The action of muscles, including muscle rest and muscle re-education,

Bibliographical footnotes.

A compendious system of anatomy : In six parts. Part I. Osteology. II. Of the muscles, &c. III. Of the abdomen. Part IV. Of the thorax. V. Of the brain and nerves. VI. Of the senses. From the Encyclopaedia. Illustrated with twelve large copperplates.

Austin

The anatomy and physiology of the human body : containing The anatomy of the bones, muscles, and joints, and the heart and arteries /

Earlier eds. have title: The anatomy of the human body.

Local analgesia: abdominal surgery,

Mode of access: Internet.

External perturbation of the trunk in standing humans differentially activates components of the medial back muscles

During voluntary arm movements, the medial back muscles are differentially active. It is not known whether differential activity also occurs when the trunk is perturbed unpredictably, when the earliest responses are initiated by short-latency spinal mechanisms rather than voluntary commands. To assess this, in unpredictable and self-initiated conditions, a weight was dropped into a bucket that was held by the standing subject (n = 7). EMG activity was recorded from the deep (Deep MF), superficial (Sup MF) and lateral (Lat MF) lumbar multifidus, the thoracic erector spinae (ES) and the biceps brachii. With unpredictable perturbations, EMG activity was first noted in the biceps brachii, then the thoracic ES, followed synchronously in the components of the multifidus. During self-initiated perturbations, background EMG in the Deep MF increased two- to threefold, and the latency of the loading response decreased in six out of the seven subjects. In Sup MF and Lat MF, this increase in background EMG was not observed, and the latency of the loading response was increased. Short-latency reflex mechanisms do not cause differential action of the medial back muscles when the trunk is loaded. However, during voluntary tasks the central nervous system exerts a 'tuned response', which involves discrete activity in the deep and superficial components of the medial lumbar muscles in a way that varies according to the biomechanical action of the muscle component.

Getting muscles moving again after botulinum toxin: novel therapeutic challenges

The use of botulinum neurotoxins for the treatment of muscle hyperactivity and spasticity disorders has been remarkably successful, owing to the abilities of the toxins to elicit prolonged localized paralysis and the rarity of serious adverse effects. However, botulinum toxins are the most deadly protein toxins known, and existing antidotes possess limited effectiveness. Paradoxically, in situ, the intoxicated motoneuron does not die. It reacts by emanating a sprouting network known to implement new functional synapses, leading to resumption of neurotransmission. Recent studies have highlighted ways of accelerating this natural recovery process to overcome paralysis successfully. Developing new therapeutic strategies and treatments for botulism will require more research into the molecular understanding of this 'naturally occurring' recovery process.

Neuromuscular efficiency of the sternocleidomastoid and anterior scalene muscles in patients with chronic neck pain

Purpose: This study compared the neuromuscular efficiency (NME) of the sternocleidomastoid (SCM) and anterior scalene (AS) muscles between 20 chronic neck pain patients and 20 asymptomatic controls. Method: Myoelectric signals were recorded from the sternal head of SCM and the AS muscles as subjects performed sub-maximal isometric cervical flexion contractions at 25 and 50% of the maximum voluntary contraction (MVC). The NME was calculated as the ratio between MVC and the corresponding average rectified value of the EMG signal. Ultrasonography was used to measure subcutaneous tissue thickness over the SCM and AS to ensure that differences did not exist between groups. Results: For both the SCM and AS muscles, NME was shown to be significantly reduced in patients with neck pain at 25% MVC (p < 0.05). Subcutaneous tissue thickness over the SCM and AS muscles was not different between groups. Conclusions: Reduced NME in the superficial cervical flexor muscles in patients with neck pain may be a measurable altered muscle strategy for dysfunction in other muscles. This aberrant pattern of muscle activation appears to be most evident under conditions of low load. NME, when measured at 25% MVC, may be a useful objective measure for future investigation of muscle dysfunction in patients with neck pain.

Feedforward activity of the cervical flexor muscles during voluntary arm movements is delayed in chronic neck pain

The objective of this study was to compare onset of deep and superficial cervical flexor muscle activity during rapid, unilateral arm movements between ten patients with chronic neck pain and 12 control subjects. Deep cervical flexor (DCF) electromyographic activity (EMG) was recorded with custom electrodes inserted via the nose and fixed by suction to the posterior mucosa of the oropharynx. Surface electrodes were placed over the sternocleidomastoid (SCM) and anterior scalene (AS) muscles. While standing, subjects flexed and extended the right arm in response to a visual stimulus. For the control group, activation of DCF, SCM and AS muscles occurred less than 50 ms after the onset of deltoid activity, which is consistent with feedforward control of the neck during arm flexion and extension. When subjects with a history of neck pain flexed the arm, the onsets of DCF and contralateral SCM and AS muscles were significantly delayed (p<0.05). It is concluded that the delay in neck muscle activity associated with movement of the arm in patients with neck pain indicates a significant deficit in the automatic feedforward control of the cervical spine. As the deep cervical muscles are fundamentally important for support of the cervical lordosis and the cervical joints, change in the feedforward response may leave the cervical spine vulnerable to reactive forces from arm movement.

Patients with neck pain demonstrate reduced electromyographic activity of the deep cervical flexor muscles during performance of the craniocervical flexion test

Study Design. Cross-sectional study. Objective. The present study compared activity of deep and superficial cervical flexor muscles and craniocervical flexion range of motion during a test of craniocervical flexion between 10 patients with chronic neck pain and 10 controls. Summary of Background Data. Individuals with chronic neck pain exhibit reduced performance on a test of craniocervical flexion, and training of this maneuver is effective in management of neck complaints. Although this test is hypothesized to reflect dysfunction of the deep cervical flexor muscles, this has not been tested. Methods. Deep cervical flexor electromyographic activity was recorded with custom electrodes inserted via the nose and fixed by suction to the posterior mucosa of the oropharynx. Surface electrodes were placed over the superficial neck muscles ( sternocleidomastoid and anterior scalene). Root mean square electromyographic amplitude and craniocervical flexion range of motion was measured during five incremental levels of craniocervical flexion in supine. Results. There was a strong linear relation between the electromyographic amplitude of the deep cervical flexor muscles and the incremental stages of the craniocervical flexion test for control and individuals with neck pain ( P = 0.002). However, the amplitude of deep cervical flexor electromyographic activity was less for the group with neck pain than controls, and this difference was significant for the higher increments of the task ( P < 0.05). Although not significant, there was a strong trend for greater sternocleidomastoid and anterior scalene electromyographic activity for the group with neck pain. Conclusions. These data confirm that reduced performance of the craniocervical flexion test is associated with dysfunction of the deep cervical flexor muscles and support the validity of this test for patients with neck pain.

The management of extra-abdominal desmoid tumours

We performed a retrospective analysis of 35 cases of desmoid tumours (aggressive fibromatoses) that underwent treatment at our institutions between 1987 and 2002. The purpose was to evaluate the rate of local recurrence of desmoid tumours treated with surgical excision, to assess the impact of surgical margins on local recurrence and to define the role of radiotherapy in the treatment. Nine patients experienced a recurrence at an average of 16 months after initial treatment. Seven of the 15 patients with a less-than-wide margin had a local recurrence. Comparatively, only two of the 20 patients with a wide margin had a local recurrence. Thirty-three of the 35 patients were disease free at the last follow-up. We recommend wide excision with clear margins whenever possible. Marginal resections are appropriate when wide excision would severely compromise the function of the limb. Surgical resections and selective supplementation of adjuvant radiotherapy give excellent control rates.

A new method of isometric dynamometry for the craniocervical flexor muscles

Background and Purpose. A new method of dynamometry has been developed to measure the performance of the craniocervical (CC) flexor muscles by recording the torque that these muscles exert on the cranium around the CC junction. This report describes the method, the specifications of the instrument, and the preliminary reliability data. Subjects and Methods. For the reliability study, 20 subjects (12 subjects with a history of neck pain, 8 subjects without a history of neck pain) performed, on 2 occasions, maximal voluntary isometric contraction (MVIC) tests of CC flexion in 3 positions within the range of CC flexion and submaximal sustained tests (20% and 50% of MVIC) in the middle range of CC flexion (craniocervical neutral position). Reliability coefficients were calculated to establish the test-retest reliability of the measurements. Results. The method demonstrated good reliability over 2 sessions in the measurement of MVIC (intraclass correlation coefficient [ICC] =.79-.93, SEM=0.6-1.4 N-m) and in the measurement of steadiness (standard deviation of torque amplitude) of a sustained contraction at 20% of NMC (ICC=.74-.80, SEM=0.01 N-m), but not at 50% of MVIC (ICC=.07-.76, SEM=0.04-0.13 N-m). Discussion and Conclusion. The new dynamometry method appears to have potential clinical application in the measurement of craniocervical flexor muscle performance.

Fluid shifts have no influence on ciprofloxacin pharmacokinetics in intensive care patients with intra-abdominal sepsis

This study aimed to investigate whether fluid shifts alter ciprofloxacin pharmacokinetics in critically ill patients over time. Patients >= 18 years, with normal renal function, requiring intensive care treatment and parenteral antibiotics were enrolled. Group A (22 patients) included patients with documented intra-abdominal infections. Group B (18 patients) included patients with severe sepsis from other causes. All patients received intravenous ciprofloxacin 400 mg every 8 h infused over 60 min. Eight timed blood specimens were taken on days 0, 2 and 7. Ciprofloxacin plasma concentrations were determined using high performance liquid chromatography. There were no significant differences between the pharmacokinetics of the two groups or over time. Ciprofloxacin pharmacokinetics in critically ill patients do not change over time, and intra-abdominal sepsis does not alter ciprofloxacin pharmacokinetic parameters to a greater degree than sepsis from other causes in critically ill patients. (c) 2005 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.