# Strengthening Techniques > Strengthening techniques in Physiotherapy: isometric, isotonic and isokinetic contractions, DeLorme and Oxford programmes, rep ranges for strength versus endurance, DOMS. - Canonical URL: https://prepelephant.com/topics/allied/physiotherapy/strengthening-techniques - Exam / course: Allied Health · Subject: Physiotherapy - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Strengthening Techniques", PrepElephant, https://prepelephant.com/topics/allied/physiotherapy/strengthening-techniques ## Direct answer A 25-year-old six weeks after femoral nailing needs her quadriceps back, and the choice among isometric, isotonic and isokinetic work decides how fast that happens. Isometric contractions build tension without joint movement and suit the earliest healing phases; isotonic contractions — concentric and eccentric — move a load through range and form the backbone of progressive resisted exercise; isokinetic contractions hold velocity constant on computerised machines, loading the muscle maximally at every angle. All strengthening obeys the overload principle, and dosage is anchored to the one repetition maximum (1RM) or its practical cousin, the ten repetition maximum (10RM). ## What you must remember - Contraction types: isometric (no length change — quad sets after surgery), concentric (shortening under load), eccentric (lengthening under load — the strongest and the chief trigger of delayed onset muscle soreness), isokinetic (constant angular velocity, e.g. Cybex and Biodex devices). - DeLorme progressive resisted exercise (1945): determine 10RM, then three sets of ten at 50, 75 and 100 per cent of it; the Oxford technique reverses the order — 100, 75, 50 — exhausting the muscle early when it is freshest. - Dosage by goal: strength 8–12 repetitions at roughly 60–70 per cent 1RM for novices, 2–4 sets; endurance 15–25 repetitions at low load; rest intervals 2–3 minutes between strength sets. - Fibre physiology: type I slow oxidative fibres serve posture and endurance, type II fast glycolytic fibres serve power; heavy loading recruits type II units in order of size (Henneman's size principle). - Delayed onset muscle soreness peaks 24–72 hours after unaccustomed eccentric work; lactate is not the cause — the old explanation is examined specifically to be rejected. - Isometrics raise blood pressure through combined pressor responses, so patients with hypertension or cardiac disease must avoid breath-holding and sustained maximal holds. - The same muscle needs 48 hours between heavy sessions; daily training alternates muscle groups or trains different qualities. ## Rebuilding quadriceps after immobilisation Week one: the knee is stiff, swollen and inhibited. Isometric quad sets — five-second holds, ten repetitions, hourly while awake — plus straight leg raises in a brace re-engage the muscle without stressing the healing femur. Add neuromuscular electrical stimulation if the quadriceps will not switch on, because arthrogenic inhibition after injury and surgery is neural, not mechanical. Weeks two to four: establish the 10RM for knee extension with light loads and begin open-chain concentric and eccentric work, emphasising the lowering phase. Introduce closed-chain mini-squats from 0 to 45 degrees and sit-to-stands, which load the quadriceps functionally with patellofemoral protection. Weeks four to eight: retest the 10RM, not reuse the old figure — progression means the load rises as capacity rises, ideally every one to two weeks. Move to step-ups, leg press and single-leg work; add balance components on a wobble board so strength arrives with control. Watch the knee: if effusion or night pain rises after a session, the dose overshot — drop ten per cent and rebuild. By week eight the patient should notice stairs, not the physiotherapist's chart, as the measure of success. ## Where students slip The DeLorme versus Oxford order is the single most-confused fact in this topic — remember DeLorme climbs the ladder, Oxford descends it. Students also swap 1RM and 10RM definitions, forget that eccentric contractions produce the highest force and the worst soreness, and prescribe breath-holding isometrics to cardiac patients. The exam catch on delayed onset muscle soreness is deliberate: "lactic acid accumulation" is the wrong option even though popular culture repeats it. ## Frequently asked questions ### In what order are loads lifted in the DeLorme and Oxford techniques? DeLorme ascends 50, 75, 100 per cent of 10RM; Oxford descends 100, 75, 50 per cent. ### Which contraction type generates the greatest force and the most soreness? Eccentric contraction — lengthening under load — producing both the highest tension and delayed onset muscle soreness. ### How many repetitions build strength versus endurance? About 8–12 heavy repetitions for strength; 15–25 lighter repetitions for endurance. ### Why are isometrics chosen immediately after surgery? They maintain neuromuscular activation and strength without joint movement or loading of healing tissue. ### What is 10RM? The heaviest load a patient can lift ten times through full range with correct form — the working unit of progressive resisted exercise.