13.3 Therapeutic Exercise: ROM, Flexibility & Strength

Quick Answer: Prescribe PROM → AAROM → AROM, then stretching matched to end-feel and healing stage. Strength progresses isometric → isotonic (concentric/eccentric) → isokinetic and from simple to SAID-specific work, with progressive overload. MMT 5/5 is not a 1RM and is not sport clearance. Do not load an unstable fracture, blast through acute inflammation, or ignore post-op ROM limits. Traps: heavy open-chain terminal knee extension on an early ACL graft, and ballistic stretching in acute inflammation.

PA8 Domain IV, task 0403, asks the AT to prescribe therapeutic exercises following evidence-based practice to address impairments and enhance activity and participation. This section is the ROM, flexibility, and strength slice (neuromuscular control, aerobic work, and agility continue later). Kisner, Colby, and Borstad remain the technique backbone; Knight and Prentice supply the AT loading logic: specificity, overload, and respect for healing.

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ROM: PROM, AAROM, AROM

Passive ROM (PROM) is motion produced by an external force (clinician, contralateral limb, CPM or pulley, gravity) with little or no voluntary contraction of the prime movers. Use it to maintain joint and connective-tissue mobility, synovial nutrition, and a map of available range when active contraction is contraindicated or too weak. PROM is not stretching—stretching takes tissue beyond currently available ROM—and PROM does not prevent atrophy or build strength.

Active-assistive ROM (AAROM) is active effort plus help (pulleys, a wand, a slide board, your hands) when the prime mover cannot complete the range without substitution.

Active ROM (AROM) is unassisted motion from the muscles crossing that joint. It adds a muscle pump, proprioception, and a trace of strength. For an already strong muscle, AROM will not hypertrophy it. That is why a full AROM session is not a strength program.

Indications by stage: acute protected PROM or AAROM in a pain-free range; AROM as soon as the patient can control the segment without substituting or flaring inflammation. Kisner/Colby precautions: do not force motion that disrupts healing; unstable fracture; uncontrolled acute inflammation (gentle, limited, pain-free motion is often still useful—complete immobility has its own morbidity); and any situation in which movement is life-threatening. Too much ROM announces itself as increased pain and inflammation after the session. Post-op ROM limits (brace locks, no active flexion against gravity, no external rotation past a surgeon’s number) are POC law until the physician changes them (Standard 1).

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Stretching and End-Feel

Match the stretch to tissue and irritability.

• Static stretching: a low-load hold (commonly on the order of 15–60 seconds, repeated) once tissue can tolerate end-range. Long-duration, low-load holds are the usual choice for contracture.
• Dynamic stretching: controlled movement through range; useful as a warm-up when tissue is quiet.
• Ballistic stretching: bouncing into end-range. Not for acute inflammation, untrained tissue, or post-op restrictions—it is poorly controlled and easy to overshoot a weak repair.
• PNF: hold-relax (isometric contraction of the tight muscle, then a further stretch) and contract-relax (isotonic/concentric contraction, often with rotation in PNF patterns, then stretch). Use when the patient can produce a controlled contraction without flaring the repair.

End-feel (Cyriax / Kaltenborn teaching used throughout AT education) is the quality of resistance at the end of passive range. You cannot prescribe stretch intelligently without it.

A firm capsular end-feel in remodeling is a stretching candidate. An empty end-feel in acute inflammation is a stop. Forcing empty or spasm end-feel is how you restart the inflammatory clock. A springy block is a mechanical problem, not a flexibility problem—do not bounce it away.

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Strength: Mode, Chain, SAID, Overload

Isometric: joint angle held, no appreciable motion. Early when motion is limited or painful through range; use multiple angles because isometric strength is angle-specific. Cue breathing; Valsalva spikes blood pressure and is a precaution in hypertensive or post-surgical patients.

Isotonic: visible motion against resistance.

• Concentric (CON): muscle shortens under load.
• Eccentric (ECC): muscle lengthens under load; can produce higher force and more delayed-onset muscle soreness; useful later for tendons when criteria allow.

Isokinetic: constant velocity, accommodating resistance (dynamometer). Useful for quantified testing and later-stage loading when available—not a week-1 requirement in a high-school ATR.

A common AT progression is isometric → isotonic (CON/ECC) → isokinetic and functional/power. That is a scaffold, not a religion: a quiet isometric at 30° and a light closed-chain squat can coexist on the same day if both are indicated.

Open kinetic chain (OKC): distal segment free (seated knee extension, straight-leg raise). Useful for isolated strength; can increase tibiofemoral shear in some ranges.

Closed kinetic chain (CKC): distal segment fixed (squat, step-up, push-up). More co-contraction and joint compression; often better tolerated early at the knee when form is clean and the knee does not travel excessively past the toes under load.

SAID (specific adaptation to imposed demands): tissues adapt to the specific demand you impose—velocity, joint angle, muscle action (CON vs ECC), energy system, and skill. Quad sets do not prepare a cutting athlete. Knight’s therapeutic-exercise teaching and Kisner/Colby both treat specificity as non-negotiable. Progressive overload raises stress (load, range, speed, volume, instability) as the tissue and motor system adapt. The +2 rule used in many clinics (when two extra clean reps appear, raise load next session) is one practical overload heuristic—not a BOC-mandated formula. Reversibility: unused capacity fades; a week of exams without a HEP is a regression risk.

Training goals differ:

• Muscle endurance: lower load, higher repetitions, shorter rest
• Hypertrophy: moderate-to-high load, moderate reps, enough weekly volume
• Power: force × velocity—once a strength base exists (later remodeling, criteria-based); do not prescribe box-cut bounding in the inflammatory phase

MMT versus 1RM. Manual muscle testing (MMT, 0–5) is an ordinal, gravity-referenced break test. 5/5 means the muscle held against strong manual resistance in that position—it is not a one-repetition maximum (1RM), not a hop-test limb-symmetry index, and not return-to-play. Many post-op patients score 4+ or 5 and still fail a single-leg squat. Use MMT to screen; use measurable load, repetition-maximum estimates, handheld dynamometry, and functional tests to progress. Do not max-test a 1RM through an unstable fracture, a hot joint, or a surgeon’s ROM lock.

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Precautions and Classic Traps

Do not apply heavy resistance through an unstable fracture, through acute inflammation that is still hot and empty, or past a surgeon’s ROM stop. Watch substitution (hip hike, trunk lean, contralateral push-off), effusion the next morning, and quality of end-feel. If yesterday’s load produced a 2+ effusion, that was not SAID—it was too much.

Trap 1: heavy open-chain terminal knee extension (TKE) on an early ACL graft. Quadriceps contraction toward full extension (often taught as caution in the last ~30–45°) increases anterior tibial translation and graft strain. Kisner/Colby precautions include avoiding resisted OKC knee extension in that window for weeks (commonly cited as at least 6 and as long as about 12—follow the surgeon and graft type) and avoiding distal-tibia resistance until control is established. Early quad work uses isometrics in a safe angle, a straight-leg raise only if there is no lag, and controlled closed-chain in ranges that do not dump the knee forward. This is not never open-chain forever; isolated OKC later is useful when criteria and the physician allow. Hamstring grafts also need cautious flexor loading because of harvest morbidity.

Trap 2: ballistic stretching in acute inflammation. Bouncing on a 48-hour hamstring strain asks a weak clot and irritable muscle to behave like a warm, remodeling tendon. Use protected PROM, then static or PNF when the end-feel is no longer empty.

Prescribe like task 0403: name the impairment, pick the mode, dose it, teach it (0402), and advance only when 0401 criteria say the tissue can take the next SAID demand.