Evidence of widespread mechanical hyperalgesia but not exercise induced analgesia in athletes with mild patellar tendinopathy compared to pain-free matched controls:a blinded exploratory study

OBJECTIVE: To assess centrally induced pain processing with pressure pain thresholds (PPT) bilaterally and remotely in active volleyball and basketball athletes with mild patellar tendinopathy compared to asymptomatic control athletes. Secondary objective was to explore the role of exercised induced analgesia during a training session in athletes with patellar tendinopathy. DESIGN: In this exploratory study, PPTs of 21 patellar tendinopathy athletes and 16 age and sex matched asymptomatic team members were measured by a blinded assessor bilaterally on the patellar tendon and unilaterally on the elbow extensor tendon with a pressure algometer before, during and after a regular training session. RESULTS: Patellar tendinopathy athletes had a significantly higher average body mass index compared to asymptomatic athletes (mean difference 1.75 (95%CI 0.35, 3.15), p= 0.02). At baseline, athletes with patellar tendinopathy showed lowered PPTs in the affected knee (p=0.001), unaffected knee (p<0.001), and elbow (p=0.01) compared to controls. No clear patterns were identified to explain between group differences in PPTs before, during and after exercise. CONCLUSION: This exploratory study found primary and secondary mechanical hyperalgesia in athletes with patellar tendinopathy compared asymptomatic athletes. Further research is required on the effects of an acute exercise bout on pain thresholds in this population