The Acute Effect of Isometric Versus Isotonic Resistance Exercise in Patients With Patellar Tendinopathy

NCT ID: NCT03528746

Last Updated: 2018-10-11

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 21 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2018-07-12
• Study Completion Date: 2018-10-03

Brief Summary

The purpose of this study is to compare the acute effects of two different types of resistance exercise (isometric versus isotonic) on exercise induced hypoalgesia during an aggravating activity, in participants with patellar tendinopathy.

Detailed Description

Exercise is a commonly prescribed treatment for patients with musculoskeletal pain, and is effective in treating tendon pain. It is well documented, that an acute bout of aerobic or resistance type exercise reduces sensitivity to pain in healthy individuals. Therefore the efficacy of exercise as an intervention may be partially due to the analgesic effect of exercise, also termed exercise-induced hypoalgesia (EIH).

For tendinopathies, high load resistance exercise is frequently used during rehabilitation.

However, the optimal mode and dosages required for reducing pain in patients with tendinopathies is unknown. Understanding the effect of different forms of exercise on pain may help optimize the prescription of exercise for pain management.

A recent study by Rio and colleagues documented the acute effect of two different forms of resistance exercise in patients with patellar tendinopathy. The study compared, isometric resistance exercise (static muscular contractions), in comparison to isotonic resistance exercise (dynamic contractions) and found that isometric exercise induced greater participantive pain relief in response to an aggravating task. This study was the first to compare the analgesic effect of different forms of resistance exercise in patients with tendinopathy.

Although the results appear promising, a limitation of the study was that it did not quantify the effect of the different exercises on measures of pain sensitivity as in previous studies examining EIH.

Purpose The purpose of this study is to compare the acute effects of two different types of resistance exercise (isometric versus isotonic) on exercise induced hypoalgesia during an aggravating activity, in participants with patellar tendinopathy.

Hypothesis The primary hypothesis is that isometric exercise will induce greater pain relief/reduction during an aggravating activity in comparison to isotonic exercises.

Study Design and Methods The proposed study is a participant blinded, randomised crossover superiority trial, to examine acute effect of isometric versus isotonic resistance exercise on pain in patients with patellar tendinopathy. The trial will be pre-registered on clinicaltrials.gov before inclusion of participants commences.

Conditions

Patellar Tendinitis

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: OTHER
• Blinding Strategy: SINGLE

Study Groups

Isometric exercise

Participants will complete isometric quadriceps exercise

Group Type: EXPERIMENTAL

Isometric exercise

Intervention Type: OTHER

Participants will complete isometric quadriceps exercise, where they must hold a load statically for 45s with their knee in 60° flexion. This will be repeated for 5 sets with 2 minutes rest between each set. A load of 70% of the maximal voluntary isometric contraction (MVIC) will be used. MVIC will be assessed in an isokinetic dynamometer as per Rio and colleagues. Participants will be seated in a stable position in the dynamometer with the knee at 60° of knee flexion. First they will be familiarised with the procedure. Standardised instructions will be issued for participants to perform a maximal effort knee extension against the dynamometer for 3seconds. After a short break, the test will be repeated three times and the MVIC will be peak torque recorded during these three efforts.

Isotonic exercise

Participants will complete dynamic leg extension

Group Type: ACTIVE_COMPARATOR

Isotonic Exercise

Intervention Type: OTHER

Participants will complete dynamic leg extension in a leg extension machine with a range of motion from approximately 90 degrees flexion to full extension. Each repetition will be completed with a 3s concentric contraction, 0s isometric and 4s eccentric contraction.This will be repeated for 8 repetitions and for 5 sets with 2 minutes rest between each set, as per Rio and colleagues. The load used during the isotonic exercise will be equivalent to participants 8 repetition maximum, which will be determined by an experienced tester in a standardised manner according to NSCA guidelines.

Interventions

Isotonic Exercise

Participants will complete dynamic leg extension in a leg extension machine with a range of motion from approximately 90 degrees flexion to full extension. Each repetition will be completed with a 3s concentric contraction, 0s isometric and 4s eccentric contraction.This will be repeated for 8 repetitions and for 5 sets with 2 minutes rest between each set, as per Rio and colleagues. The load used during the isotonic exercise will be equivalent to participants 8 repetition maximum, which will be determined by an experienced tester in a standardised manner according to NSCA guidelines.

Intervention Type: OTHER

Isometric exercise

Participants will complete isometric quadriceps exercise, where they must hold a load statically for 45s with their knee in 60° flexion. This will be repeated for 5 sets with 2 minutes rest between each set. A load of 70% of the maximal voluntary isometric contraction (MVIC) will be used. MVIC will be assessed in an isokinetic dynamometer as per Rio and colleagues. Participants will be seated in a stable position in the dynamometer with the knee at 60° of knee flexion. First they will be familiarised with the procedure. Standardised instructions will be issued for participants to perform a maximal effort knee extension against the dynamometer for 3seconds. After a short break, the test will be repeated three times and the MVIC will be peak torque recorded during these three efforts.

Intervention Type: OTHER

Other Intervention Names

resistance exercise

Eligibility Criteria

Inclusion Criteria

• Men and women aged 18-40 years, with patellar tendinopathy will be included. Diagnosis of patellar tendinopathy, will be made by a physiotherapist (who has been trained by an experienced rheumatologist) as follows, similar to previously outlined criteria:

• pain localised to the inferior pole of the patella during jumping and landing activities
• pain during testing on the single-leg decline squat (SLDS)
• The diagnosis will be confirmed by the presence of characteristic features on ultrasound imaging (eg, hypoechoic area and focal enlarged tendon).
• Minimum pain of 3cm on a 10cm visual analogue scale (VAS)
• Other concurrent diagnosable knee pathologies

Exclusion Criteria

• Previous surgery of the knee
• Pregnancy
• Corticosteroid injection within the previous 6 months

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 40 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Aalborg University

OTHER

Sponsor Role: lead

Responsible Party

Sinead Holden

Post- Doctoral Research Fellow

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Research Unit for General Practice in Aalborg

Aalborg, , Denmark

Countries

Denmark

References

Rio E, Kidgell D, Purdam C, Gaida J, Moseley GL, Pearce AJ, Cook J. Isometric exercise induces analgesia and reduces inhibition in patellar tendinopathy. Br J Sports Med. 2015 Oct;49(19):1277-83. doi: 10.1136/bjsports-2014-094386. Epub 2015 May 15.

Reference Type: BACKGROUND

PMID: 25979840 (View on PubMed)

Other Identifiers

N-20160084

Identifier Type: -

Identifier Source: org_study_id