Premium
Inhibition of dynamic thigh muscle contraction by electrical stimulation of the posterior cruciate ligament in humans
Author(s) -
FischerRasmussen Torsten,
Krogsgaard Michael,
Jensen Dennis Bo,
DyhrePoulsen Poul
Publication year - 2001
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.1172
Subject(s) - biceps , biceps femoris muscle , vastus medialis , anatomy , stimulation , medicine , reflex , thigh , electromyography , contraction (grammar) , electrical muscle stimulation , muscle contraction , muscle belly , isometric exercise , anterior cruciate ligament , quadriceps femoris muscle , concentric , tendon , anesthesia , physical medicine and rehabilitation , geometry , mathematics
We investigated the influence of electrical stimulation of the posterior cruciate ligament (PCL) on the motoneuron pool of the thigh muscle during voluntary static and dynamic muscle contraction. The study group comprised nine young men with no history of injury to the knee joints. Multistranded Teflon‐insulated stainless‐steel wires were inserted into the PCL guided by ultrasound. In three subjects wires were also inserted into the fat pad of the knee. The PCL was electrically stimulated during static, concentric, or eccentric muscle contraction with a constant load of 20% of the maximal voluntary contraction of either the quadriceps or the hamstrings. Electromyographic signals were recorded with bipolar surface electrodes placed over the vastus medialis, rectus femoris, vastus lateralis, biceps femoris caput longum, and semitendinosus muscles. The stimuli consisted of four pulses delivered at 200 H Z ; the stimulus amplitude was two to three times the sensory threshold. The electrical stimulation of the PCL inhibited the ongoing muscle activity in both the quadriceps and hamstrings with latencies of 114–150 ms and 99–130 ms, respectively. Stimulation of the fat pad of the knee did not influence the muscle activity. The study suggests that the mechanoreceptors in the PCL are involved in controlling muscle activity during both static and active muscle contractions. The relative long latency of the reflex makes it unlikely that it can serve as a directly protective reflex for the cruciate ligaments. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1482–1488, 2001