Isometric contractions vs isotonic contractions analgesia for patellar tendon pain
A study has been done to compare the immediate analgesic effects of 2 resistance programs in in-season athletes with patellar tendinopathy (PT). Resistance training is noninvasive, a fundamental stimulus for corticospinal and neuromuscular adaptation, and may be analgesic. Data analysis was performed blinded to group including the subelite volleyball and basketball competitions.
Overall 20 jumping athletes aged more than 16 years were included who participated in games/trainings 3 times per week with clinically diagnosed PT. Two quadriceps resistance protocols were differentiated; (1) isometric leg extension holds at 60-degree knee flexion (80% of their maximal voluntary isometric contraction) or (2) isotonic leg extension (at 80% of their 8 repetition maximum) 4 times per week for 4 weeks. Between groups, the time under load and rest between sets was matched.
The prime outcome measures were: Pain (0-10 numerical rating score) during single leg decline squat (SLDS), measured preintervention and postintervention sessions. VISA-P, a questionnaire about tendon pain and function, finished at baseline and after 4 weeks. Total 20 athletes with PT (18 men, mean 22.5 +/- 4.7 years) were engaged (isotonic n = 10, isometric n = 10). Baseline median SLDS pain was 5/10 for both groups (isotonic range 1-8, isometric range 2-8). Isometric contractions generated significantly enhanced immediate analgesia (P < 0.002). Week one analgesic response positively correlated with augmentation in VISA-P at 4 weeks (r2 = 0.64).
Both protocols appeared efficacious for in-season athletes to reduce pain, however, isometric contractions demonstrated remarkably greater immediate analgesia throughout the 4-week trial. Greater analgesia may enhance the ability to load or perform.