TY - JOUR

T1 - Motor responses to experimental Achilles tendon pain

AU - Henriksen, Marius

AU - Aaboe, Jens

AU - Graven-Nielsen, Thomas

AU - Bliddal, Henning

AU - Langberg, Henning

PY - 2011

Y1 - 2011

N2 - Background Achilles tendinopathies are characterised by pain and reduced function, and heavy-load exercises have been shown to be effective in the treatment of painful chronic Achilles tendinopathies. However, basic information is needed on how the biomechanics and neuromuscular control of the exercise are affected by Achilles tendon pain. Objective The authors aimed to determine the effects of experimental Achilles tendon pain on motor function during one-legged weight bearing ankle plantar and dorsal flexion exercises. Methods In a crossover study, with 16 healthy subjects tested on two different days separated by 1 week, three-dimensional ground reaction forces, ankle joint kinematics and surface electromyography (EMG) of the lower leg muscles were recorded during one-legged full weight-bearing ankle plantar (concentric) and dorsal (eccentric) flexion exercises. Measurements were done before, during and after either experimental Achilles tendon pain or a non-painful control condition. Pain was induced by intratendinous injections of hypertonic saline with isotonic saline injections as control. Joint kinematics, ground reaction force frequency contents and average EMG amplitudes were calculated. Results Compared with the control condition experimental Achilles tendon pain reduced the EMG activity in agonistic, synergistic and antagonistic muscles, and increased the ground reaction force frequency content around 10 Hz, during both eccentric and concentric movement phases. Conclusions These data show that experimental Achilles tendon pain causes widespread and reduced motor responses with functional effects on the ground reaction force.

AB - Background Achilles tendinopathies are characterised by pain and reduced function, and heavy-load exercises have been shown to be effective in the treatment of painful chronic Achilles tendinopathies. However, basic information is needed on how the biomechanics and neuromuscular control of the exercise are affected by Achilles tendon pain. Objective The authors aimed to determine the effects of experimental Achilles tendon pain on motor function during one-legged weight bearing ankle plantar and dorsal flexion exercises. Methods In a crossover study, with 16 healthy subjects tested on two different days separated by 1 week, three-dimensional ground reaction forces, ankle joint kinematics and surface electromyography (EMG) of the lower leg muscles were recorded during one-legged full weight-bearing ankle plantar (concentric) and dorsal (eccentric) flexion exercises. Measurements were done before, during and after either experimental Achilles tendon pain or a non-painful control condition. Pain was induced by intratendinous injections of hypertonic saline with isotonic saline injections as control. Joint kinematics, ground reaction force frequency contents and average EMG amplitudes were calculated. Results Compared with the control condition experimental Achilles tendon pain reduced the EMG activity in agonistic, synergistic and antagonistic muscles, and increased the ground reaction force frequency content around 10 Hz, during both eccentric and concentric movement phases. Conclusions These data show that experimental Achilles tendon pain causes widespread and reduced motor responses with functional effects on the ground reaction force.

KW - Achilles Tendon

KW - Biomechanics

KW - Cross-Over Studies

KW - Electromyography

KW - Female

KW - Humans

KW - Male

KW - Pain

KW - Psychomotor Performance

KW - Resistance Training

KW - Saline Solution, Hypertonic

KW - Tendinopathy

KW - Young Adult

U2 - 10.1136/bjsm.2010.072561

DO - 10.1136/bjsm.2010.072561

M3 - Journal article

C2 - 20542970

VL - 45

SP - 393

EP - 398

JO - British Journal of Sports Medicine

JF - British Journal of Sports Medicine

SN - 0306-3674

IS - 5

ER -