Reactive Strength, Calf Endurance, Running Gait and Imaging

Reactive strength is tested with a single leg 10-5 repeated hop, aiming for ground contact under 0.25 seconds and a reactive strength index above 0.5, and with the single leg rebound test credited to Colin Griffin, which measures horizontal propulsion over a hurdle. A good rebound distance is 75 to 100% of body height. The MyJump app is a low-cost alternative to force plates. The single leg calf raise to fatigue uses a metronome at 60 beats per minute and a ruler to set height. Runners should reach at least 25 reps, 30 or more at a higher level, with less than 10% asymmetry. Brady Green found controlling technique cut about 12 reps, so watch for knee flexion, hip hiking, trunk rocking and rolling to the lateral foot. Assessment should extend to the foot and proximal chain. In gait, a forefoot strike, overstriding, longer ground contact, pelvic drop and anterior tilt are linked to calf problems. Imaging can confirm the injury but rarely changes a criteria-driven rehabilitation plan.