Isometric exercise induces analgesia and reduces inhibition in patellar tendinopathy

Ebonie Rio, Dawson Kidgell, Craig Purdam, Jamie Gaida1, G Lorimer Moseley, Alan J Pearce, Jill Cook.
see original abstract BJSports Med online.

This single-blinded, randomised cross-over study compared immediate and 45 min effects following a bout of isometric and isotonic muscle contractions. Outcome measures were PT pain during the single-leg decline squat (SLDS, 0–10), quadriceps strength on maximal voluntary isometric contraction (MVIC).

Isometric pain decreased from seven (±2.04) on a 10-point scale to 0.17 (±.41). Isotonic exercise, on the other hand, reduced pain from 6.33 (±2.80) to 3.75 (±3.28).

The difference in pain reduction was statistically significant but the baseline differences between the two intervention groups were not, the study found. The paper goes on to discuss possible mechanisms and suggests local rather than central factors.