вход по аккаунту


Electromyography of pectineus muscle.

код для вставкиСкачать
Electromyography of Pectineus Muscle
Regional Rehabilitation Research and Training Center and Department of
Anatomy, Emory University, Atlanta, Georgia
Using bipolar fine-wire electrodes, we investigated the function
of the pectineus muscle. Electromyography revealed that the main function of
pectineus muscle is flexion, adduction and medial (not lateral) rotation of the
hip joint. These functions suggest that the spasm of this muscle may be important in the cause of deformities in cerebral palsy.
Modern electromyographic studies on
the muscles around the hip joint have
neglected the role of the pectineus muscle
because of its inaccessibility and the proximity to femoral vessels. Most authors
agree that it flexes and adducts the hip
joint. However, some textbooks (e.g.
Woodburne, '65) state that pectineus is
mainly an adductor, while Duchenne
(1867) and Wells ('69) gave flexion as
its main function. Other possible functions have been suggested sporadically and
with little or no confirmation. Goss ('69),
among others, stated that pectineus rotates
the hip medially, although Edwards ('56)
and Woodburne accepted the view of
Duchenne who believed the opposite.
Clinical views of the muscle and its
neighbors make it of greater importance
than its small size would suggest. Lamb
and Pollock ('62) offered iliopsoas and
pectineus overactivity as a primary cause
of the flexion deformity of the hip joint
in children with cerebral palsy.
Prompted by these divergent anatomical
opinions and growing clinical interest, we
undertook a limited electromyographic investigation of the function of the pectineus
muscle. Dissections demonstrated the feasibility of percutaneously implanting electrodes without special risk. The pectineus
is a thin quadrangular muscle which is the
highest adductor. It arises from the superior ramus of the pubis and runs downward, backward and lateralward to insert
into a rough line that descends from the
lesser trochanter.
Two of the investigators acted as subANAT. REC.,180: 281-284.
jects. The bipolar fine-wire electrodes (Basmajian and Stecko, '62) were inserted
upwards and medially into the muscle 2
cm lateral to the public tubercle and 3 cm
below the inguinal ligament. (The needle
is removed leaving the 25-micron wires in
situ for the duration of experiments.) Action potentials were amplified and recorded
on FM magnetic tape. Simultaneously both
subject behavior and muscle activity were
videotaped by split-screen methods for
later validation of results. Records were
made according to a protocol in the standing and supine positions and during walking. Foot contact-switches were used to
record the heel- and toe-strikes during
Moderate or marked activity of the muscle occurred equally in free flexion, adduction and medial rotation. Against resistance these movements showed much
greater activity than the free movements.
Each of these resisted isometric efforts and
free movements showed much more activity when the hip was at 90 degrees of
flexion compared with when it was extended or slightly flexed.
Neglible or nil activity occurred in both
free lateral rotation and the same movement against resistance. Neither was activity recorded during quiet sitting, standing
on both feet, and standing on the ipsilatReceived Jan. 25, '74. Accepted Mar. 26, '74.
1 On leave of absence from the Department of Orthopedic Surgery, Kobe University School of Medicine,
Kobe, Japan.
2 On leave of absence from the Department of Morphology, Faculdade de Odontologia de Piracicaba,
U.E.C.,Siio Paulo, B r a d . Fellowship from FundaqHo
de Amparo B Pesquisa do Estado de SZo Paulo, Proc.
med. 71/1045.
Fig. 1 EMG of the pectineus, showing marked activity in flexion (tracing 2) adduction
(3) and medial rotation ( 4 ) of the hip, but none in lateral rotation (1).
eral foot. Sit-ups from the supine position
showed slight activity, but flexion of the
trunk in the standing position did not. During normal walking, moderate activity was
recorded in the stance phase from the
middle of heel strike to the end of toe
strike; and slight activity was noted during the swing phase.
the swing phase. Finally, our findings suggest that contracture or spasticity of this
muscle could be a cause of the deformity
of the hip joint in children with cerebral
pdsy-which typically is flexion, adduction and
We are grateful to Mr. James Perry for
technical assistance.
Our results show that this muscle participates equally in flexion, adduction and
medial rotation of the hip. They contradict
those authors who have surmised from its
morphology that its function is lateral rotation. We believe that in walking the pectineus works as a stabilizer and possible
medial rotator of the hip in the stance
phase, and contributes to flexion during
Basmajian, J. V., and G. A. Stecko 1962 A
new bipolar indwelling electrode for electromyography. J. Appl. Physiol., 17: 849.
Bleck, E. E. 1972 Postural and gait abnormalities caused by hip-flexion deformity in spastic
cerebral palsy. J. Bone and Joint Surg., 53-A:
Duchenne, G. B. 1867 Physiology of Motion.
Translated by E. B. Kaplan ('59) Philadelphia
W. B. Saunders, p. 266.
Edwards, L. E. 1956 Concise Anatomy, 2nd
ed. McGraw-Hill Book Co., New York, p. 191.
Goss, C. M. 1969 Gray's Anatomy of the
Human Body. 28th ed., Lea and Febiger, Philadelphia, p. 498.
Lamb, D. W., and G. A. Pollock 1962 Hip
deformities in cerebral palsy and their treatment. Develop. Med. Child. Neural., 4: 488498.
Wells, W. F. 1969 Kinesiology, 4th ed., W. B.
Saunders, Philadelphia, p. 310.
Woodburne, R. T. 1965 Essentials of Human
Anatomy, 3rd ed., Oxford Univ. Press, New
York, p. 579.
Без категории
Размер файла
159 Кб
muscle, pectineus, electromyography
Пожаловаться на содержимое документа