Table 5 Examples of screening and monitoring options for risk of future calf muscle strain injuries
Domain | Outcome of interest | Tests and example benchmarks |
|---|---|---|
Non-modifiable intrinsic factors | Injury history | History of CMSI; other injury history or current sub-clinical state: foot (1st MTPJ, plantar fascia, bone stress, fractures), ankle (sprains, fractures, Achilles), knee, lumbar spine, other muscle strains (hamstring, quadriceps, adductor), including history of recurrent injuries; ethnicity |
Chronological age | Age: years | |
Body mass index | kg m2 | |
Range of motion and tissue extensibility | Weight bearing dorsiflexion Posterior extensibility | Knee-to-wall lunge test: Range of motion (cm); asymmetry ≤ 10% Standing flexion, or sit-and-reach test |
Isolated calf strength | Foundation strength-endurance | Single leg calf raise test: capacity (repetitions to fatigue ≥ 30), asymmetry ≤ 10%, movement quality/ coordination. Metronome paced (30 beats/ minute); performed from the floor* to fatigue + / − a cut-off |
Loaded strength | Smith and/or seated calf machines: ideal relative strength benchmarks ≥ 1.0xBW for knee extended (0°) and ≥ 1.5xBW for knee flexed (90°); asymmetries ≤ 10%. Various RM regimes pending sport (1RM-8RM) | |
Power capacities and function during dynamic activities | Vertical | Single leg drop jump or single leg CMJ: total height (cm), reactive strength index, early RFD, late RFD, eccentric impulse; asymmetries ≤ 10%; movement quality/ coordination |
Horizontal | Forward hop test: distance (m); asymmetry ≤ 10%; movement quality/ coordination. Measured using a single or multiple hops ≥ 3, or as single-leg bound in high-level athletes; 20 m prowler sprint test | |
Exposure history | Recent | Details of any interruptions to usual exposure; details of recent program: velocities, volumes, exposure to specialised activities of the sport (multi-axial, acceleration, deceleration, metabolic), GPS data |
Medium–long term | Workload data; training age (i.e. number of years playing sport, completing on-field and off-field strength and conditioning activities/ exercises); GPS data; preseason completeness > 80% | |
Loading conditions | Running surfaces; footwear; orthotics |