Estimate return-to-sport time after injury.
Return-to-sport timelines are driven by the tissue involved and the grade of the injury, not by how quickly pain settles. A grade 1 muscle strain typically takes two to three weeks, a grade 2 partial tear six or more, and a complete tear three months or longer, while tendinopathy is measured in months because tendon remodels far more slowly than muscle. Three things then modify it. Healing slows with age as tissue turnover and blood supply decline. A previous injury at the same site raises the timeline substantially, since recurrence usually indicates the first episode was never fully rehabilitated. And adherence matters more than any other controllable factor, because loading progression is the treatment rather than an optional extra. Crucially, the decision to return should be criterion-based — full pain-free range and symmetrical strength — with the calendar as a guide rather than the test.
Modified return-to-sport estimate
Weeks = base weeks x age factor x recurrence factor x adherence factor, where age factor = 1 + 0.009 x (age - 25), recurrence = 1.3 if the same injury has occurred before, and adherence factor = 1 / (0.65 + 0.35 x compliance / 100)
This is a population-level estimate and absolutely not a diagnosis, treatment plan or medical advice. Injuries that look similar can differ greatly, and returning to sport too early causes re-injury. Any suspected fracture, joint instability, numbness, inability to bear weight, or pain that is not improving must be assessed by a qualified clinician.
No. Pain resolves well before tissue regains its tensile strength, which is why re-injury rates peak in the first weeks back. Return should be decided on pain-free full range and strength within about ten percent of the other side, not on comfort.
Because recurrence usually means the original rehabilitation stopped at pain resolution rather than at restored strength and control. The tissue carries scar and a strength deficit, both of which lengthen the second recovery.
Tendon has poor blood supply and a very slow collagen turnover, so remodelling takes months. It also responds to progressive loading rather than rest — immobilising a tendinopathy typically makes it worse.