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PubMed1983

Ultrasonic tissue characterisation of skeletal muscle.

Ultrasound techniques have been used for the non-invasive, quantitative characterisation of muscle tissue in normal subjects and volunteer patients. Radio frequency (RF) echoes from a volume of tissue have been digitised and analysed using computer techniques. Attention has been given to the correct positioning and orientation of the transducer during examination due to the importance of the angle dependence of the interaction of ultrasound with muscle fasciculi. Several different muscles in the leg, arm and back of normal subjects have been examined, whereas patient studies have concentrated on the vastus intermedius. Ultrasonic data from patients with muscular dystrophy have been correlated with measurements of muscle tissue density obtained using X-ray computerised tomography (X-ray CT). The technique shows that ultrasound can be used to differentiate between normal and diseased muscle quantitatively. Results indicate that pathological change can be detected and monitored earlier with ultrasound than with X-ray CT. These quantitative methods are now in use as a guide to the staging and monitoring of pathological change in muscle.

Fascia↗
PubMed2001

Neuromuscular Evaluation of Trunk-Training Exercises.

OBJECTIVE: To evaluate the neuromuscular activation profiles of trunk muscles in commonly used gymnastic strength exercises with a polymyographic set-up and to describe the training effects of each exercise. DESIGN AND SETTING: Subjects performed 9 repetitions of each of 12 gymnastic exercises. Variations of 5 trunk flexions, 5 extensions, and 2 lateral-flexion movements were performed under standardized test conditions. SUBJECTS: Ten healthy subjects (men and women) who were familiar with the exercises participated in the study. MEASUREMENTS: We recorded surface electromyograms (EMGs) from the rectus abdominis, external oblique, rectus femoris, middle trapezius, erector spinae at T12 and L3, gluteus maximus, and semitendinosus and semimembranosus muscles. Recording of each repetition cycle was triggered by a flexible electronic goniometer attached to the trunk. The raw EMG signals were rectified, smoothed, amplitude normalized to maximal voluntary contraction (MVC), and averaged for the last 8 repetitions. RESULTS: Pure spine-flexion exercises, such as a curl-up, produced sufficient and isolated activation (greater than 50% MVC) of the abdominal muscles. When flexion of the spine was combined with hip flexion (sit-up), the peak activation was increased. Lateral-flexion tasks targeted primarily the external oblique muscle, which demonstrated high activity in side-lying flexion tasks. Back- and hip-extension exercises, such as bridging and diagonal hip and shoulder extension, produced only moderate mean activities (less than 35% MVC) in the trunk-extensor muscles. Trunk-extension exercises with combined hip extension increased the EMG activity to 50% MVC but only at the end of the extension. CONCLUSIONS: Individual responses to each exercise varied markedly, which complicated the classification of exercise effects. However, within the limitations of the study, we found that the chosen abdominal exercises provided an effective training stimulus for the trunk-flexor muscles, whereas in the back- and hip-extension exercises, the neuromuscular activation tended to be too low or unspecific to qualify as muscle-specific training.

Journal Article↗
PubMed2002

Diazepam as an adjuvant analgesic to morphine for pain due to skeletal muscle spasm.

Side effects of morphine are common when it is given in titrated doses to control severe pain in advanced cancer. We describe a case of severe back pain resistant to parenteral morphine accompanied by muscle spasm, in which the addition of diazepam both had an opioid-sparing effect and provided superior symptomatic relief. Diazepam appears to have a specific role as an adjuvant analgesic for pain due to skeletal muscle spasm associated with painful vertebral metastases.

Back Pain↗
PubMed2005

Co-contraction recruitment and spinal load during isometric trunk flexion and extension.

BACKGROUND: Pushing and pulling tasks account for 20% of occupational low-back injury claims. Primary torso muscle groups recruited during pushing tasks include rectus abdominis and the external obliques. However, analyses suggest that antagonistic co-contraction of the paraspinal muscles is necessary to stabilize the spine during flexion exertions. The study quantified co-contraction and spinal load differences during isometric flexion and extension exertions. The goal was to provide insight into the mechanisms requiring greater co-contraction during trunk flexion exertions compared to extension exertions. METHODS: Electromyographic (EMG) signals were recorded from the trunk muscles of healthy volunteers during isometric trunk flexion and extension exertions. A biomechanical model was implemented to estimate total muscle force from the measured EMG and trunk moment data. A similar model estimated the muscle forces necessary to achieve equilibrium while minimizing the sum of squared muscle forces. The difference in these forces represented co-contraction. Spinal load attributed to co-contraction was computed. RESULTS: Average co-contraction during flexion exertions was approximately twice the value of co-contraction during extension, i.e. 28% and 13% of total muscle forces respectively. Co-contraction accounted for up to 47% of the total spinal load during flexion exertions. Consequently, spinal compression during the flexion tasks was nearly 50% greater than during extension exertions despite similar levels of trunk moment. INTERPRETATION: Co-contraction must be considered when evaluating spinal load during pushing exertions. Results underscore the need to consider neuromuscular control of spinal stability when evaluating the biomechanical risks.

Adult↗
PubMed2005

Spine loading as a function of lift frequency, exposure duration, and work experience.

BACKGROUND: Physiological and psychophysical studies of the effects of lifting frequency have focused on whole-body measurements of fatigue or subjective acceptance of the task and have not considered how spine loads may change as a function of lift frequency or lift time exposure. Our understanding of biomechanical spine loading has been extrapolated from short lifting bouts to the entire work day and may have led us to incorrect assumptions. The objective of this project was to document how spine loading changes as a function of experience, lift frequency, and lift duration while repetitively lifting over the course of an 8-h workday. METHODS: Twelve novice and twelve experienced manual materials handlers performed repetitive, asymmetric lifts at different load and lift frequency levels throughout an 8-h exposure period. Compression, anterior-posterior shear, and lateral shear were evaluated over the lifting period using an EMG-assisted biomechanical model. RESULTS: Spinal loads increased after the first 2 h of lifting exposure regardless of the lift frequency. Loading was also greater for the inexperienced subjects compared to experienced lifters. The greatest spine loads occurred at those lift frequencies and weights to which the workers were unaccustomed. INTERPRETATION: Increases in spine loading were tracked back to the changes in muscle recruitment patterns that typically involved increased muscle coactivation. The results emphasize the importance of previous motor programming in defining spine loads during repetitive lifting. These results indicate a very different influence of frequency and lift time exposure compared to physiologic and psychophysical assessments. This study has shown that it is not sufficient to extrapolate from short lift periods to extended exposure periods if the biomechanical loading implications of the task are of interest.

Adult↗
PubMed2002

Efferent tube suspension as a continent diversion mechanism: a preliminary report of a clinical study.

PURPOSE: We constructed a reliable continent tube that is surgically simple. MATERIALS AND METHODS: In 12 patients with malignant bladder tumor we performed radical cystectomy with isolation of a 50 cm. ileal loop with pedicle. The proximal segment (8 to 10 cm.) was tapered over a 16Fr catheter as an efferent tube, the remaining segment was detubularized to create a W-shape pouch and the tapered ileum was fixed to the back surface of the rectus muscle with 2 polyester tapers 1 cm. wide with a suspension tension of 500 g. The external orifice of the tapered ileum was anastomosed to the umbilicus. In 2 patients with neuropathic bladder a 15 cm. ileal loop with pedicle was isolated, the proximal segment (8 cm.) was tapered as an efferent tube with 500 g. suspension tension, and the remaining segment was detubularized and anastomosed to the bladder. RESULTS: The patients were followed for 6 to 17 months (mean 11.4) and were completely continent day and night. The stoma was easily catheterized with a 16Fr catheter in all cases. Urodynamic study of the efferent tubes revealed maximum pressure of 84 to 159 cm. water (mean 114). Retrograde radiography of the efferent tubes demonstrated perfect canalization without stenosis. CONCLUSIONS: This study suggests that the continent mechanism of the tapered ileum can be greatly enhanced by a suspension technique. This maneuver also provides easy catheterization and surgical simplicity.

Adolescent↗
PubMed1992

Acute renal failure following binge drinking and nonsteroidal antiinflammatory drugs.

Two college students who developed reversible acute deterioration in renal function following binge drinking of beer and the use of nonsteroidal antiinflammatory drugs (NSAIDs) are reported. Both patients presented with back and flank pain with muscle tenderness, but showed no evidence of overt rhabdomyolysis. The first case had marked renal failure, with a peak serum creatinine reaching 575 mumol/L (6.5 mg/dL), and acute tubular necrosis was documented by renal biopsy. The second case had only modest elevation in serum creatinine, and renal function rapidly improved on rehydration. The contribution of the potential muscle damage associated with alcohol ingestion to the changes in renal function in these two cases is not clear. However, the major mechanism for the acute renal failure was thought to be related to inhibition of renal prostaglandin synthesis in the face of compromised renal hemodynamics secondary to alcohol-induced volume depletion.

Acute Kidney Injury↗
PubMed1996

Occult spinal dysraphism--the common combination of lesions and the clinical manifestations in 50 patients.

Fifty patients (26 males, 24 females) aged from birth to 51 years with occult spinal dysraphism were identified. All had Magnetic Resonance (MR) scans carried out. The MR scans were examined to determine the vertebral level of the conus and to see if one or more of the following were present; lipoma, syrinx, dermoid, diastematomyelia, and meningocele. In 43 patients the conus lay below the level of L3, 23 had a lipoma, 23 a meningocele, 20 an open central canal in the spinal cord or a syrinx, 15 a diastematomyelia and 4 a dermoid. The commonest combination of lesions was a long cord, a syrinx or an open central canal in the spinal cord and a lipoma. The diastematomyelias were always associated with a long cord and had the highest incidence of vertebral body anomalies (60%). The most frequent recorded signs were deformities of the feet, short legs, wasting of the calf muscles, weakness of the legs, back pain and bladder dysfunction. Combinations of these occurred with all of the lesions although some had none. Whilst deterioration was seen in about half of the patients, acute deterioration was uncommon and was associated most frequently with a dermoid or an expanded syrinx.

Abnormalities, Multiple↗
PubMed2003

Valgus intertrochanteric osteotomy for malunion and nonunion of trochanteric fractures.

OBJECTIVE: To evaluate the results of valgus intertrochanteric osteotomy for varus nonunion and malunion of trochanteric fractures. SETTING: University hospital. DESIGN: Retrospective clinical study. PATIENTS: Fifteen patients (age range 29-84 years) with varus malunion (11 cases) or varus nonunion (4 cases). Indication for surgery was nonunion or varus malunion with limb shortening greater than 2 cm associated with limp, abductor muscle insufficiency, hip pain, and back pain. INTERVENTION: The patients were treated by a valgus intertrochanteric osteotomy fixed with a 120 degrees double-angled blade plate. RESULTS: Average follow-up was 5.5 years (range 2-10 years). Fourteen patients healed without complications: 12 patients within 4 months; 2 delayed unions within 6 months. One patient required revision surgery for a loss of fixation due to a fall 6 weeks after surgery. This osteotomy also healed. Average lengthening achieved by osteotomy was 2 cm (range 1-5 cm). In all patients, the resulting range of flexion in the hip joint was greater than 90 degrees, Harris hip score before surgery was 73 points (range 61-83), and after surgery 92 points (range 76-98). Osteoarthritis or avascular necrosis of the femoral head did not develop in any of the cases. CONCLUSION: Valgus intertrochanteric osteotomy is an effective procedure that reliably restores hip function in trochanteric malunion or nonunion.

Adult↗
PubMed1997

Anterior decompression of foraminal stenosis below a lumbosacral transitional vertebra. A case report.

STUDY DESIGN: A case of unilateral far-out foraminal entrapment of the L5 spinal nerve below a transitional vertebra is presented with a review of the literature. OBJECTIVES: To describe management of a rare far-out foraminal stenosis below a transitional vertebra and to evaluate the surgical procedure and results. SUMMARY OF BACKGROUND DATA: Far-out foraminal stenosis with radiculopathy caused by bony spur formation secondary to anomalous articulation between the transverse process and the sacral ala is rarely reported. Decompression at this point traditionally has been performed through a posterior approach, similar to that performed for the far-out syndrome. There are no previous reports describing anterior decompression through an extraperitoneal approach. METHODS: The diagnosis was confirmed by computed tomography, magnetic resonance imaging, and selective radiculography. Anterior decompression was performed by resecting the bony spur using a wide muscle-splitting extraperitoneal approach. RESULTS: Anterior decompression was performed with minimal intervention to the spine and the trunk muscles. Good relief of low back pain and sciatica was obtained. CONCLUSIONS: Selective radiculography was the method of examination with the optimal diagnostic value for far-out foraminal stenosis. An anterior approach to the decompression of far-out foraminal stenosis below a lumbosacral transitional vertebra is a relatively simple and effective method.

Adult↗
PubMed1989

Gating of retinal transmission by afferent eye position and movement signals.

Vision in most vertebrates is an active process that requires the brain to combine retinal signals with information about eye movement. Eye movement information may feed forward from the motor control areas of the brain or feed back from the extrinsic eye muscles. Feedback signals elicited by passive eye movement selectively gate retinal outflow at the first relay, the dorsal lateral geniculate nucleus. The gating predominantly facilitates retinogeniculate transmission immediately after eye movement and inhibits transmission when a new steady-state eye position is achieved. These two gating effects are distributed in a complementary fashion across the dorsal lateral geniculate nucleus such that the spatiotemporal activity profile could contribute to object detection and localization.

Action Potentials↗
PubMed2002

Study of efferent tube suspension as a continent diversion mechanism. an experimental study in dogs.

PURPOSE: To construct a reliable continent tube, which is easy to catheterize and surgically simple. MATERIALS AND METHODS: 8 adult female mongrel dogs underwent a procedure in which an ileal segment was tapered as an efferent tube. The tapered ileum was fixed to the back surface of the rectus muscle with a polyester taper 1.5 cm in width and a suspension tension of 400 g. The internal orifice of the tapered ileum was anastomosed to the bladder and the external orifice of the tapered ileum was brought out to the abdominal skin. Urodynamic and radiological studies were carried out postoperatively in all dogs. RESULTS: All stomas in dogs could be easily catheterized with a 14-french catheter. Urodynamic study of the efferent tubes showed that the maximum closure pressure ranged from 117 to 157 (mean 136.75) cm water. Retrograde radiogram of the efferent tubes showed perfect canalization without stenosis. CONCLUSION: This study suggests that the continent mechanism of the tapered ileum can be greatly enhanced by a suspension technique.

Animals↗
PubMed2005

Score-celebration injuries among soccer players: a report of 9 cases.

BACKGROUND: Professional and amateur soccer players often perform dramatic on-field feats of celebration after scoring a goal. Injuries may occur during these activities. PURPOSE: With the aim of preventing such "score-celebration injuries" in the future, the authors examine these events in professional soccer players and discuss potential avenues for prevention. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Over the course of 2 seasons (1996-1998), 152 soccer players were evaluated at an orthopaedic clinic for injuries incurred during matches. Nine players (6%) had injured themselves while celebrating after scoring goals in a match. The type of celebration, injury type, treatment, and mean duration of recovery were noted. RESULTS: Seven of the 9 patients were male professional soccer players with ages ranging between 17 and 29 years (mean age, 24 years). The injuries occurred when the playing ground was natural turf in 8 cases; most injuries occurred in the second half of the game. The types of celebration maneuvers were sliding (prone or supine) and sliding while kneeling in 5 cases, piling up on jubilant teammates in 3 cases, and being tackled while racing away in 1 case. Injuries included ankle, clavicle, and rib fractures; medial collateral ligament sprain; low back strain; hamstring and adductor muscle strain; quadriceps muscle sprain; and coccyx contusion. The mean duration for recovery was 6.2 weeks. Rival team players were usually not responsible for such trauma. CONCLUSION: Exaggerated celebrations after making a goal, such as sliding, piling up, and tackling a teammate when racing away, can result in serious injury. In addition to general measures for preventing soccer injuries, coaches and team physicians should teach self-control and behavior modification to minimize the risk of such injuries. More restrictive rules, which penalize such behavior, may assist in the prevention of score-celebration injuries.

Adolescent↗
PubMed1989

Use of Telazol to immobilize female northern sea lions (Eumetopias jubatus) in Alaska.

Twenty-nine female northern sea lions (Eumetopias jubatus) were immobilized using Telazol in dosages ranging from 1.8 to 8.1 mg/kg. Best results were achieved with Telazol dosages ranging between 1.8 and 2.5 mg/kg which resulted in smooth induction and recovery. Optimal injection location was in the muscle mass of the lower back and hip. Dosages greater than 3.5 mg/kg resulted in a tendency toward hypothermia. Six mortalities occurred which were partially caused by the location of drug injection and perhaps the high dosage.

Alaska↗
PubMed1999

[Somite patterning and segregation of different somite lineages].

The somite is a transient embryonic mesodermal structure, found only in vertebrates. In amniotes, somites give rise to the dermis of the back, to the striated skeletal muscles of the trunk and limbs and to the vertebral column and ribs. Segregation of these different lineages is linked to the establishment of two somitic polarity axes, a dorso-ventral one and a medio-lateral one. While the establishment of the former relies essentially on extrinsic cues, that of the latter obeys to both intrinsic and extrinsic mechanisms. Concerning the environmental cues regulating the establishment of both axes, somitic regionalisation results from antagonistic or combinatorial influences mediated by diffusible factors, such as Sonic Hedgehog, Wnt and Bmp-4, that act in gradients.

Animals↗
PubMed2001

Enhanced continent mechanism of tapered ileum by extramural support from the pouch and abdominal walls: a preliminary report of a clinical study.

PURPOSE: We constructed a reliable continent tube that is easy to catheterize and surgically simple. MATERIALS AND METHODS: Eight patients with bladder cancer underwent a procedure in which ileal segment was tapered as an efferent tube, of which a part was placed between the back surface of the rectus muscle and the ileal pouch wall. The internal orifice of the tapered ileum was anastomosed to the ileal pouch and its external orifice was anastomosed to the umbilicus. Urodynamic and radiological studies were done postoperatively in 7 cases. RESULTS: The stoma was easily catheterized with a 16Fr catheter in all cases. One patient died of heart disease 55 days postoperatively, while 6 of the remaining 7 were completely continent day and night. Urodynamic study of the efferent tubes showed that maximum close pressure with the pouch full was significantly higher than with the pouch empty (p <0.001). Retrograde radiography of the efferent tubes demonstrated perfect canalization without stenosis. CONCLUSIONS: This study indicates that the continent mechanism of tapered ileum may be greatly enhanced by fixing it between the abdominal and pouch walls. This maneuver also provides easy catheterization and surgical simplicity.

Abdominal Muscles↗