Experimental muscle pain during a forward lunge--the effects on knee joint dynamics and electromyographic activity.
OBJECTIVE
The purpose of this study was to investigate whether the knee joint dynamics during a forward lunge could be modulated by experimentally induced vastus medialis pain in healthy subjects.


METHODS
Randomised cross-over study.


METHODS
Biomechanical movement laboratory.


METHODS
20 healthy subjects were included. One subject was excluded during data collection.


METHODS
The subjects performed forward lunges before, during and 20 minutes after induction of experimental quadriceps muscle pain. Muscle pain was induced using hypertonic saline (5.8%) injected intramuscularly. Isotonic saline (0.9%) was used as control.


METHODS
Three-dimensional movement analyses were performed and inverse dynamics were used to calculate joint kinematics and kinetics for ankle, knee and hip joints. Electromyographic (EMG) signals of the hamstrings and quadriceps muscles were recorded.


RESULTS
During and after pain, significant decreases in knee joint dynamics and EMG recordings were observed.


CONCLUSIONS
The study shows that local pain in the quadriceps is capable of modulating movements with high knee joint dynamics. The results may have implications in the management of muscle pain and prevention of injuries during activities involving the knee joint.
Henriksen
M
M
Clinical Motor Function Laboratory, The Parker Institute, Frederiksberg Hospital, Ndr. Fasanvej 57, DK-2000 Frederiksberg, Denmark. marius.henriksen@frh.regionh.dk
Alkjaer
T
T
Simonsen
E B
EB
Bliddal
H
H
D000328:Adult; D001696:Biomechanical Phenomena; D018592:Cross-Over Studies; D004576:Electromyography; D005260:Female; D006801:Humans; D007552:Isotonic Solutions / Q000009:adverse effects; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D009068:Movement / Q000502:physiology*; D009135:Muscular Diseases / Q000503:physiopathology*; D010146:Pain / Q000503:physiopathology*; D052097:Quadriceps Muscle / Q000502:physiology*; D012462:Saline Solution, Hypertonic / Q000009:adverse effects
D007552:Isotonic Solutions; D012462:Saline Solution, Hypertonic