Introduction: The weakness of quadriceps femoris muscle is a common occurrence after
rupture and reconstruction of the anterior cruciate ligament. Muscle atrophy and reduced
ability of voluntary activation substantially contribute to the muscle weakness. Reduced
muscle activation occurs due to a decrease in central inflows to the muscle resulting from
changes in spinal-reflex and corticospinal neural pathways. Reduced central muscle
activation should primarily be the protective mechanism of the body against further
injuries, but unfortunately it prevents effective rehabilitation and return to activity or sport.
It also persists for several years after the injury. Purpose: To determine the effect of
rehabilitation and appropriate therapeutic procedures on the change in central activation
and inhibition of quadriceps femoris muscle in individuals after anterior cruciate ligament
injury. Methods: The method that we used was a systematic review of technical and
scientific literature. The literature search was conducted in the PubMed database using
keywords. Results: We have included eight articles. Four studies observed a change in the
central activation of quadriceps according to a general rehabilitation protocol, while four
studies observed a change according to specific physiotherapeutic protocols. The results of
studies where the general rehabilitation protocol was used are quite different, even
contradictory. Some studies have found improvement in central muscle activation after
rehabilitation, while some have found its decrease. Results of studies that investigated the
effect of specific physiotherapeutic protocols indicate high efficacy of eccentric exercise in
patients with a deficiency in central muscle activation after anterior cruciate ligament
rupture. Considerable improvements in central muscle activation were also measured after
therapies where combinations of physiotherapy procedures, such as cryotherapy before
exercise and transcutaneous electrical nerve stimulation (TENS) during exercise, were
used. Unfortunately in the latter two protocols authors did not measure statistically
significant differences compared to mere exercise, but the difference is clinically relevant.
Discussion and conclusion: In order to improve muscle strength and central activation of
quadriceps femoris muscle in individuals after anterior cruciate ligament rupture a
rehabilitation or physiotherapeutic program is proposed to include eccentric exercise,
cryotherapy before exercise or transcutaneous electrical nerve stimulation (TENS) during
exercise. For more solid findings greater number of studies should be included in the
literature review. The need for further studies that would investigate the effect of certain
physiotherapy procedures in subjects after anterior cruciate ligament rupture still remains.
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