Foundation Sciences and Clinical Reasoning in Geriatric Physical Therapy
What the candidate must understand
Aging physiology is not disease, but the two interact. Know the normative changes: reduced maximal heart rate and VO2max, arterial stiffening with rising systolic pressure, decreased glomerular filtration, loss of type II muscle fiber area and motor units (sarcopenia), reduced nerve conduction velocity and proprioceptive acuity, decreased vestibular hair cells, lens yellowing and contrast sensitivity loss, reduced thirst and total body water, and declines in hepatic first-pass metabolism. Know how polypharmacy amplifies these: anticoagulants plus fall risk, antihypertensives plus orthostatic hypotension, sedative-hypnotics plus delirium, anticholinergics plus cognitive and bladder effects.
Clinical reasoning in geriatrics is hypothesis-driven and multifactorial. Use the disablement framework (impairment to activity limitation to participation restriction) and the International Classification of Functioning lens. Expect atypical presentations: infection without fever, myocardial infarction without chest pain, depression presenting as somatic complaint.
Traps
- Assuming a finding is "just aging" and stopping the workup (ageism trap).
- Assuming an abnormal value in an older adult is automatically pathologic when age-adjusted norms apply (e.g., D-dimer).
- Confusing sarcopenia (muscle mass/strength loss) with cachexia (disease-driven catabolism) or frailty.
- Ignoring the iatrogenic cause: new symptom after new drug.
Rule of thumb
For any new geriatric complaint, run the "geriatric giants" screen: falls, incontinence, delirium, depression, polypharmacy, sensory loss, malnutrition, and elder mistreatment. If a single mechanism does not explain the presentation, assume at least two contributors and treat the modifiable one first.