Thigh Extensor Research Articles

Physiatric treatment of hip dysplasia in a puppy: Case report

Hip dysplasia is a highly recurrent orthopedic condition that starts in the puppy with joint laxity and progresses to osteoarthrosis, which can cause severe pain and compromise the animal's quality of life. Its development is multifactorial and there are several described. In adults, there is a consensus that the treatment of the disease is multifactorial and encompasses environmental management, use of nutraceuticals, anti-inflammatories, and physical therapy. When there is no response the treatment, surgical procedures such as acetabular denervation, arthroplastic excision of the femoral head and total hip replacement can be performed. In puppies there are already studies that prove the hormonal, nutritional influence, and the development of muscle mass in the evolution of hip dysplasia. However, there is no previous report of a physiatric protocol for dysplastic puppies. Conservative treatment was performed on a male dog of the Saint Bernard breed with a severe degree of hip subluxation and valgus angular deviation from 4 to 9 months of age. With the application of functional electrostimulation, kinesiotherapy and photobiomodulation during 30 sessions, there was a significant improvement in muscular and cardiovascular resistance, an important reduction in claudication, muscle mass gain in the gluteal region and thigh extensors, reduction of angular deviation of the femorotibial joint and it was easier for it to stand up. It is concluded that physiatric techniques have the potential to control the factors that negatively influence the development of hip dysplasia and can be included in the conservative treatment in puppies, however further studies are needed.

Coronavirus disease 2019 and frailty

Der Verlauf der Coronavirus disease 2019 (COVID-19) ist individuell sehr unterschiedlich. Menschen höheren Lebensalters mit Komorbiditäten sind gefährdeter, schwer zu erkranken oder zu versterben. Gebrechlichkeit (Frailty) ist ein wesentlicher Risikofaktor. Ein Fünftel der Bevölkerung in Mitteleuropa ist älter als 65 Jahre, 10–15 % davon sind als „frail“ anzusehen. Die Pandemie bringt die Gesundheitssysteme vieler Länder an deren Grenzen. Die Entscheidung, welche Patienten noch intensivmedizinisch behandelt werden, führt zu ethischen Diskussionen. Die Clinical Frailty Scale von Rockwood (CFS; CMAJ 173:489–495, 2005) wird in manchen Ländern eingesetzt, diese Entscheidungen zu unterstützen.Von COVID-19 betroffene 80-jährige Patienten haben ein fast 3,6faches Sterblichkeitsrisiko, verglichen mit der Altersgruppe von 18 bis 49 Jahren. Das Risiko gebrechlicher Patienten (CFS-Scores 6–9) ist mehr als 3fach höher als von robusten (CFS-Scores 1–3). Ein CFS-Cut-off-Wert ≥ 6 korreliert mit der Mortalität von COVID-19-Patienten über 65 Jahre. Das mittel- und längerfristige Überleben ist auch mit dem Ausmaß von „Frailty“ vor der Erkrankung und weniger mit dem Schweregrad der COVID-19 assoziiert.Besonders Patienten über 60 Jahre sind gefährdet, bei moderaten und schweren COVID-19-Verläufen rasch Muskelmasse zu verlieren. Patienten auf Intensive Care Units (ICU) verlieren innerhalb von 10 Tagen 20–30 % der Oberschenkelstreckmuskulaturmasse. Das Ausmaß der COVID-19-assoziierten Sarkopenie bestimmt wesentlich den Verlauf der Erkrankung und macht individuelle Rehabilitationsprogrammen erforderlich. Bis zu 50 % der hospitalisierten Patienten benötigen weitere Rehabilitation nach der Entlassung. Aerobes Training mit niedriger Intensität, kombiniert mit Krafttraining, sowie die Sicherstellung einer ausreichenden Energie- und Eiweißzufuhr sind unerlässlich.

Prediction of Force Recruitment of Neuromuscular Magnetic Stimulation From 3D Field Model of the Thigh.

Neuromuscular magnetic stimulation is a promising tool in neurorehabilitation due to its deeper penetration, notably lower distress, and respectable force levels compared to surface electrical stimulation. However, this method faces great challenges from a technological perspective. The systematic design of better equipment and the incorporation into modern training setups requires better understanding of the mechanisms and predictive quantitative models of the recruited forces. This article proposes a model for simulating the force recruitment in isometric muscle stimulation of the thigh extensors based on previous theoretical and experimental findings. The model couples a 3D field model for the physics with a parametric recruitment model. This parametric recruitment model is identified with a mixed-effects design to learn the most likely model based on available experimental data with a wide range of field conditions. This approach intentionally keeps the model as mathematically simple and statistically parsimonious as possible in order to avoid over-fitting. The work demonstrates that the force recruitment particularly depends on the effective, i.e., fiber-related cross section of the muscles, and that the local median electric field threshold amounts to about 65 V/m, which agrees well with values for magnetic stimulation in the brain. The coupled model is able to accurately predict key phenomena observed so far, such as a threshold shift for different distances between coil and body, the different recruiting performance of various coils with available measurement data in the literature, and the saturation behavior with its onset amplitude. The presented recruitment model could also be readily incorporated into dynamic models for biomechanics as soon as sufficient experimental data are available for calibration.

Evolution of tendon shape in an anuran clade and its relation to size, phylogeny and locomotion

AbstractMost anatomical specializations related to anuran jumping have been observed in pelvic girdle and hindlimbs, which are characterized by its fused caudal vertebrae and elongated hindlimbs. Still, despite of a greatly specialized body plan, locomotor variation in anurans goes beyond jumping, including specializations for swimming, burrowing, and climbing. Herein, we test for morphological adaptation in three tendinous elements associated with the urostyle and hindlimb joints: the tendon of the longissimus dorsi which inserts on the urostyle and rotates it dorsally; the patellar tendon which goes over the knee joint and connects the larger thigh extensor muscles; and the Achilles tendon which passes over the ankle joint and participates in the catapult‐like mechanism of jumping species. We make an incursion in tendon variation using geometric morphometrics and test if tendon shape is related to size, phylogeny and locomotion in leptodactylid species. Also, we hypothesize that tarsal bone elongation in anura alters the heel into a more ‘knee‐like’ joint affecting tendon shape, and test for patellar and Achilles similarity. We found that a combination of factors drives Leptodactylidae tendon morphological diversity. Allometry, phylogeny and function take part in the longissimus dorsi tendon variation, with significant difference between hopping and all jumping species. The patellar tendon shape scales isometrically with size, with significant shape difference between jumping and jumping‐swimming species. Achilles tendon shape is mainly affected by allometry. Optimization showed a shift for a broader longissimus dorsi tendon shape in the ancestor of Leptodactylus. Finally, and contrary to our prediction, patellar and Achilles tendon shapes are significantly different. Once again, evidence points to a combination of factors explaining shape, rather than a direct and evident functional‐anatomic relation.

지적장애 축구선수들의 하지강화프로그램이 하지근력과 균형능력에 미치는 영향

This study conducted an strengthening legs exercise program with soccer players with intellectual disabilities for 12 weeks to examine the effects on lower extremity strength and balance. The following conclusions were drawn. First, in the change of lower extremity strength before and after strengthening legs exercise program, the exercise group did not show a significant difference in right thigh flexor and left thigh extensor but showed a significant difference in the peak torque of left thigh flexor(p Second, for a change of balance before and after strengthening legs exercise program, the exercise group did not show a significant difference in surface area, travel length, average speed. Taken together, we could see that the strengthening program, which included plyometric training and weight training, had a positive effect. However, it is considered that there is no statistically significant result in the balance ability, so it is necessary to review the constitution of the exercise program. However, if the regular training method and the strengthening program are performed regularly, And it is thought that it can be an effective training method for prevention of injuries.

Isokinetic profile of subjects with the ruptured anterior cruciated ligament.

All changes in the knee that appear after anterior cruciate ligament (ACL) lesion lead to difficulties in walking, running, jumping especially during sudden changes of the line of movement. This significantly impairs quality of life of these subjects and leads to decrease in physical activity. Knee injuries make 5% of all most severe acute sport injuries. The aim of the study was to determine strength of the thigh muscles in persons with unilateral rupture of the ACL and to evaluate potential bilateral differences between healthy and injured leg. This study involved 114 male athletes of different sport specialities with the clinical diagnosis of ACL rupture. Each subject had unilateral ACL rupture and the other leg was actually the control for this research. An isokinetic device was used to evaluate the muscle strength of thigh muscles. Testing was performed for two testing speeds, 60º/s and 180º/s. Data analysis showed a statistically significant difference (p < 0.01) between the ACL and the healthy leg in the following parameters: peak torque for thigh extensors (Ptrq_E), angle to peak torque during extension (Ang_E), power of extension (Pow_E) and work during extension (Work_E). Analysing hamstrings to quadriceps (H/Q) ratio we found the unilateral disbalance of thigh muscle strength in ACL leg. A high level of validity makes isokinetic dynamometry the method for evaluation of thigh muscles strength and leaves this field of research open for new studies in order to improve both diagnostic and rehabilitation of patients with the insufficient ACL.

Quantification of residual limb skeletal muscle perfusion with contrast-enhanced ultrasound during application of a focal junctional tourniquet

Focal junctional tourniquets (JTs) have been developed to control hemorrhage from proximal limb injuries. These devices may permit greater collateral perfusion than circumferential tourniquets. We hypothesized that JTs eliminate large-vessel pulse pressure yet allow a small amount of residual limb perfusion that could be useful for maintaining tissue viability. Ten healthy control subjects were studied. Transthoracic echocardiography, Doppler ultrasound of the femoral artery (FA) and posterior tibial artery, and contrast-enhanced ultrasound (CEU) perfusion imaging of the anterior thigh extensor and calf plantar flexor muscles were performed at baseline and during application of a JT over the common FA. Intramuscular arterial pulsatility index was also measured from CEU intensity variation during the cardiac cycle. FA flow was eliminated by JTs in all subjects; posterior tibial flow was eliminated in all but one. Perfusion measured in the thigh and calf muscles was similar at baseline (0.33 ± 0.29 vs 0.29 ± 0.22 mL/min/g). Application of the JT resulted in a reduction of perfusion (P < .05) that was similar for the thigh and calf (0.08 ± 0.07 and 0.10 ± 0.03 mL/min/g). On CEU, microvascular flux rate was reduced by ≈55%, and functional microvascular blood volume was reduced by ≈35%. Arterial pulsatility index was reduced by ≈90% in the calf. JT inflation did not alter left ventricle dimensions, fractional shortening, cardiac output, or arterial elastance as a measure of total systolic load. Application of a JT eliminates conduit arterial pulse and markedly reduces intramuscular pulse pressure, but thigh and calf skeletal muscle perfusion is maintained at 25% to 35% of basal levels. These data suggest that JTs that are used to control limb hemorrhage allow residual tissue perfusion even when pulse pressure is absent.

The surface-electromyographic characteristics of the anterior and posterior thigh muscles in patients recovering from cerebral infarction

Objective To assess the contraction and coordination changes in the anterior and posterior thigh muscles of patients recovering from cerebral infarction,and to provide objective references for targeted rehabilitation programs. Methods Eighteen cerebral infarction patients with mild hemiparesis (the patient group) and eighteen age- and sex-matched healthy volunteers (the healthy group) were investigated. The surface-electromyographic (sEMG) signals of their vastus medialis,rectus femoris,vastus lateralis,biceps femoris,semitendinosus and semimembranosus were recorded during knee joint flexion and extension in the prone position.The sEMG signals from both legs were recorded for the patient group,but only from the left leg in the healthy group.The standardized root mean square (stRMS) signals and the co-contraction ratios (CRs) were compared and analysed, Results The stRMSs of the rectus femoris,vastus lateralis and vastus medialis on the patients' affected side during knee extension were significantly higher than those in the healthy group at baseline and follow-up.The stRMSs of the biceps femoris and semitendinosus-semimembranous on the patients' unaffected side were significantly higher than those of the affected side and the healthy group during knee flexion at baseline.The CRs during knee flexion on the patientsˊ affected side at baseline and follow-up were significantly higher than those of the unaffected side at baseline. Conclusions After cerebral infarction,the functioning of both the anterior and posterior thigh muscles on the affected side are impaired.The rectus femoris are the most severely impaired knee extensors,and the biceps femoris,semitendinosus and semimembranous are impaired equally in knee flexion.The thigh flexors and extensors lose their normal antagonist-agonist contraction modes.The functions of both the anterior and posterior thigh muscles should be emphasized during rehabilitation to improve abnormal contraction. Key words: Infarction ; Thigh muscles ; Surface-electromyography ; Rehabilitation

Heterotopic ossification following surgical treatment of avulsion fracture of the anterior inferior iliac spine

Avulsion fractures of the anterior inferior iliac spine are rare injuries of the pelvic ring and occur during sports activities. Hereby is presented a case of a 22-year-old professional football player who was diagnosed to have an avulsion fracture of the anterior inferior iliac spine on the right side four months after the initial injury and he was treated surgically with the excision of the avulsed fragment. The football player recovered completely and returned to his usual sports activities. Two years later, due to the pain in the hip an x-ray and MR image were made, which established the existence of crescent formation, a heterotopic bone, in the area of the anterior inferior iliac spine, which was surgically removed. Physical and medical therapy was conducted and after four months, the professional athlete was back playing football. Two years after the surgical excision of heterotopic ossification, the patient was completely asymptomatic with the same ROM without any thigh muscle hypotrophy, although isokinetic muscle testing did show some weakness of the thigh extensor muscles. An x-ray did not show any signs of heterotopic ossification.

Correlation between single-slice muscle anatomical cross-sectional area and muscle volume in thigh extensors, flexors and adductors of perimenopausal women

Quantitative data on muscle volume (MV) are important for estimating maximal muscle power. The objective of this study was to determine the correlation between anatomical cross-sectional areas (ACSAs) and the MV in thigh muscles (extensors, flexors, adductors, and sartorius) in perimenopausal women, and to identify at which proximal-to-distal level a single-slice ACSA measurement with magnetic resonance imaging (MRI) displays the highest correlation in each of these. Axial MRIs of the thigh were acquired in 41 perimenopausal women aged 50.8 +/- 3.2 years. Segmentation of the extensors, flexors, adductors, and the sartorius was performed between the femoral neck (0%) and the distal end of the intermediate vastus (100%). MVs were determined by numerical integration, and the ACSA was calculated from three-dimensional reconstructions at 10% intervals from proximal to distal. The extensors contributed 50%, the flexors 19%, the adductors 28%, and the sartorius 3% of the total thigh MV. Maximal correlations between ACSA and MV were observed at the 20-40% proximal-to-distal level in the extensors (R (2) = 0.73), at 30% in the adductors (R (2) = 0.82), and at 70% in the flexors (R (2) = 0.72) and sartorius (R (2) = 0.85), respectively. ACSA at 50% displayed the highest overall correlations (R (2) >or= 0.69) with MV for all muscle groups. Single-slice ACSAs from MRI displayed high correlations with MVs. Although the (proximal to distal) measurement locations with the highest correlation varied between the muscle groups, a single slice at the 50% location achieved the best compromise in terms of correlation between ACSA and MV across extensors, flexors, adductors and the sartorius.

Relationship between the changes of surface electromyographic signal of thigh muscle and balance function in stroke patients

To explore the relationship between the changes of surface electromyography (sEMG) signal of thigh muscles and balance function in stroke patients during maximum isometric voluntary contraction (MIVC) of knee extension and flexion so as to provide rationales for rehabilitation. Twenty-one stroke patients and 18 age- and sex-matched normal controls were recruited for this study. The surface electromyographic signals of of vastus medialis (VM), rectus femoris (RF), vastus lateralis (RL) and biceps femoris (BF) were recorded during MIVC of knee extension and flexion. Root mean square (RMS) and co-contraction ratio (CR) of both groups were compared and analyzed. The balance function was assessed by Berg balance scale (BBS). There were significant differences in RMS of VM, RF, VL and BF of ipsilateral [(136 +/- 63) microV, (107 +/- 24) microV, (154 +/- 19) microV, (91 +/- 63) microV], thigh during knee extension and flexion (P < 0.05). There were significant differences in CR on ipsilateral thigh muscles than the unaffected (43% +/- 13% vs 37% +/- 20%) and controls (43% +/- 13% vs 32% +/- 10%) during knee flexion (P < 0.05). The RMS of RF and BF on ipsilateral thigh was significantly positively correlated with the score of BBS (rRF = 0.53, P = 0.01 vs rBF = 0.51, P = 0.02); The CR of knee extension and flexion on ipsilateral thigh had a significantly negative correlation (CRE = -0.59, P = 0.005 vs. CRF = -0.41, P = 0.046). The strength of bilateral thigh muscles decreases in stroke patients. The spasticity of thigh extensor still exists. Besides reducing the spasticity of hemiplegic limb extensor, rehabilitation should also focus upon bilateral thigh muscles, particularly ipsilateral RF and BF strength training to improve the knee joint stability and improve the balance function.

Pelvic and thigh musculature in frogs (Anura) and origin of anuran jumping locomotion

Comparative analysis of the anuran pelvic and thigh musculoskeletal system revealed that the thigh extensors, responsible for the initial phase of jump, the propulsive stroke in swimming and, if used asynchronously, also for walking, are least affected by the transformations observed between anurans and their temnospondyl ancestors (as reflected in contemporary caudates). The iliac shaft and urostyle, two of the most important anuran apomorphies, represent skeletal support for muscles that are mostly protractors of the femur or are important in attaining a crouching position, a necessary prerequisite for rapid escape. All of these muscles originate or insert on the iliac shaft. As the orientation of the pubis, ischium and ilium is the same in anurans, caudates and by inference also in their temnospondyl ancestors, it is probable that the pelvis was shifted from the sacral vertebra posteriorly along the reduced and stiffened tail (urostyle) by the elongation of the illiac shaft. Thus, the original vertical orientation of the ilium was maintained (which is also demonstrated by stable origins of the glutaeus maximus, iliofemoralis and iliofibularis on the tuber superius) and the shaft itself is a new structure. A review of functional analysis of anuran locomotion suggests some clear differences from that in caudates, suggesting that terrestrial jumping may have been a primary locomotor activity, from which other types of anuran locomotion are derived.

肥満中年女性の身体組成に及ぼす複合トレーニングとタンパク質摂取の併用効果

The purpose of this study was to investigate the effects of combined resistance training and aerobic training with protein intake after resistance training on body composition in obese middle-aged women. The subjects were 42 middle-aged women (age : 56.5±4.3 years, BMI : 26.6±2.3 kg/m2), who were classified into three supplementation groups: Protein group (PG), Isocalorie placebo group (IG), and Noncalorie placebo group (CG) by Double Blind Randomized Trial. The training program consisted of combined resistance training and aerobic training for 10 weeks, 5 times per week: twice a week in a university training room and 3 times per week at home. The subjects took the nutrient supplement immediately after each resistance training session. We measured body weight (Bw), body fat volume (Bf) by bioelectrical impedance analysis (BIA), and cross-sectional area (CSA) of muscle of the thigh extensor group (Te), flexor group (Tf), and psoas major (Pm) by magnetic resonance imaging (MRI) before and after the 10-week training period. Irrespective of group, Bw and Bf showed a significant decrease after the training period compared to before (p<0.001), and the CSA of Te muscle showed a significant increase after the training period (p<0.01). Moreover, the interaction of time×group was accepted in the CSA of Pm muscle (p<0.05), and the increase in muscle volume for PG was the highest increase among the three supplementation groups (p<0.05)(PG : 2.1±0.8 cm2, IG : 1.3±1.0 cm2, CG : 1.3±0.9 cm2). These results suggest that combined training in middle-aged obese women improves body composition, and resistance training with protein intake may increase the CSA of muscle of psoas major.

Effects of rhythmic muscle compression on cardiovascular responses and muscle oxygenation at rest and during dynamic exercise

We examined the way in which the duration of rhythmic muscle compressions affects cardiovascular responses and muscle oxygenation at rest and during dynamic exercise. We measured the mean arterial pressure (MAP), heart rate (HR) and oxygenation of the vastus lateralis muscle (by near-infrared spectroscopy) in eight healthy male subjects at rest and during supine bicycle exercise (50 and 100 W at 60 r.p.m.) while applying pulsed muscle compressions at 1000 ms intervals. Compression pressure and durations were 150 mmHg and 300, 600, 900 and 1000 ms (1000 ms being static continuous compression), respectively. During exercise, the pulsed leg compression was synchronized to each thigh extensor muscle contraction. The observed changes in muscle oxygenation were dependent on compression duration (increased at 300 ms, no change at 600 ms and decreased at 900 or 1000 ms) and were different from those seen at rest (increases at < 1000 ms and decrease at 1000 ms). This suggests that the effects of external pulsed muscle compression may have a duration threshold below which muscle pumping counteracts the obstruction to flow caused by the compression, and that the threshold is set at a shorter compression duration during exercise than at rest. Although HR and MAP did not change during pulsed compression at rest, during exercise they both increased progressively as compression duration increased. Thus, while exercising, the increased MAP and HR seen during the compression could be due to the combination and interaction of mechanical effects and the muscle mechanoreflex and/or metaboreflex.

Effects of rhythmic muscle compression on arterial blood pressure at rest and during dynamic exercise in humans.

This study was designed to examine the hypothesis that a rhythmic mechanical compression of muscles would affect systemic blood pressure regulation at rest and during dynamic exercise in humans. We measured the changes in mean arterial pressure (MAP) occurring (a) at rest with pulsed (350 ms pulses at 50 pulses min(-1)) or static compression (50 and 100 mmHg) of leg muscles with or without upper thigh occlusion, and (b) during 12-min supine bicycle exercise (75 W, 50 r.p.m.) with or without pulsed compression (50, 100, 150 mmHg) of the legs in synchrony with the thigh extensor muscle contraction. At rest with thigh occlusion, MAP increased by 4-8 mmHg during static leg compression, and by 5-9 mmHg during pulsed leg compression. This suggests that at rest pulsed leg compression elicits a reflex pressor response of similar magnitude to that evoked by static compression. During dynamic exercise without leg compression, MAP (having risen initially) gradually declined, but imposition of graded pulsed leg compression prevented this decline, the MAP values being significantly higher than those recorded without pulsed leg compression by 7-10 mmHg. These results suggest that the rhythmic increase in intramuscular pressure that occurs during dynamic exercise evokes a pressor response in humans.

Maximal instantaneous muscular power after prolonged bed rest in humans.

A reduction in lower limb cross-sectional area (CSA) occurs after bed rest (BR). This should lead to an equivalent reduction in maximal instantaneous muscular power (W(p)) if the body segments' lengths remain unchanged. W(p) was determined during maximal jumps off both feet on a force platform before and on days 2, 6, 10, 32, and 48 after a 42-day duration BR. CSA of thigh muscles was measured by magnetic resonance imaging before and on day 5 after BR. Before BR, W(p) was 3.63 +/- 0.43 kW or 48.6 +/- 3.3 W/kg. On days 2 and 6 after BR, W(p) was reduced by 23.7 +/- 6.9 and 22.7 +/- 5.4% (P < 0.01), respectively. Thigh extensors CSA (CSAEXT) was 16.7 +/- 4.7% (P < 0.01) lower than before. When normalized per CSAEXT, W(p) was reduced by only 4.8 +/- 4.5% (P < 0.05). By day 48 of recovery, W(p) had returned to baseline values. Therefore, if W(p) is appropriately normalized for CSA of the extensor muscles, the reduction in CSAEXT explains most of the decrease in W(p) decrease after BR. Other factors such as a deficit in neural activation or a decrease in fiber-specific tension may account for only 5% of the W(p) loss after BR.

加齢による下肢筋量の低下が歩行能力に及ぼす影響

The purpose of this study was to investigate the hypothesis that the reduction in walking ability is due to muscle atrophy in the lower limb muscles with aging using equational structure modeling as well as investigate the influence of muscle on walking ability. The subjects consisted of 127 persons (57 males and 70 females) aged 20-84 year, who were grouped into 6 age brackets of 20-39, 40-49, 50-59, 60-69, 70-74, and 75 or older. Using MRI, muscle cross-sectional area was measured on psoas major and thigh muscle (divided into extensor and flexor) . For walking patterns, each subject walked along a 7-m walking passage at normal speed for VTR-recording of the motion. The resulting pictures were used to analyze stride length, trunk inclination and walking speeds. Walking speeds showed a statistically significant decrease in value from the 50's age group in males and the 60's age group in females when compared with the 20-39 age bracket (p<0.05) . In males, a significant co-relationship was observed only between the muscle cross-sectional area of thigh extensor and walking speed (p<0.01) while in females, a significant co-relationship was found between the muscle cross-sectional area of psoas major (p<0.001) /thigh muscle extensor (p<0.01) and walking speed. These results indicate that the muscle atrophy with aging in psoas major and thigh muscle extensor is a factor responsible for the decrease in walking speed. Meanwhile, a difference in sex was observed between the muscle cross-sectional area of psoas major and walking speed. It was considered that the muscle atrophy rate of the female's psoas major being higher than the male's influenced this. Furthermore, it was suggested possibility that the decline of walking ability is due to decreased muscle mass of the lower limbs with aging.

RELATIONSHIPS OF MUSCULAR STRENGTH TO LUMBAR AND FEMUR BONE MINERAL DENSITY IN HEALTHLY WOMEN

1081 The purpose of this study was to evaluate the relationships of back strength, Thigh strength and handgrip strength to lumbar and femur bone mineral density(BMD) in 754 healthy women(mean age 47.29±7.96). BMD of the 2nd, 3rd, 4th lumbar vertebrae and femural neck were measured by dual energy X-ray absorptiometer (DEXA). Thigh strength and back strength were examined with cybex 6000 system and MedX lumbar extension machine, respectively, and handgrip strength was determined by handgrip dynamometer. The BMD of lumbar(LMBD) correlated with back strength(r=.53, p<.01), age(−.45,p<.01), thigh extensor strength(r=.39, p<.01), body weight(r=.32, p<.01), handgrip strength(r=.31, p<.01), and thigh flexor strength(r=.30, p<.01) and the BMD of femur(FBMD) correlated with age(r=−.43, p<.01), thigh extensor strength(r=.43, p<.01), back strength(r=.40, p<.01), thigh flexor strength(r=.3 4, p<.01), handgrip strength(r=.32, p<.01), and body weight(r=.28, p<.01). By backward multiple regression, the LBMD is affected by age, body weight, and back strength(p<.0001), and the FBMD is affected by age, body weight, thigh extensor and back strength(p<.0001). A multiple regression analysis yielded the following formula for predicted BMD: LBMD=0.9637−0.00772 × age+0.00484×body weight+0.00032×back strength., FBMD=0.7721−0.0057× age+0.0032 × body weight+0.00 18 × thigh extensor strength+0.00012 × back strength. This study suggest that there is close relationship between muscle strength and loss of bone mineral.

Incipient compartment syndrome of the thigh following total knee arthroplasty

Compartment syndrome of the thigh is in itself a rarity because of the large size of the compartment and the relatively high compliance of the thigh which allows accommodation to volume changes due to hematoma or tissue edema. Most cases have been reported in association with impact trauma to the lower extremity or in association with crush syndrome. A previously unrecognized complication of total knee arthroplasty where an incipient compartment syndrome developed in the thigh extensor compartment is reported.

Age-Related Differences in the Effects of Isokinetic Training on Muscle Strength and Endurance for Thigh Muscles

This study was designed to investigate age-related differences in isokinetic peak torque and its endurance on normal 172 boys ranging in age from 10 to 18 years served as volunteer subjects. Each subject was given a leg extension/flexion test using an isokinetic dynamometer (Cybex II), and extended/flexed at every speed of 0°, 60°, 120°, 180°, 240° and 300°/sec to measure the peak torque of thigh muscles estimated as muscle strength. He was also given an endurance test used the above Cybex II and extended maximally a leg at 180°/sec, 50 times, An endurance of thigh muscles was calculated as a ratio of (mean value for peak torque of initial 5 times-mean value of final 5 times)/mean value of initial 5 times.The peak torque, measured in the extension/flexion test, clearly increased in order of age. In the endurance test, the initial mean value for peak torque was in almost the same developing pattern as those described above in the leg extension/flexion test, but the final mean value did not respond to age over 16 years old.Therefore, 96 boys, aged 11 to 15 years old organized five age groups, and individual group was divided into two subgroups, i, e, experimental group and control group. The members in the experimental group participated in an isokinetic muscle training used Cybex II, consisted of 3 days/week, and 3 sets/day (1 set was 30-times repetition at 180°/sec) throughout 8 weeks.The training increased considerably the strength and endurance of thigh muscles for boys ages 13 years, compared to another age group. Boys aged 14 and 15 years had a larger increment of muscle strength through the training than 11 and 12 years old boys. Boys of 12 years, however, showed a comparable increase in muscle endurance through the training to those aged 14 and 15 years.As above showed, it was discernible that the effects of training on the muscle strength and endurance generally depended on physical maturing.The effect on muscle strength of thigh flexors through the training was greater than that of thigh extensor, independently of age.The improvement of muscle strength was caused by muscle hypertrophy and neurological factor, especially the latter regardless of age, irrespective of the influence due to hypertrophy extended from 10.3% at the age of eleven to 19.1% at the age of fifteen.