Experimental knee joint pain during strength training and muscle strength gain in healthy subjects: a randomized controlled trial

TY - JOUR

T1 - Experimental knee joint pain during strength training and muscle strength gain in healthy subjects

T2 - a randomized controlled trial

AU - Sørensen, T J

AU - Langberg, Henning

AU - Hodges, P W

AU - Bliddal, H

AU - Henriksen, M

N1 - Copyright © 2012 by the American College of Rheumatology.

PY - 2012/1

Y1 - 2012/1

N2 - Objective. Knee joint pain and reduced quadriceps strength are cardinal symptoms in many knee pathologies. In people with painful knee pathologies, quadriceps exercise reduces pain, improves physical function, and increases muscle strength. A general assumption is that pain compromises muscle function and thus may prevent effective rehabilitation. This study evaluated the effects of experimental knee joint pain during quadriceps strength training on muscle strength gain in healthy individuals. Methods. Twenty-seven healthy untrained volunteers participated in a randomized controlled trial of quadriceps strengthening (3 times per week for 8 weeks). Participants were randomized to perform resistance training either during pain induced by injections of painful hypertonic saline (pain group, n = 13) or during a nonpainful control condition with injection of isotonic saline (control group, n = 14) into the infrapatellar fat pad. The primary outcome measure was change in maximal isokinetic muscle strength in knee extension/flexion (60, 120, and 180 degrees/second). Results. The group who exercised with pain had a significantly larger improvement in isokinetic muscle strength at all angular velocities of knee extension compared to the control group. In knee flexion there were improvements in isokinetic muscle strength in both groups with no between-group differences. Conclusion. Experimental knee joint pain improved the training-induced gain in muscle strength following 8 weeks of quadriceps training. It remains to be studied whether knee joint pain has a positive effect on strength gain in patients with knee pathology.

AB - Objective. Knee joint pain and reduced quadriceps strength are cardinal symptoms in many knee pathologies. In people with painful knee pathologies, quadriceps exercise reduces pain, improves physical function, and increases muscle strength. A general assumption is that pain compromises muscle function and thus may prevent effective rehabilitation. This study evaluated the effects of experimental knee joint pain during quadriceps strength training on muscle strength gain in healthy individuals. Methods. Twenty-seven healthy untrained volunteers participated in a randomized controlled trial of quadriceps strengthening (3 times per week for 8 weeks). Participants were randomized to perform resistance training either during pain induced by injections of painful hypertonic saline (pain group, n = 13) or during a nonpainful control condition with injection of isotonic saline (control group, n = 14) into the infrapatellar fat pad. The primary outcome measure was change in maximal isokinetic muscle strength in knee extension/flexion (60, 120, and 180 degrees/second). Results. The group who exercised with pain had a significantly larger improvement in isokinetic muscle strength at all angular velocities of knee extension compared to the control group. In knee flexion there were improvements in isokinetic muscle strength in both groups with no between-group differences. Conclusion. Experimental knee joint pain improved the training-induced gain in muscle strength following 8 weeks of quadriceps training. It remains to be studied whether knee joint pain has a positive effect on strength gain in patients with knee pathology.

KW - Adult

KW - Arthralgia

KW - Biomechanics

KW - Denmark

KW - Female

KW - Humans

KW - Injections, Intra-Articular

KW - Knee Joint

KW - Male

KW - Muscle Strength

KW - Pain Measurement

KW - Quadriceps Muscle

KW - Resistance Training

KW - Saline Solution, Hypertonic

KW - Time Factors

KW - Torque

KW - Treatment Outcome

KW - Young Adult

U2 - 10.1002/acr.20618

DO - 10.1002/acr.20618

M3 - Journal article

C2 - 21905254

SN - 2151-464X

VL - 64

SP - 108

EP - 116

JO - Arthritis Care & Research

JF - Arthritis Care & Research

IS - 1

ER -