[Ultrastructure of the motor ends of the beta-axon on intra- and extrafusal muscle fibers in rat quadriceps muscle].
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Animals↗
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Results for “Quadriceps Muscle”
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Swelling of the knee joint: effects of exercise on quadriceps muscle strength.
OBJECTIVE: To investigate the effects of excessive fluid in the knee joint on the performance of the quadriceps muscles and to determine whether quadriceps muscle performance can be altered by exercising the swollen joint. DESIGN AND SETTING: A before-after trial design was used, and the procedures were performed in a laboratory setting. SUBJECTS: A random sample of 27 adult men with no musculoskeletal problems was divided into intervention and control groups. INTERVENTION: First, in all groups, torque generated by the quadriceps muscle was examined by isokinetic muscle testing undertaken at a joint angular velocity of 120 degrees/sec over a range of motion from 5 degrees to 80 degrees flexion. After this initial test, in group 1, 60mL saline and dextrose was injected into the knee joint and subjects repeated the maximal effort procedure. Subjects then performed submaximal exercise for 3 to 4 minutes, after which maximal effort testing was undertaken again. In group 2, subjects received no injection of fluid, undertook 2 maximum effort tests, then performed submaximal exercise for 3 to 4 minutes, after which maximum effort testing was undertaken again. In group 3 (control group), subjects undertook three maximum effort tests over a time period similar to that for the other groups. MAIN OUTCOME MEASURE: Quadriceps muscle torque generated at 60 degrees from full knee extension. RESULTS: Torque decreased (p < .05) 30% immediately after the injection of fluid. However, torque returned to preinjection levels after submaximal exercise (p > .05). These findings were related to joint capsule compliance and fluid movement. No significant changes (p > .05) in torque were observed for the other two groups. CONCLUSION: Submaximal exercise of swollen knee joints can decrease artificially induced quadriceps muscle inhibition. These findings may have implications for patients with perennial effusions who at times undertake gait activities.
Adult↗
Quadriceps muscle function after high tibial osteotomy for osteoarthritis of the knee.
In patients with osteoarthritis of the knees, quadriceps muscle dysfunction is an early and common clinical feature and an important determinant of disability. In the current study, changes in quadriceps muscle strength and voluntary quadriceps muscle activation after high tibial osteotomies for primary osteoarthritis of the knee in 19 patients were investigated. Quadriceps muscle function was assessed during different degrees of isometric maximum voluntary contraction using a specially built chair. One year after surgery all patients had reexamination of their surgically treated and contralateral knees. Voluntary activation and maximum voluntary contraction values of the followup assessment were significantly lower in the surgically treated knees compared with the preoperative assessment. In the contralateral knees, there were no differences between preoperative and followup measurements. High tibial osteotomy is an extraarticular operative therapeutic approach to treatment of osteoarthritis of the knee that does not lead to improvement of quadriceps muscle function. Because there is evidence that quadriceps sensorimotor dysfunction is important not only for the disability in osteoarthritis of the knee, but also for progression of the disease, knee function may be worsened by high tibial osteotomy in some patients.
Aged↗
The spectrum of disease in weakness and wasting of the quadriceps muscles. Case reports.
Three patients who presented with weakness and wasting of the quadriceps muscles ('quadriceps myopathy'), are reported. In each, electrophysiological and biopsy studies revealed completely different pathological processes, including motor unit disease, polymyositis and muscular dystrophy. Double biopsies performed in 2 of the patients showed the disease process to involve upper as well as lower limbs. The diffuse and heterogeneous nature of this form of neuromuscular disease is confirmed.
Aged↗
[Physiology & pathomechanisms of the knee without extensor muscles; case report of sarcoma of quadriceps muscle].
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Humans↗
The splenius capitis muscle of the rat, architecture and histochemistry, afferent and efferent innervation as compared with that of the quadriceps muscle.
The splenius muscle of the rat was investigated with regard to its structure and innervation. The latter was compared with that of the quadriceps muscle. The results can be summarized as follows: The splenius muscles of both sides form a bipennate muscle plate connecting the occipital bone with the spinous process of the second thoracic vertebra. The lateral parts of both muscles are attached directly to this prominent bony process, whereas the medial parts end in a median raphe which forms a tendinous cranial extension of the second thoracic vertebra. This tendinous extension, showing no connection to the cervical vertebrae, serves also for the attachment of acromio-trapezius muscle fibers. The lateral part of the splenius muscle is divided into two parts by a tendinous intersection. The splenius muscle consists mainly of fast twitch fibers: 55% were characterized as IIB and 40% as IIA fibers by histochemical demonstration of myosin ATPase-activity. A high content of muscle spindles--57 spindles per gram of muscle tissue--was found. Comparing several aspects of the innervation of the splenius to that of the quadriceps muscle, the following results could be obtained: The ratio of motor end plate size to muscle fiber volume is significantly higher in the splenius than in the quadriceps muscle. As demonstrated by transganglionary HRP-transport, the main part of labeled splenius afferents to the spinal cord terminates in the central cervical nucleus. Quadriceps afferents, entering the lower thoracic and upper lumbar segments, mainly end in the area of Clarke's column. Several labeled fibers descend to the sixth lumbar and first sacral segments, where they terminate in the area of Stilling's nucleus. A group of primary afferents from both muscles--most probably III- and IV-afferents--projects to the dorsal laminae of the dorsal horn; terminals from the splenius are accumulated in the lateral parts of these laminae, whereas those of the quadriceps are more concentrated in the medial areas. Within the brain stem, most afferents from the splenius terminate in the external cuneate nucleus. Most of the quadriceps afferents course to the gracile nucleus. Terminals from both muscle nerves were found in the area of the spinal vestibular nucleus. In conclusion, the most conspicuous results were: 1) Besides the segmental projection to the dorsal horn there is an almost exclusive projection of splenius primary afferents to relay nuclei to the cerebellum. 2) The relatively high ratio: end plate size/muscle fiber volume, which is characteristic of finely adjusting muscles.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
Inhibition of the quadriceps muscles in elite male volleyball players.
Inhibition of the quadriceps muscles was assessed in 13 elite male volleyball players using the interpolated twitch technique. This technique involves applying an electrical stimulus to the voluntarily contracted quadriceps muscles to estimate the number of motor units not fully activated during the contraction. Knee extensor moments and muscle inhibition were measured during isometric contractions at knee angles of 30 degrees and 60 degrees from full extension. A medical history of knee joint injury and pain experienced in the knee during testing were assessed. Previous knee joint injury did not affect the knee extensor moments, but produced a difference in muscle inhibition: muscle inhibition in legs with previous injuries was significantly lower than muscle inhibition in legs with no previous injury. Moderate pain in the knee during testing did not affect muscle inhibition, but was associated with reduced knee extensor moments. We consider that the loss in knee extensor moments associated with pain might be caused by atrophy of the quadriceps muscles as a consequence of the disrupted training routine. The lower muscle inhibition in volleyball players with previous injury suggested that the intense rehabilitation programme that these athletes undergo after knee injury improves muscle activation. As a result, athletes with previous knee joint injuries were able to produce the same knee extensor moments as athletes with no previous injury, probably because of their ability to recruit the available motor units more completely. This recruitment may compensate for the possible loss in muscle mass encountered during the period of injury and detraining.
Adult↗
Electromyographic predictors of residual quadriceps muscle weakness after anterior cruciate ligament reconstruction.
BACKGROUND: Despite the high prevalence of residual quadriceps muscle weakness after anterior cruciate ligament reconstruction, specific predictive factors have not been identified. HYPOTHESIS: Electromyographic analysis is a better predictor of residual muscle weakness than is preoperative strength. STUDY DESIGN: Prospective cohort study. METHODS: The quadriceps muscle strength of 37 patients (25 men, 12 women) was measured before reconstruction and 5 weeks and 6 months after surgery. Quadriceps surface electromyographic signals were recorded during all of the strength tests. Integrated electromyographic analysis and median frequency measurements were computed as deficits on the involved side. Patients also performed a single-legged hop test at the 6-month follow-up examination. RESULTS: The patients had significantly lower strength, integrated electromyographic analysis, and median frequency measurements on the involved side at all three time intervals. The best predictor of the quadriceps muscle strength deficit at 6 months was the combination of the preoperative median frequency deficit and the 5-week postoperative strength deficit. The best predictor of the hop test deficit at 6 months was the combination of preoperative deficits in integrated electromyographic analysis and median frequency. CONCLUSION: Preoperative electromyographic indices of quadriceps muscle function and early postoperative strength were predictive of residual weakness and impaired function 6 months after reconstruction.
Adult↗
Associations between walking time, quadriceps muscle strength and cardiovascular capacity in patients with rheumatoid arthritis and ankylosing spondylitis.
The aim of this study was to examine whether there are any associations between walking time, quadriceps muscle strength and cardiovascular capacity in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Thirty-one patients with RA and 26 patients with AS belonging to Steinbrocker's functional class I-II were examined. Cardiovascular capacity was calculated from the expired air during a bicycle test and quadriceps muscle strength by the peak torque from an isokinetic dynamometer test. Walking time was the time it took to walk a distance of 160 m on a flat floor and to climb up and down a staircase. In patients with RA, flat floor walking and stair climbing times correlated inversely with quadriceps muscle strength and cardiovascular capacity. Similar results were seen in patients with AS, although the association between cardiovascular capacity and stair-climbing time was not statistically significant. Multiple regression analysis was performed for all patients with quadriceps muscle strength and cardiovascular capacity applied as independent variables in two separate models. Cardiovascular capacity explained 32% and quadriceps muscle strength 21% of the variance in flat floor walking time. Quadriceps muscle strength, together with diagnosis and age, explained 38% of the variance in stair-climbing time, and cardiovascular capacity together with age and pain explained 36% of the variance. In conclusion, in spite of cardiovascular capacity and quadriceps muscle strength being associated with walking times, the findings suggest that they play only a modest role in explaining rapid walking on flat floor and in stairs.
Activities of Daily Living↗
[Muscle strength and muscle blood flow of the quadriceps muscle].
This study was conducted to measure muscle blood flow changes during increased muscle strength in order to determine what characteristic parameters of muscle strength were most closely correlated with increased muscle blood flow. The muscle blood flow and muscle strength in the quadriceps femoris were measured simultaneously during isokinetic extension of the knee joints in two groups--one with knee-joint-disease and the other of healthy volunteers. Muscle blood flow was measured by the heated thermocouple technique, while parameters of muscle strength were evaluated utilizing curves calculated by a Cybex II. The test results showed a positive correlation between parameters of muscle strength (peak torque, total work and average power) and peak blood flow. However, both the muscle strength and the muscle blood flow values were less in the group with knee joint disease than in the group of healthy volunteers. In both groups, the muscle blood flow was greatest when the knee was extended at an increased angular velocity. Although the muscle blood flow was greatest at this time, only the parameter of average power increased while the parameter of peak torque and total work decreased. As a result, the average power was correlated most closely with the increased muscle blood flow. In patients with a knee joint disease, the increase in the muscle blood flow was much higher than expected despite the fact that there was little increase in average power during knee movement at an increased angular velocity. It appeared that the pathological condition in these patients' quadriceps femoris required increased blood flow despite an inability of the muscle to perform increased muscle work.
Adolescent↗
Dynamic strength of the quadriceps muscle and sports activity.
The study objectives were to examine the dynamic strength of the quadriceps muscle in athletes, and investigate its association with participation in sport. The study comprised 168 active competitive non-pregnant athletes, aged 14-24 years. The dynamic strength of their quadriceps muscle was measured, and they answered a questionnaire about sports activity and occupation. The dynamic strength of the quadriceps muscle was significantly higher in men than in women, and was positively associated with body weight, years of jogging, years of soccer, and weekly hours of basketball. In conclusion, the dynamic strength of the quadriceps muscle seems to be associated with sports activity. The results suggest sport specific adaptation, which may reflect high levels of running and jumping activity.
Adaptation, Physiological↗
A pilot study comparing the effects of spinal manipulative therapy with those of extra-spinal manipulative therapy on quadriceps muscle strength.
OBJECTIVE: The objective of this study was to assess whether tibiofemoral joint manipulation is as effective as sacroiliac (SI) joint manipulation in increasing quadriceps muscle strength. DESIGN AND SETTING: Twenty subjects were divided into two groups of 10. After all base measurements of the maximum voluntary force of the quadriceps muscles were taken, subjects in group A received tibiofemoral joint manipulation and those in group B received ipsilateral SI joint manipulation. After these treatments, the maximum voluntary forces of the subjects' quadriceps muscles were retested. RESULTS: A significant improvement (P = .05) in quadriceps muscle strength was noted in the subjects who received an SI joint manipulation. CONCLUSION: This study showed a significant change within the SI joint manipulation group before and after the manipulation but did not show any significant difference between the groups (tibiofemoral joint vs SI joint manipulation) in increasing quadriceps muscle strength.
Adult↗
Timing of surgery in acute anterior cruciate ligament tears on the return of quadriceps muscle strength after reconstruction using an autogenous patellar tendon graft.
To determine if patients who delayed anterior cruciate ligament reconstruction until a convenient time regained quadriceps muscle strength allowing them to return to sports participation at a different rate than patients who had early surgery for anterior cruciate ligament reconstruction, we studied 143 patients who had the same surgical procedure and postoperative rehabilitation program. Group I delayed surgery at a mean of 40 days after injury; Group II had early surgery at a mean of 11 days after injury. Statistically, Group I patients had significantly better mean quadriceps muscle strength at 2 months (P = 0.017) and at 4 months (P = 0.0055) postoperatively. At least 65% quadriceps muscle strength was achieved by 40 of the 50 patients (80%) tested in Group I at 2 months, allowing the patients to progress to sport-specific rehabilitation. Only 35 of the 66 patients (53%) tested in Group II were able to progress toward sports activities at 2 months. By 6 months, 29 of the 40 patients (73%) tested in Group I compared with 27 of the 58 patients (47%) tested in Group II had 80% quadriceps muscle strength. This study demonstrates that the return of quadriceps muscle strength was faster for our patients who delayed anterior cruciate ligament reconstruction than for our patients who had early reconstruction. Thus, despite delaying their early reconstructions, Group I was able to progress sooner from the date of surgery to sport-specific rehabilitation.
Acute Disease↗
Hemodynamics and O2 uptake during maximal knee extensor exercise in untrained and trained human quadriceps muscle: effects of hyperoxia.
To elucidate the potential limitations on maximal human quadriceps O2 capacity, six subjects trained (T) one quadriceps on the single-legged knee extensor ergometer (1 h/day at 70% maximum workload for 5 days/wk), while their contralateral quadriceps remained untrained (UT). Following 5 wk of training, subjects underwent incremental knee extensor tests under normoxic (inspired O2 fraction = 21%) and hyperoxic (inspired O2 fraction = 60%) conditions with the T and UT quadriceps. Training increased quadriceps muscle mass (2.9 +/- 0.2 to 3.1 +/- 0.2 kg), but did not change fiber-type composition or capillary density. The T quadriceps performed at a greater peak power output than UT, under both normoxia (101 +/- 10 vs. 80 +/- 7 W; P < 0.05) and hyperoxia (97 +/- 11 vs. 81 +/- 7 W; P < 0.05) without further increases with hyperoxia. Similarly, thigh peak O2 consumption, blood flow, vascular conductance, and O2 delivery were greater in the T vs. the UT thigh (1.4 +/- 0.2 vs. 1.1 +/- 0.1 l/min, 8.4 +/- 0.8 vs. 7.2 +/- 0.8 l/min, 42 +/- 6 vs. 35 +/- 4 ml x min(-1) x mmHg(-1), 1.71 +/- 0.18 vs. 1.51 +/- 0.15 l/min, respectively) but were not enhanced with hyperoxia. Oxygen extraction was elevated in the T vs. the UT thigh, whereas arteriovenous O2 difference tended to be higher (78 +/- 2 vs. 72 +/- 4%, P < 0.05; 160 +/- 8 vs. 154 +/- 11 ml/l, respectively; P = 0.098) but again were unaltered with hyperoxia. In conclusion, the present results demonstrate that the increase in quadriceps muscle O2 uptake with training is largely associated with increases in blood flow and O2 delivery, with smaller contribution from increases in O2 extraction. Furthermore, the elevation in peak muscle blood flow and vascular conductance with endurance training seems to be related to an enhanced vasodilatory capacity of the vasculature perfusing the quadriceps muscle that is unaltered by moderate hyperoxia.
Adult↗
Decrease in human quadriceps muscle protein turnover consequent upon leg immobilization.
Quadriceps muscle protein turnover was assessed in the post-absorptive state in six men immediately after the end of unilateral leg immobilization (37 +/- 4 days) in a plaster cast after tibial fracture. A primed-constant intravenous infusion of L-[1-13C]leucine was administered over 7 h. Quadriceps needle biopsies, taken bilaterally at the end of the infusion, were analysed for muscle protein leucine enrichment with 13C. Quadriceps muscle protein synthetic rate, calculated from the fractional incorporation of [13C]leucine into protein compared with the average enrichment of blood alpha-ketoisocaproate, was 0.046 +/- 0.012%/h in the uninjured leg, but was only 0.034 +/- 0.007%/h in the quadriceps of the previously fractured leg (P less than 0.05, means +/- SD). Muscle RNA activity (i.e. protein synthetic rate per RNA) fell from 0.27 +/- 0.08 microgram of protein synthesized h-1 microgram-1 of RNA in the control leg to 0.14 +/- 0.03 microgram of protein synthesized h-1 microgram-1 of RNA in the immobilized leg (P less than 0.02). Immobilization was associated with a significant atrophy of type I muscle fibres (mean diameter 69.5 +/- 21 microns immobilized, 81.1 +/- 18 microns control, P less than 0.05), but no significant change occurred in type II fibre diameter. Mean quadriceps fibre volume calculated from the values for fibre diameter and percentage of each fibre type, was smaller in the injured leg by 10.6%; this value was near to the calculated difference in muscle thigh volume (calculated from thigh circumference and skin-fold thickness) which was less by 8.3%.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Effect of exercise-induced arterial hypoxemia on quadriceps muscle fatigue in healthy humans.
The effect of exercise-induced arterial hypoxemia (EIAH) on quadriceps muscle fatigue was assessed in 11 male endurance-trained subjects [peak O2 uptake (VO2 peak) = 56.4 +/- 2.8 ml x kg(-1) x min(-1); mean +/- SE]. Subjects exercised on a cycle ergometer at >or=90% VO2 peak) to exhaustion (13.2 +/- 0.8 min), during which time arterial O2 saturation (Sa(O2)) fell from 97.7 +/- 0.1% at rest to 91.9 +/- 0.9% (range 84-94%) at end exercise, primarily because of changes in blood pH (7.183 +/- 0.017) and body temperature (38.9 +/- 0.2 degrees C). On a separate occasion, subjects repeated the exercise, for the same duration and at the same power output as before, but breathed gas mixtures [inspired O2 fraction (Fi(O2)) = 0.25-0.31] that prevented EIAH (Sa(O2) = 97-99%). Quadriceps muscle fatigue was assessed via supramaximal paired magnetic stimuli of the femoral nerve (1-100 Hz). Immediately after exercise at Fi(O2) 0.21, the mean force response across 1-100 Hz decreased 33 +/- 5% compared with only 15 +/- 5% when EIAH was prevented (P < 0.05). In a subgroup of four less fit subjects, who showed minimal EIAH at Fi(O2) 0.21 (Sa(O2) = 95.3 +/- 0.7%), the decrease in evoked force was exacerbated by 35% (P < 0.05) in response to further desaturation induced via Fi(O2) 0.17 (Sa(O2) = 87.8 +/- 0.5%) for the same duration and intensity of exercise. We conclude that the arterial O2 desaturation that occurs in fit subjects during high-intensity exercise in normoxia (-6 +/- 1% DeltaSa(O2) from rest) contributes significantly toward quadriceps muscle fatigue via a peripheral mechanism.
Adult↗
Congenital contracture of the quadriceps muscle: a case report with magnetic resonance imaging.
INTRODUCTION: Case report of a rare form of congenital contracture of the quadriceps muscle. Congenital contracture of the quadriceps muscle is encountered very rarely in daily orthopaedic practice. A few cases have been reported, but unfortunately these did not detail the MRI findings of congenital contracture. MATERIALS AND METHODS: A 34-year-old woman presented with difficulty in sitting with full flexion of the bilateral knee joints. She had no history of intramuscular injection, and her brother had a similar abnormality. A physical and radiographical review of the case was conducted. RESULTS: A palpable corded induration was detected in the quadriceps muscle which prevented further flexion of the bilateral knee joints. Magnetic resonance imaging of both thighs demonstrated marked atrophy of the rectus femoris muscle and dark signal intensity of the muscle on both T1-weighted and T2-weighted images. It was suggested that the muscles had been replaced by fibrosis. CONCLUSION: This appears to be the first report to include MRI findings of congenital contracture. Clinical awareness of congenital contracture with unique clinical symptoms and radiographic findings may aid the correct diagnosis.
Adult↗
Quadriceps muscle wasting persists 5 months after total hip arthroplasty for osteoarthritis of the hip: a pilot study.
AIMS: To determine whether additional muscle fibre wasting of the ipsilateral vastus lateralis muscle occurs in the early postoperative period after total hip arthroplasty for osteoarthritis of the hip and whether there is an improvement in preoperative measures of quadriceps muscle thickness, strength, pain and function over a 5-month postoperative period. METHODS: Twelve patients had ipsilateral needle quadriceps biopsy for muscle morphology and bilateral quadriceps muscle thickness ultrasound preoperatively, 5 days and 4 weeks postoperatively and a further muscle thickness measurement at 5 months. Seven additional patients and five age-matched control subjects had bilateral quadriceps muscle ultrasound thickness preoperatively, 6 weeks and 5 months postoperatively, with assessment of quadriceps muscle dynamometry, pain scores and Timed Up and Go (TUG) test. RESULTS: Preoperatively, all 19 patients demonstrated significant atrophy of the ipsilateral compared with the contralateral quadriceps muscle (P = 1.8 x 10(-7)) on muscle ultrasound, which persisted at 5 months follow up (P = 0.009). Muscle morphology preoperatively showed type 2A and 2B muscle fibre atrophy on needle muscle biopsy, with further atrophy of all three fibre types (P = 0.029) at 5 days postoperatively associated with a fibre type shift from type 1 to 2A fibres (P = 0.0011) at 1 month. There was improvement in hip pain postoperatively and a significant improvement in the TUG test (P = 0.007). However, there was no improvement in muscle strength on dynamometry. CONCLUSIONS: There is significant ipsilateral quadriceps atrophy and weakness with 2A and 2B fibre atrophy preoperatively in patients with osteoarthritis of the hip with exacerbation and further atrophy of all three fibre types 5 days postoperatively. Postoperative follow up showed that the reduction in ipsilateral quadriceps muscle thickness persisted at 5 months despite physical rehabilitation. Patients did note significant improvement in pain postoperatively and improvement on functional assessment with the TUG test. Other therapeutic strategies may have to be developed to reverse disuse muscle atrophy.
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