Patellar Tendinopathy (Jumper's Knee)

Pain appears when jumping volume increases faster than the tendon can adapt — a new season, a change of surface, a growth spurt. The tendon is not torn; it is under-prepared for what is being asked of it.

Imaging findings correlate poorly with symptoms. Tendons that look abnormal on ultrasound are found in athletes with no pain at all; such changes raise the risk of symptoms later, roughly fourfold in pooled studies 3, but they do not show what the tendon can tolerate today, so scans are not used to decide whether an athlete can play.

It moves through four stages: isometric holds as a well-tolerated first load, slow strengthening against increasing load, energy-storage exercise, and finally return to sport-specific jumping and landing 1. Isometrics were once thought to relieve pain immediately, but well-designed studies have not confirmed that effect 1. Each stage is entered on criteria, not on weeks elapsed.

Some pain during loading is acceptable and expected; the rule is that it settles afterwards rather than building from one day to the next. Training through worsening morning pain is what turns a manageable tendon into a season-ending one.

Corticosteroid injection into the patellar tendon: in a randomised trial its early relief had faded by six months 2, and rupture has been reported after repeated injections 5. Complete rest, which reduces capacity further. And passive treatment alone — shockwave and similar modalities may help alongside loading but replace nothing; used on its own during the competitive season, shockwave was no better than a sham treatment 4.

The tendon is loaded every time the athlete jumps and lands, and pain in this condition often permits continued play. Recovery while competing is slow: in a trial of athletes who kept playing through the season, symptom scores improved only modestly over 22 weeks 4.

Management is therefore about controlling the total load rather than resting: reducing jumping volume while adding heavy slow resistance work, over months rather than weeks.

A 2021 randomised trial compared progressive tendon loading with eccentric decline squats in 76 athletes whose symptoms had lasted a median of two years 1. After 24 weeks, the progressive programme improved the VISA-P score, a 0–100 measure of pain, function and ability to play sport, by 28 points against 18, and its exercises hurt less to perform 1. An earlier, smaller trial found that heavy slow resistance training held its benefit at six months, while the early relief from a corticosteroid injection faded 2. Adherence was modest in both arms of the larger trial, and its authors suggested supervision might improve results 1.

When loading no longer provokes more than mild pain, rather than on a set date. In the progressive programme above, each stage began only after the previous one had been done for at least a week and a single-leg squat hurt no more than 3 out of 10, and return to competition was advised once sport-specific drills stayed within that limit 1. Activities that caused considerable tendon pain were cut back or avoided for at least four weeks while the programme progressed 1. Expectations need to be realistic: even so, only 43% were back in their sport at pre-injury level after 24 weeks 1.