none, and any amount of moving replaces harmful sitting.

Dosage in a session

A session has three parts, so that load rises and falls smoothly instead of all at once:

1. 1

   Warm-up, 5 to 10 minutes

   Light movement raises heart rate, muscle temperature and joint lubrication gradually.
2. 2

   Main part

   The exercises aimed at the goal, at the prescribed intensity.
3. 3

   Cool-down, 5 to 10 minutes

   Load falls gradually, so blood does not pool in the legs and the heart rate settles; then stretching.

Plotted against time, the pulse rises through the warm-up, peaks in the main part and falls in the cool-down: the old school's "physiological load curve", used to check that a session was neither too flat nor too steep.

Within a session, the load is changed by:

• the starting position (lying, sitting, standing: the higher the centre of gravity and the smaller the base, the harder);
• the range of movement and the length of the lever (a straight arm is heavier than a bent one);
• the number of repetitions and sets, and the tempo;
• the rest between exercises and the number of muscle groups at work;
• the complexity and coordination demanded;
• resistance and apparatus;
• the patient's mood and focus, which the old school counted too.

How to progress each kind of exercise, step by step, is set out in active and active-assisted kinesiotherapy. The general rule is to raise one variable at a time, by small steps (often no more than about 10 per cent a week in volume), and only when the current dose is done well without lasting pain or exhaustion.

06Safety: when not to exercise, and when to stop

Exercise has very few absolute contraindications; most are temporary states where the heart, lungs or a tissue cannot take extra load yet.

Stop at once for chest pain, faintness or dizziness, confusion, breathlessness out of proportion, pallor or cold sweat, a fall in blood pressure as effort rises, a new arrhythmia, or severe joint pain. Patients with heart disease are risk-stratified, and many tested, before training; see cardiopulmonary rehabilitation.