title: Do isometric and isotonic exercise programs reduce pain in athletes with patellar tendinopathy in-season? A randomised clinical trial.
abstract: OBJECTIVE
  Many athletes with patellar tendinopathy participate in sports with symptoms during or after activities. Current treatments do not decrease pain in-season; eccentric exercises in-season result in an increase in pain. This study examined if isometric and isotonic exercises relieved pain in competing athletes with patellar tendinopathy.
  
  
  METHODS
  Randomised clinical trial.
  
  
  METHODS
  Jumping athletes with patellar tendinopathy playing at least three times per week participated in this study. Athletes were randomised into an isometric or isotonic exercise group. The exercise programs consisted of four isometric or isotonic exercise sessions per week for four weeks. Pain during a single leg decline squat (SLDS) on a Numeric Rating Scale (NRS; 0-10) was used as the main outcome measure; measurements were completed at baseline and at 4-week follow-up.
  
  
  RESULTS
  Twenty-nine athletes were included in this study. Median pain scores improved significantly over the 4-week intervention period in both the isometric group (Z=-2.527, p=0.012, r=-0.63) and isotonic group (Z=-2.952, p=0.003, r=-0.63). There was no significant difference in NRS pain score change (U=29.0, p=0.208, r=0.29) between the isometric group (median (IQR), 2.5 (1-4.5)) and isotonic group (median (IQR), 3.0 (2-6)).
  
  
  CONCLUSIONS
  This is the first study to show a decrease in patellar tendon pain without a modification of training and competition load and the first study to investigate isometric exercises in a clinical setting. Both isometric and isotonic exercise programs are easy-to-use exercises that can reduce pain from patellar tendinopathy for athletes in-season.
authors.affiliation: University of Groningen, University Medical Center Groningen, Center for Sports Medicine, The Netherlands; Monash University, School of Physiotherapy, Australia. Electronic address: m.van.ark@pl.hanze.nl.
authors.forename: Mathijs
authors.initials: M
authors.lastname: van Ark
authors.affiliation: Monash University, School of Physiotherapy, Australia.
authors.forename: Jill L
authors.initials: JL
authors.lastname: Cook
authors.affiliation: Monash University, School of Physiotherapy, Australia.
authors.forename: Sean I
authors.initials: SI
authors.lastname: Docking
authors.affiliation: University of Groningen, University Medical Center Groningen, Center for Sports Medicine, The Netherlands.
authors.forename: Johannes
authors.initials: J
authors.lastname: Zwerver
authors.affiliation: Monash University, School of Physiotherapy, Australia; University of Canberra, Discipline of Physiotherapy University Drive, Australia.
authors.forename: James E
authors.initials: JE
authors.lastname: Gaida
authors.affiliation: University of Groningen, University Medical Center Groningen, Center for Sports Medicine, The Netherlands.
authors.forename: Inge
authors.initials: I
authors.lastname: van den Akker-Scheek
authors.affiliation: Monash University, School of Physiotherapy, Australia.
authors.forename: Ebonie
authors.initials: E
authors.lastname: Rio
mesh_terms: D000293:Adolescent; D000328:Adult; D001490:Basketball / Q000293:injuries*; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007551:Isotonic Contraction / Q000502:physiology*; D008297:Male; D010147:Pain Measurement; D017847:Patellar Ligament / Q000293:injuries*; D018709:Statistics, Nonparametric; D052256:Tendinopathy / Q000628:therapy*; D054798:Volleyball / Q000293:injuries*; D055815:Young Adult
keywords: Exercise therapy; Jumper's knee; Patellar ligament; Physical therapy modalities; Tendinopathy; Tendons