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PubMed2005

Abdominal muscle recruitment during a range of voluntary exercises.

Various exercises are used to retrain the abdominal muscles in the management of low back pain and other musculoskeletal disorders. However, few studies have directly investigated the activity of all the abdominal muscles or the recruitment of regions of the abdominal muscles during these manoeuvres. This study examined the activity of different regions of transversus abdominis (TrA), obliquus internus (OI) and externus abdominis (OE), and rectus abdominis (RA), and movement of the lumbar spine, pelvis and abdomen during inward movement of the lower abdominal wall, abdominal bracing, pelvic tilting, and inward movement of the lower and upper abdominal wall. Inward movement of the lower abdominal wall in supine produced greater activity of TrA compared to OI, OE and RA. During posterior pelvic tilting, middle OI was most active and with abdominal bracing, OE was predominantly recruited. Regions of TrA were recruited differentially and an inverse relationship between lumbopelvic motion and TrA electromyography (EMG) was found. This study indicates that inward movement of the lower abdominal wall in supine produces the most independent activity of TrA relative to the other abdominal muscles, recruitment varies between regions of TrA, and observation of abdominal and lumbopelvic motion may assist in evaluation of exercise performance.

Abdominal Muscles↗
PubMed2003

The effect of foot wedging on electromyographic activity in the erector spinae and gluteus medius muscles during walking.

The use of foot orthoses for treatment of low back pain (LBP) has received some attention in the literature, mainly from a clinical or theoretical perspective. It has been proposed that this treatment alleviates pain by altering muscle activity in the area of the low back but there is no direct evidence of such an effect. The objective of this study was to determine the effects of different types of foot wedging on the bilateral surface electromyographic activity of erector spinae (ErSp) (L3 level) and gluteus medius (GlMed) of 13 participants without LBP. Activity in ErSp had a significantly earlier onset during the gait cycle with bilateral heel lifts and bilateral lateral forefoot wedging. GlMed activity had a significantly later onset with bilateral heel lifts, and with an unilateral heel lift on the ipsilateral side (P<0.0125). No significant amplitude changes were demonstrated in either muscle for any of the forms of wedging tested. These results show that foot wedging can produce measurable changes in timing of muscle activity within the low back and pelvis during the gait cycle. Further investigation is required to determine whether this effect contributes to the alleviation of LBP.

Adult↗
PubMed2005

Assessment of efficacy and psychomotor performances of thiocolchicoside and tizanidine in patients with acute low back pain.

Objectives of this study were to assess efficacy and effects on psychomotor performances of thiocolchicoside (TCC) and tizanidine (TZ) compared to placebo. Patients complaining of acute low back pain (LBP) associated with muscle spasm were enrolled in this randomised, double-blind clinical trial, comparing the effects of oral TCC, TZ and placebo on psychomotor performances assessed by a visual analogue scale of tiredness, drowsiness, dizziness and alertness and by psychometric tests after 2 and 5-7 days of treatment. The efficacy assessments, both TCC and TZ, were more effective than placebo in improving pain at rest, hand-to-floor distance, Schober test and decreased paracetamol consumption. There were significant differences among the treatment groups in favour of TCC compared to TZ in visual analog scale-parameters. TZ-induced reduction of psychomotor performances of the patients was confirmed by psychometric tests, which showed significant differences among groups. This study showed that TCC is at least as effective as TZ in the treatment of acute LBP, while it appears devoid of any sedative effect in contrast to TZ.

Acute Disease↗
PubMed1996

Modifications of the paraspinous muscle flap: anatomy and clinical application.

Soft-tissue defects of the back, particularly involving the paravertebral tissues, are generally covered with myocutaneous, muscle, or fasciocutaneous flaps. The case of a 64-year-old man with a paravertebral malignant fibrous histiocytoma is reported. To ensure adequately radical margins, the ipsilateral trapezius and latissimus dorsi muscles as well as the costal periosteum and the spinous processes were resected between T9 and T12. The resulting defect was covered with a pedicled latissimus dorsi flap and an island flap of the paravertebral muscles. Prompted by this case, we studied the blood supply of the paravertebral muscles in 10 cadavers. The vasculature was visualized after flushing with colored latex and microsurgical dissection. Another 4 specimens were subjected to angiography and tomography. In the majority of cases (8 of 10), three perforators emerging from the intercostal arteries were identified. These were found to communicate in a longitudinal and vertical direction. Before piercing the fascia, they ramified in three layers matching the layers of the paravertebral muscles. Since the intercostal arteries were shown to communicate through anastomoses of adequate caliber, the paravertebral muscles appear to be useful candidates for proximally or distally pedicled transposition or island flaps.

Aged↗
PubMed1997

Spectral and temporal responses of trunk extensor electromyography to an isometric endurance test.

STUDY DESIGN: This study investigated the effect of trunk extensor muscle location on the spectral and temporal electromyographic activity of the muscles during a fatiguing isometric extension of the torso against gravity. OBJECTIVES: To determine the spectral responses of the trunk extensor muscles at more locations than have been studied previously, to determine if fatigue in the knee flexors limits this test, and to quantify the recruitment patterns of the trunk extensor muscles in a group of healthy subjects. SUMMARY OF BACKGROUND DATA: Isometric endurance tests appear to have more value than strength tests in predicting the occurrence of low back pain. Electromyographic activity of trunk extensor muscles during these tests may provide clues to the etiology of neuromuscular-based low back pain. Spectral electromyographic measures appear to be successful discriminators between low back pain patient and normal populations, although which muscles provide the best information is unclear. Likewise, the recruitment patterns of the trunk extensors during fatiguing isometric tasks is not well quantified. METHODS: Ten healthy men performed an isometric trunk endurance test. Surface electromyography was recorded from the erector spinae medially and laterally at vertebral levels of L1 and L3, medially at L5, and from the biceps femoris and gastrocnemius. Spectral parameters were calculated from the Fast Fourier Transform, and temporal parameters were calculated from the root mean square of the raw data. Linear regression was used to determine their responses as a function of time. RESULTS: There was a significant effect of vertebral level and medial-lateral location on the initial median frequency and linear slope of the median frequency regressions. No significant evidence of fatigue in the lower extremities was observed. For most subjects, the temporal response of the surface electromyography was parabolic (concave-down), peaking at 30-50% of the endurance time. CONCLUSION: Establishment of which muscle locations provide the best information and knowledge of the recruitment patterns are essential for the development of clinical diagnostic procedures and rehabilitation protocols.

Adult↗
PubMed1997

Assessment of nutritional status in CAPD patients: serum albumin is not a useful measure.

INTRODUCTION: In CAPD patients serum albumin is frequently used as an index of nutritional status, although it is recognized that hypoalbuminaemia may be caused by many factors. We have further examined the relationship between serum albumin and nutrition. METHODS: Nutritional status was assessed by biochemistry, anthropometry, mid-arm muscle circumference, muscle strength (hand grip and back), and lean body mass (from anthropometry, creatinine kinetics and bioimpedance) in a group of 76 stable CAPD patients. Correlations between biochemical and nutritional parameters were sought and data were compared between patient groups defined by serum albumin (> or = 37 vs < 37 g/l on two occasions 2 months apart) and separately according to subjective global assessment score (normal nutrition, A vs mild to moderate, B, and severe, C, malnutrition). RESULTS: In patients with a low SGA score, actual body weight, body mass index, mid-arm muscle circumference, lean body mass, subscapular skinfold thickness, hand grip strength (males and females) and iliac and triceps skinfold thicknesses and back strength (females only) were all significantly less than in patients with a normal SGA score. In contrast, none of these variables differed in either gender when patients were compared according to serum albumin. Serum albumin was correlated with serum creatinine (r = 0.45, P = 0.01), daily urine protein excretion (r = -0.42, P = 0.02) and uncorrected weekly creatinine clearance (r = -0.39) in females, but not with any index of body composition in either gender. CONCLUSION: Whilst SGA identified a patient group with significantly abnormal body mass, muscle mass and muscle strength, serum albumin did not. Serum albumin is not a useful marker of malnutrition in stable patients on CAPD.

Adolescent↗
PubMed2006

Treatment of chronic low back pain with successive injections of botulinum toxin a over 6 months: a prospective trial of 60 patients.

OBJECTIVES: The aim of this study was to evaluate the effects of two successive neurotoxin treatments for chronic low back pain using multiple pain rating scales in an open-label, prospective study. METHODS: Adult patients with chronic low back pain received multiple paraspinal muscle injections with a maximum dosing of 500 units of botulinum A toxin per session. Those with a beneficial clinical response received a second treatment at 4 months. Pain was assessed by visual analog scale (VAS), modified low back pain questionnaire (OLBPQ), and a clinical low back pain questionnaire (CLBPQ) at baseline, 3 weeks, 2 months, 4 months, and 6 months after the first treatment. RESULTS: Eighteen women and 42 men, ages 21 to 79 years (mean 46.6 years), with low back pain of a mean duration of 9.1 years were included. Significant improvement in back and radicular pain occurred at 3 weeks in 60% and at 2 months in 58% of the cohort. Beneficial clinical response to the first injection predicted response to reinjection in 94%. A significant minority of patients had a sustained beneficial effect from the first injection at 4 (16.6%) and 6 months (8.3%). Two patients had a transient flu-like reaction after the initial treatment. CONCLUSIONS: Botulinum toxin A improves refractory chronic low back pain with a low incidence of side effects. The beneficial clinical response is sustained with a second treatment.

Adult↗
PubMed2005

[Skeletal muscle histomorphometric study of rats in anestrus].

UNLABELLED: Castration, as well as the menopause, represents endocrine suppression that prevails the hypoestrogenism and their larger consequence on the skeletal muscle is to provoke sarcopenia. OBJECTIVE: To study the morphometric alteration of striated muscle of castrated female rats. METHODS: Twenty six female rats Wistar , distributed in two sub-groups, A and B, submitted initially to weigh-in place, vaginal cytology, ovariectomy, and biopsy of the muscle rectus femoris on the back paws, A group on right paw, and B on the left. Elapsed 20 days it was collected vaginal cytology to prove the anestrus status. After 70 days the animals went through weigh-in place, and new muscle biopsy, A group in left paw and B in right paw. The morphometric study was accomplished with the aids of a graduated lens, with reticules of 100 mm2, it was counted the myofibrils with six readings in the vertical and five in the horizontal in each sheet, being obtained a multiple number that applied on a specific formula to calculate the coefficient of muscular density. RESULTS: In A the muscular density varied from 60.0 to 52.33, (p<0.05%), with variation of 14.12%, and in B from 73.5 to 54.0, (p<0.05%), with variation of 26.53%. CONCLUSION: The castration provoked sarcopenia in the striated muscle and reduction of myofibrils number.

Anestrus↗
PubMed2006

Dehydration behavior and structural characterization of the GW275919X monohydrate.

GW275919X, a central muscle relaxant for the treatment of lower back pain, exists in a monohydrate. Knowledge of the solid state dehydration behavior and the crystal structure is essential for determining its relative physical stability. Thermal analysis and hot-stage powder X-ray diffraction were used to study the solid state phase transformation during the dehydration process. Crystal structure was determined by single crystal X-ray analysis. Molecular modeling with Cerius(2) software was used to visualize the hydrate crystal structure and to construct the molecular packing and hydrogen bond diagram. Morphology prediction was performed using the BFDH calculation. Crystallographic data: monoclinic, space group, P21/c, a (Angstrom)=14.3734, b (Angstrom)=5.0336, c (Angstrom)=15.4633 and beta=105.11 degrees. Water molecules in the hydrate crystal of GW275919X are involved in the hydrogen bonds and these hydrogen bonds contribute to the coherence of the crystal structure. The longest dimension of the predicted morphology is in the b-direction, which would correspond to the needle axis of the experimental crystals.

Benzimidazoles↗
PubMed2005

Epidemiology of injuries in English professional rugby union: part 2 training Injuries.

OBJECTIVES: To undertake a detailed epidemiological study of training injuries sustained by professional rugby union players in order to define their incidence, nature, severity, and causes. METHODS: A two season prospective design was used to study training injuries associated with 502 rugby union players at 11 English Premiership clubs. Team clinicians reported all training injuries on a weekly basis and provided details of the location, diagnosis, severity, and mechanism of each injury. Training exposures for individual players were recorded on a weekly basis. Loss of time from training and match play was used as the definition of an injury. RESULTS: The overall incidence of injury was 2.0 per 1000 player-hours, and each injury resulted on average in 24 days lost time. Recurrences, which accounted for 19% of injuries, were more severe (35 days) than new injuries (21 days). Twenty two per cent of all training occurred during the preseason but 34% of all injuries were sustained in this period. Hamstring, calf, hip flexor/quadriceps, and adductor muscle injuries were the most common for backs, whereas hamstring, lateral ankle ligament, and lumbar disc/nerve root injuries predominated for forwards. Lumbar disc/nerve root, shoulder dislocation/instability, and hamstring muscle injuries for forwards and hamstring muscle and anterior cruciate ligament injuries for backs caused the greatest number of days absence. Running was the predominant cause of injury for both forwards and backs, although the overall incidence and severity of injuries sustained during skills training were significantly greater than those sustained during conditioning training. CONCLUSIONS: On average, a club will have 5% of their players unavailable for selection as a consequence of training injuries.

Adult↗
PubMed1992

Interstitial exclusion of albumin in rat tissues measured by a continuous infusion method.

Steady-state 125I-labeled rat serum albumin (125I-labeled RSA) concentration in plasma was maintained by intravenous infusion of tracer for 72-168 h with an implanted osmotic pump. At the end of the infusion period, the rat was anesthetized and nephrectomized, and extracellular fluid was equilibrated with intravenous 51Cr-labeled EDTA for 4 h. Five minutes before final plasma and tissue sampling, 131I-labeled bovine serum albumin (131I-labeled BSA) was injected intravenously as a plasma volume marker. Samples of skin, muscle, tendon, and intestine were assayed for all three tracers. Apparent distribution volumes were calculated as tissue tracer content/plasma tracer concentration. Interstitial fluid volume (Vi) was calculated as V51Cr-EDTA-V131I-BSA. Steady-state extravascular distribution of 125I-labeled RSA as plasma equivalent volume (Va,p) was calculated as V125I-RSA-V131I-BSA. Steady-state interstitial fluid concentrations of 125I-labeled RSA in skin, muscles, and tendon were measured with nylon wicks implanted postmortem, and steady-state interstitial albumin distribution volumes were recalculated as wick-fluid equivalent volumes (Va,w). Relative albumin exclusion fraction (Ve/Vi) was calculated as 1-Va,w/Vi. For skin and muscle, steady-state 125I-labeled RSA tissue concentrations were reached at 72 h. Ve/Vi for albumin averaged 26% in hindlimb muscle, 41% in hindlimb skin, 30% in back skin, 39% in tail skin, and 54% in tail tendon. For muscle, Ve/Vi corresponds to expectation if all tissue collagen and hyaluronan is dispersed in the interstitium. However, for skin and tendon, albumin exclusion is considerably lower than expected on this basis, suggesting that much of their collagen is organized into dense bundles of fibers containing no fluid accessible to 51Cr-labeled EDTA or 125I-labeled RSA.

Animals↗
PubMed1993

The effects of quadriceps fatigue on the technique of lifting.

A biomechanical analysis was performed of lifting before and after fatiguing the quadriceps muscles. The hypothesis tested was that when the quadriceps muscles were fatigued the lifter would change lifting technique from more of a squat (leg) lift to more of a stoop (back) lift to decrease the demand on the quadriceps muscles. The hypothesis was broadly supported, and three variables changed significantly with fatigue: trunk angular velocity, which increased, and knee moment integral and hip angles, which both decreased. These changes are all consistent with a change from more of a squat toward a stoop technique. The fact that the technique of lifting changes with quadriceps muscle fatigue underlines the importance of the physiologic condition of these muscles and suggests that rehabilitation of low-back-injured workers should include the quadriceps muscles. The amount of work performed should be controlled to avoid the development of local muscle fatigue and subsequent changes in performance.

Adult↗
PubMed2000

Bilateral persistent complete sciatic artery.

A case with persistent sciatic artery (PSA) was found in a cadaver of a 65-year-old female during a medical gross anatomy course. The artery was bilateral and complete and provided the major blood supply to both lower extremities. The vessel arose from the internal iliac artery that was extremely large bilaterally. The sciatic artery passed out of the pelvis through the infrapiriform foramen and descended posterior to the sciatic nerve through the gluteal region. The sciatic nerve was considerably flattened out under the artery. Large articular branches arose from the part of the artery at the buttock just below the piriform muscle. The artery descended along the back of the thigh and was crossed obliquely posteriorly by the long head of the biceps femoris muscle. The sciatic artery continued as the popliteal artery located very superficially in the popliteal fossa. A companion vein, i.e., the sciatic vein, accompanied each artery. The right sciatic vein entered the pelvis posteriorly through the infrapiriform foramen, whereas the left perforated the quadriceps muscle from behind and joined the femoral vein anteriorly. There was a gracile superficial femoral artery bilaterally. The deep femoral arteries of both lower limbs were hypoplastic with slender circumflex branches. There were no macroscopic connections between the sciatic and the deep or superficial femoral arteries on either side. This anomaly should be kept in mind in the evaluation of patients with sciatic or buttock pain or palpable "pulsating" buttock mass. Persistent sciatic artery also could be a potential hazard during orthopedic manipulations, hip joint surgery, and renal transplant surgery.

Aged↗
PubMed2007

Rehabilitative ultrasound measurement of select trunk muscle activation during induced pain.

Rehabilitative ultrasound imaging (RUSI) is considered a valid method to measure muscle activation in key spinal muscles in asymptomatic subjects. Research measuring muscle activation with RUSI in painful subjects is limited. The aim of this study was to determine if changes in muscle activation from experimentally induced pain can be measured by RUSI. Six male subjects performed tasks known to activate the transverse abdominis (TrA) and lumbar multifidus (LM) while RUSI measurements of muscle thickness were obtained during control and hypertonic saline conditions. The abdominal draw-in maneuver was used to volitionally activate the TrA and a series of upper extremity lifting tasks were used to automatically activate the LM. Pain was induced by injecting 5% hypertonic saline into the longissimus muscle adjacent to the LM at the L4 level. The percent change in muscle thickness from rest to contraction represented muscle activation. Activation was significantly less (p<0.01) during the painful condition on 4 of the 5 tasks performed for the LM and on the task performed for the TrA. These results indicate that RUSI can be used to measure pain-related changes in deep trunk muscle activation. Future research should include a larger sample size and women.

Abdominal Muscles↗
PubMed1981

Pathway selection by chick lumbosacral motoneurons during normal development.

Pathways taken by motoneuron axons from the lumbosacral lateral motor column to individual hindlimb muscles have been characterized throughout the normal period of outgrowth and the establishment of specific functional connections in the chick embryo. Axon pathways from individual cord segments were identified after injections of horseradish peroxidase (HRP) directly into the cord. Labelled motoneuron axons were then traced through the plexus and major nerve trunks to termination sites within the limb. At stages 23-24 labelled axons within spinal nerves have just reached the base of the limb and have begun to converge and form the crural and the ischiadic plexus. Even at this early stage, before periods of muscle cleavage, motoneuron cell death and muscle nerve formation, axons show no evidence of widespread random distribution within the limb. Rather, they generally maintain their anterior-posterior position as far as the base of the limb. At stages 27-30, although axons to individual muscles were found to course in discrete tracts within the plexus and nerve trunks they also changed their topographical position with respect to other axons. Axon pathways to single muscles were characterized by tracing retrogradely labelled axons back to the cord after injections of HRP into specific muscle nerves. Axons destined for a single muscle are intermingled with other axons in the spinal nerves and proximal plexus but by the distal plexus have converged to form a discrete tract which then diverges as an individual muscle nerve at more distal levels. These observations exclude models for the establishment of specific connections in which there is widespread testing of the environment with removal of projection errors by cell death and/or axon retraction. They also exclude models that require axons to maintain their topographical position with respect to each other throughout their course.

Animals↗
PubMed1987

Recruitment of internal oblique and transversus abdominis muscles during the eccentric phase of the curl-up exercise.

The purpose of this study was to analyze the results of a training method to increase voluntary recruitment of internal oblique and transversus abdominis muscles. Forty volunteers were assigned to either a Control or an Experimental Group. Training consisted of multisensory (auditory, tactile, visual, and kinesthetic) cuing focused on the lower abdominal muscles during the slow curl-back (eccentric) phase of curl-up exercises with the subjects' feet unsupported. We recorded integrated electromyographic (IEMG) values using surface electrodes from internal oblique and transversus abdominis muscles during pretest and posttest exercises. Using an analysis of covariance, posttest IEMG values of the Experimental Group were significantly higher (p less than .001) than the Control Group. Our results reveal that multisensory cuing with the feet unsupported during the curl-back is an effective method of increasing combined recruitment of internal oblique and transversus abdominis muscles. Motor skills developed by this technique are discussed in relation to optimal trunk function and rehabilitation.

Abdominal Muscles↗
PubMed1997

Bimedial rectus recession using the anchored hang-back technique.

Hang-back recession of a rectus muscle offers several advantages over conventional techniques: a reduced risk of scleral perforation, easy intraoperative adjustment, and a convenient site for suturing to the sclera. There are also disadvantages: the muscle tends to collapse, thereby increasing the effective recession and making the result less predictable. In addition, the insertion cannot accurately be displaced upward or downward, as may be required to correct A- and V-patterns, or vertical deviations. The authors describe a modified technique, an anchored hang-back recession, and discuss the results in 60 consecutive cases of bimedial rectus recession.

Amblyopia↗