PTY3051 Week 0 – 2: Aquatic physiotherapy

How do different structures in the body differ in relative density?

High: bone & muscle (reduced with osteoporosis & muscle atrophy)

Low: air & fat (increases with inactivity)

Effect of hydrostatic pressure on body

- Increased proprioception at depth?

- Increased resistance to chest expansion making respiration difficult at depth

- Oedema shifts from interstitial region to blood plasma

Buoyancy and relative weightbearing at different depths

C7: 8% WB

Xiphisternum: 30% WB

ASIS: 50% WB

Note ↑ peak WB with impact activities

Respiratory effects of immersion

- Due to relative central hypervolemia & pressure on abdomen (and hence upward pressure on diaphragm)

- Reduces TLC, FRC and vital capacity

- Increases airway closure & resistance

Cardiovascular effects of immersion

- Shift of fluids from interstitial spaces to blood plasma, causing a reduction in swelling

- Increased fluid/blood return from distal limbs

- Leading to increased SV & hence CO due to increased central circulation

Renal effects of immersion

- Diuresis due to ↓ vasopressin, ADH, renal sympathetic nervous activity, & renin-angiotensin-aldosterone system activity

- Natriuresis & Kaliuresis

Effects of immersion in warm water on pain

- Large, myelinated fibres from thermal & mechanoreceptors close the gate to smaller nociceptive activity

- ↑ circulation

- ↑ collagen flexibility & extensibility

Effect of buoyancy on pain

- Reduces stress & compression & mechanical stress on tissues

- ↑ROM, causing more synovial fluid movement and improving nutrition

Effect of hydrostatic pressure on pain

- ↓ Oedema

- ↑ sense of well being

- ↓ sympathetic activity due to reflex ↓ HR

Effect of immersion on exercise

- Increased core temperature due to reduced heat dissipation in warm pools

- Increased RPE and reduced HR at submaximal VO2

How can buoyancy affect movements?

Buoyancy assisted: either grade 1 strength exercises or stretches (+/- floaties)

Across buoyancy: Grade 2 strength exercises

Buoyancy resisted: Grade 3 strength exercises

How would you change your centre of buoyancy, and why?

- Changing it by bringing a limb e.g. hand / arm out of the water while in box squat / supine

- Using it to challenge core stability

What influences drag?

- Created by pressure gradient behind moving objects in fluids

- With surface area and velocity of movements

Practical applications of drag

- To assist or resist movements

- Maintain posture against turbulence (isometric muscle activity & balance)

- Modifying surface area to increase drag

Differences between buoyancy and drag

Buoyancy:

- Upthrust force

- Dominant at lower speeds

Drag:

- In all directions

- Dominant at higher speeds

Screening for aquatic physio

- Cardiorespiratory conditions (no AMI within past 6/52)

Check with GP or respective specialist for stability of conditions:

- Respiratory

- Neurological

- Infections (no open wounds, gastroenteritis or faecal incontinence)

- Head sensitive conditions (MS & chronic fatigue)

- Diabetes

- Pregnancy

- Cancer / Immunocompromised

- Obesity (↑WOB from abdominal contents)

Examples of conditions referred to aquatic physiotherapy

- Musculoskeletal conditions e.g. hip/knee OA, LBP / postoperatively (orthopaedic surgery)

- Neurological conditions e.g. MS, PD, strokes, SCI, adult CP, GBS, post-polio syndrome

- Cardiorespiratory conditions e.g. COPD / heart failure

- Mental health e.g. depression & dementia

- Autism, breast cancer, muscular dystrophy or CRPS

- Labour related pain / obesity / post menopause

Halliwick style aquatic physiotherapy

- Initially, retraining breath holding underwater (may be lost in e.g. strokes)

- Progress to moving in single planes (e.g. weight shifts in box squat position)

- Progress to gliding in water (prone, supine or side-lying) to and from box squats

- Progress to gliding in multiple planes (note side-lying not terminal due to instability)