SEARCH · PubMed Health

Results for “Hamstring Muscles”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 847 records · Page 47Linked to original sources

PubMed2000

[Electric stimulation in muscle training of the lower extremities in persons with spinal cord injuries].

Spinal cord injured persons have limited possibilities to perform physical training. By use of computerized, feed-back controlled electrical stimulation of the gluteal, the hamstrings and the quadriceps muscles cycle ergometry can be performed by the spinal cord injured individual. The cardiovascular demands of this training is higher than with voluntary upper body training using the intact innervated muscles. The inactivity related conditions caused by the spinal cord injury are reversed in part by regular electrically stimulated training. An increase is seen in maximal oxygen consumption, in the insulin stimulated glucose uptake and in the muscular mass and bone mineral content of the lower extremities. Electrically induced cycle ergometry is thoroughly investigated, relatively safe, but time consuming. As this training in addition results in the same well being as seen by training in able bodied individuals it can be recommended for motivated patients.

Electric Stimulation Therapy↗

PubMedDate not supplied

Relevance of the popliteal angle to hamstring length in cerebral palsy crouch gait.

The popliteal angle is a widely used clinical means of assessing hamstring length in cerebral palsy patients. The relevance of the popliteal angle as a measure of hamstring length was assessed in this prospective study. Sixteen patients with cerebral palsy with crouch gait had their conventional and modified popliteal angles measured by nine observers on two separate occasions. With use of the conventional and modified forms of the test, 74 and 70%, respectively, of the observed variability was inter-and intraobserver related. The range of SDs for each observer using the conventional test was 7.1-13.6 degrees (average 10.9 degrees ), and with use of the modified form of the test, the range was 6.3-4.2 degrees (average 10.5 degrees ). The maximum hamstring length of each subject during gait was determined by three-dimensional modelling of their lower limbs. The modified popliteal angle measurements of the most repeatable observer demonstrated an inverse relationship between modified popliteal angle and maximum hamstring length (p < 0.01) and muscle excursion (p < 0.01). Only 10 of 32 limbs had short medial hamstrings.

Adolescent↗

PubMed1985

In vivo moment arm lengths for hip extensor muscles at different angles of hip flexion.

Moment arm lengths of three hip extensor muscles, the gluteus maximus, the hamstrings and the adductor magnus, were determined at hip flexion angles from 0 degrees to 90 degrees by combining data from ten autopsy specimens and from twenty patients, the latter examined by computed tomography. A straight-line muscle model for muscle force was used for the hamstrings and adductor magnus, and for the gluteus maximus a two-segment straight-line muscle force model was used. With the joint in its anatomical position the moment arm of the gluteus maximus to the bilateral motion axis averaged 79 mm, for the hamstrings 61 mm and for the adductor magnus 15 mm. The moment arm of gluteus maximus decreased with increasing hip flexion angle. The hamstrings showed an increase in moment arm length up to an average of 35 degrees hip flexion and then a decrease with increasing hip flexion angle. The corresponding figures for the adductor magnus moment arm showed an increase up to 75 degrees and then a decrease. Statistical analysis revealed significant differences in moment arm length between men and women.

Aged↗

PubMed2004

A survey of flexibility training protocols and hamstring strains in professional football clubs in England.

OBJECTIVES: To investigate the relation between current flexibility training protocols, including stretching, and hamstring strain rates (HSRs) in English professional football clubs. METHOD: Questionnaire based data on flexibility training methods and HSRs were collected from 30 English professional football clubs in the four divisions during the 1998/99 season. Data were coded and analysed using cross tabulation, correlation, and multiple regression. RESULTS: Flexibility training protocols were characterised by wide variability, with static stretching the most popular stretching technique used. Hamstring strains represented 11% of all injuries and one third of all muscle strains. About 14% of hamstring strains were reinjuries. HSRs were highest in the Premiership (13.3 (9.4)/1000 hours) with the lowest rates in Division 2 (7.8 (2.9)/1000 hours); values are mean (SD). Most (97%) hamstring strains were grade I and II, two thirds of which occurred late during training/matches. Forwards were injured most often. Use of the standard stretching protocol (SSP) was the only factor significantly related to HSR (r = -0.45, p = 0.031) in the correlation analysis, suggesting that the more SSP is used, the lower the HSR. About 80% of HSR variability was accounted for by stretching holding time (SHT), SSP, and stretching technique (STE) in the multiple regression equation: HSR = 37.79 - (0.33SHT + [corrected] 10.05SSP + 2.24STE) +/- 2.34. SHT (negatively correlated with HSR) was the single highest predictor, and accounted for 30% of HSR variability, and an additional 40% in combination with SSP. CONCLUSIONS: Flexibility training protocols in the professional clubs were variable and appeared to depend on staffing expertise. Hamstring stretching was the most important training factor associated with HSR. The use of SSP, STE, and SHT are probably involved in a complex synergism which may reduce hamstring strains. Modification of current training patterns, especially stretching protocols, may reduce HSRs in professional footballers.

England↗

PubMed2000

A comparison of lower extremity muscle strength, obesity, and depression scores in elderly subjects with knee pain with and without radiographic evidence of knee osteoarthritis.

OBJECTIVE: To determine, in subjects with knee pain but no radiographic changes of tibiofemoral or patellofemoral compartment osteoarthritis (OA), whether mean body weight, quadriceps and hamstring strength, lower extremity muscle mass, depression scores, and perceptions of their general health status differed from those of subjects with symptomatic knee OA. METHODS: Subjects were 25 women and 10 men with knee pain and radiographic evidence of OA at the baseline examination, and 21 women and 16 men who had knee pain at the baseline examination but no radiographic evidence of knee OA at either baseline examination or followup evaluation performed, on average, 31 months later. These individuals were a subset of a cohort of 462 independently living elderly individuals recruited by telephone interview after random selection through random digit dialing of households in central Indiana. Data from an additional 134 subjects who had neither knee pain nor radiographic changes of OA at either the baseline or followup examination were analyzed for comparison. Lower extremity muscle strength was measured by isokinetic dynamometry, lean tissue (i.e., muscle) mass in the lower extremities by dual x-ray absorptiometry, depression by Center for Epidemiology Depression (CES-D) scale. knee pain by Western Ontario McMaster University OA instrument, and perceived general health status by the Medical Outcome Survey Short Form-36. RESULTS: In contrast to those with symptomatic knee OA, those who had knee pain but no radiographic evidence of OA were less obese, had hamstring as well as quadriceps weakness, and had CES-D scores high enough to qualify for a diagnosis of clinical depression. CONCLUSION: Among subjects with knee pain but no OA--and among women in this subset, in particular--knee pain may be a manifestation of depression. rather than of joint disease.

Aged↗

PubMed2002

The importance of posture on the isokinetic assessment of spasticity.

OBJECTIVE: To measure spasticity of the knee flexors and extensor muscles in two different hip positions. SETTING: Swiss Paraplegic Center Nottwil, Switzerland. METHODS: Twenty spinal cord injured (SCI) patients with complete lesions were tested with a torque-velocity dynamometer in the following positions: (1) supine with a hip angle of 0 degrees; (2) sitting with a hip angle of 90 degrees. The excursion of the knee was measured for both positions using a goniometer. Two flexion/extension movements of the knee were performed at a speed of 10 degrees per sec. A further four flexion/extension movements over the same trajectory were made at a speed of 120 degrees per sec. Eccentric peak torques were measured continuously during movement of both legs for both speeds. RESULTS: At a speed of 120 degrees per second, there was a significant difference in stretch reflex of the hamstrings and quadriceps femoris muscles for the two positions (Wilcoxon's paired t-test, P<0.05). Excitability was higher for the quadriceps femoris muscles in supine than in sitting position. For the hamstrings, the effect was reversed. Significant differences between sitting and supine position were not found for the speed of 10 degrees per sec. Test-retest reliability was high for the movements of 120 degrees per sec but low for 10 degrees per sec. CONCLUSIONS: Our findings indicate that for a reliable and comparable measurement of spasticity, an exact description of test position and procedure is essential.

Adult↗

PubMed2006

Facioscapulohumeral muscular dystrophy with severe mental retardation and epilepsy.

We report here a case of a 20-year-old woman with facioscapulohumeral muscular dystrophy (FSHD). In this patient, the involvement of facial muscle had been present since early childhood, but obscured due to the complication of profound mental retardation. Epilepsy emerged at eight years of age. Symmetrical limb muscle weakness appeared at 15 years of age, which progressed such that she was wheelchair-bound at 18 years of age. An elevated serum creatine kinase, predominant involvement of hamstrings, scapular and abdominal muscles, as well as an impaired stapedial reflex at high tune, were compatible with the clinical features of FSHD. The diagnosis of 4q35-FSHD was confirmed by detection of a 10kb EcoRI fragment with a p13E-11 probe on a Southern blot. The intellectual disability in this patient was the most severe of all FSHD patients reported to date and has hindered a correct diagnosis. This entity should be included in the differential diagnoses for patients with muscular symptoms and accompanying mental retardation.

Adult↗

PubMed2005

[Women's soccer. Injuries, risks, and prevention].

Women's soccer participation is becoming a trend in sport. With increasing number of licensed female soccer players, there is also an increase in sport specific injuries. This fact has socioeconomic importance. The larger pelvic bone leading to an increased internal rotation of the femur, the narrower intercondylar notch as well as the unfavorable strength ratio of the hamstrings vs. the quadriceps muscle lead to an increased risk for injuries of the anterior cruciate ligament in female soccer.Several studies showed that intervention programs based on neuromuscular or proprioceptive training or intensive strengthening of the hamstrings can reduce the incidence of injuries. Moreover, the importance of sufficient rehabilitation after injuries has to be emphasized, as the reoccurrence of injury is high.

Anterior Cruciate Ligament Injuries↗

PubMed1983

The organization of spontaneous leg movements in newborn infants.

Spontaneous, supine kicking in newborn (2- and 4-week-old) infants is described in terms of its temporal structure, interjoint coordination, and muscle activation characteristics as measured by surface electromyography. Phasic kick movements shoed a constrained temporal organization in the movement, but not the pause phases. Hip, knee, and ankle joints moved in temporal and spatial synchrony, and all three joints showed a rhythmical or periodic organization over time. EMGs revealed antagonist coactivation at the initiation of the flexor movement, but little or not extensor activity. The dorsal muscles, the gastrocnemius and hamstrings, showed less activity than the ventral pair, tibialis anterior and quadriceps. Burst and onset-to-peak durations were also constrained. As a result of neural mechanisms and biomechanical forces, newborn leg movements are structured muscle synergies. This organization has implications both for newborn functioning and for later development.

Journal Article↗

PubMed1999

Effects of muscular fatigue on knee joint laxity and neuromuscular characteristics of male and female athletes.

OBJECTIVE: To elucidate the effects of muscular fatigue on knee joint laxity and the neuromuscular characteristics of male and female athletes. We were particularly interested in determining whether such effects would be more pronounced in female athletes than in males participating in the same sport. DESIGN AND SETTING: Subjects were assessed on 4 dependent variables during a rested and an isokinetically induced muscular fatigue state. We ensured that posttesting measurements were obtained in the fatigued state by testing only 2 dependent variables after each exercise bout. SUBJECTS: We recruited male (n = 17) and female (n = 17) subjects from a population of healthy collegiate basketball and soccer players. MEASUREMENTS: MEASURED DEPENDENT VARIABLES WERE AS FOLLOWS: anterior tibial translation, kinesthesia determined by assessing the threshold to detection of passive motion moving into knee flexion and extension; lower extremity balance ability quantified through a stability index value; and the electromyography-measured muscle activity of 6 knee-stabilizing muscles. RESULTS: In response to muscular fatigue, subjects demonstrated an overall decrease in the ability to detect joint motion moving into the direction of extension, an increase in the onset of contraction time for the medial hamstring and lateral gastrocnemius muscles, and an increase in the first contraction area of the vastus medialis and vastus lateralis muscles. Additionally, the increase in area of the vastus lateralis was greater for the males compared with the females. CONCLUSIONS: Our results suggest that both male and female athletes exhibit decrements in proprioceptive ability and alterations in muscular activity subsequent to muscular fatigue.

Journal Article↗

PubMed1994

Arthrogenic quadriceps inhibition and rehabilitation of patients with extensive traumatic knee injuries.

1. The relationship between joint damage, quadriceps weakness and arthrogenic muscle inhibition was investigated in eight patients who had sustained extensive traumatic knee injury. Isometric and isokinetic quadriceps and hamstring voluntary strength, and quadriceps arthrogenic muscle inhibition during isometric contractions, were measured before and after 4 weeks (approximately 100 h) of intensive rehabilitation. 2. Compared with the uninjured leg, before rehabilitation the injured leg had larger amounts of quadriceps arthrogenic muscle inhibition (P < 0.025), quadriceps (P < 0.0001) and hamstring (P < 0.0001) weakness and severe functional joint instability. There was a negative correlation between the amount of arthrogenic muscle inhibition and quadriceps voluntary contraction force (P < 0.025). 3. After rehabilitation in the injured leg there were small hamstring strength increases (P < 0.05-0.025), but no overall significant quadricep strength increase. Arthrogenic muscle inhibition was statistically unchanged. Severe functional joint instability was still reported by all patients. 4. Previous studies have shown that minimal joint damage evokes relatively less arthrogenic muscle inhibition that does not impede rehabilitation. These data indicate that greater joint damage is associated with greater arthrogenic muscle inhibition, quadriceps weakness and joint instability. Furthermore, intensive rehabilitation had little affect on either quadriceps arthrogenic muscle inhibition or atrophy.

Adult↗

PubMed1991

Physiologic costs of computer-controlled walking in persons with paraplegia using a reciprocating-gait orthosis.

Blood pressure, heart rate, oxygen uptake, cardiac output, and the surface electromyogram from key muscle groups in the upper body were measured in four subjects with paraplegia during ambulation using only a reciprocating-gait orthosis (RGO) and using an RGO with movement assisted by functional electrical stimulation (FES) of the hamstring and gluteus maximus muscles. These data were compared to data collected on four able-bodied control subjects during ambulation at matched speeds. Whether walking with FES and RGOs or walking with RGOs alone, subjects had an optimum gait speed at which efficiency was highest. For paralyzed subjects using FES, the optimum walking speed was approximately 1.5 mph (2.4km/hr); without FES, the optimum speed averaged about 0.75mph (1.2km/hr). Blood pressure, heart rate, oxygen uptake, and cardiac output were measured during ambulation with FES and were found to be higher than those of controls, but they were significantly lower than those in the paralyzed subjects in RGOs with no FES. Electromyogram studies showed that the activity in upper body muscles was much higher when walking in RGOs without FES than in RGOs with FES.

Adult↗

PubMed2006

Joint laxity and isokinetic thigh muscle strength characteristics after anterior cruciate ligament reconstruction: bone patellar tendon bone versus quadrupled hamstring autografts.

OBJECTIVES: To analyze ligamentous stability and isokinetic strength of knee extensor and flexor muscles after anterior cruciate ligament reconstruction using 2 different autografts with identical fixation. DESIGN: This study implements a comparative case series design. SETTING: Schulthess Clinic, Switzerland. PATIENTS: A total of 153 consecutive patients (n = 87 bone-patellar tendon-bone [BPTB]/66 quadruple semitendinosus/gracilis tendons [QSGT] patients) who underwent BPTB and QSGT surgery were functionally assessed. INTERVENTION: All patients were functionally assessed (knee extension/flexion isokinetic strength and knee joint laxity) at a mean follow-up time of 11 months. MAIN OUTCOME MEASUREMENTS: Laxity was measured utilizing the Kneelax arthrometer, whereas isokinetic strength of the knee extensor/flexor muscle groups was measured using the Biodex Multi Joint System 2 (180 degrees/s and 300 degrees/s). RESULTS: The QSGT group had significantly greater knee joint laxity when compared with the BPTB group (P < 0.001). Furthermore, females in the QSGT group demonstrated the greatest knee joint laxity overall (P < 0.001). Additionally, a significant flexor torque deficiency was demonstrated in the QSGT group (P < 0.001); however, no differences in extensor torque were observed. CONCLUSIONS: The use of a BPTB autograft achieved better knee joint stability as well as greater knee flexor torque than the QSGT autograft. Both grafts exhibited a similar knee extensor torque deficit, indicating that only quadriceps strength is not graft-dependent.

Adolescent↗

PubMed1987

Isometric exercise for an individual with hemophilic arthropathy.

Several authors have described nonsurgical rehabilitative techniques for individuals with hemophilia who have single or recurrent hemarthroses. The effects of these low intensity exercise programs are not stated clearly in the literature. In this single-case experimental study, we investigated the effects of a training program of isometric exercise of at least two thirds of maximum voluntary contraction on the knee joint and surrounding muscles of a patient with hemophilia. A 12-year-old subject with severe factor-VIII deficiency and chronic knee arthroses was seen for baseline measurements, three weeks of treatment, and follow-up baseline measurements. The isometric exercise program safely increased right hamstring and quadriceps femoris muscle group strength 40% to 70% without adversely affecting knee range of motion, circumference, or skin temperature and without causing bleeding or discomfort. The use of isometric exercise programs during rehabilitation and maintenance is a promising treatment component for the total care of the individual with hemophilia.

Child↗

PubMed2003

[Relationship between gait speed and strength parameters in multiple sclerosis].

INTRODUCTION: Recent studies have focused on correlation between strength and gait parameters in hemiplegia, suggesting the interest for strength training in patients with central nervous system lesions. The aim of this study was to evaluate this correlation in multiple sclerosis (MS) patients with special regard to the different clinical forms including proprioceptive loss or cerebellar ataxia. PATIENTS AND METHOD: Gait speed and muscular function were performed in 27 patients with moderate affected gait (EDDS < 6). Gait speed was evaluated with Locometre and peak-torques of quadriceps and hamstrings were evaluated with isokinetic dynamometer. Patients were separated in three groups related to their deficiency: spastic group (8 patients), spastic with proprioceptive loss (12 patients) and spastic with cerebellar ataxia (7 patients). Gait parameters were evaluated in 10 healthy subjects as control group. RESULTS: Gait speeds (spontaneous and maximal) and peak torques of quadriceps and hamstring were similar in the three groups. In the whole patients group, gait speed was reduced and related to hamstring peak torque (r = 0.56 at spontaneous speed and 0.51 at high speed) but not with quadriceps peak torque. Patients with proprioceptive loss exhibited not only a higher correlation between gait speed and hamstring torque (r = 0.76 and 0.65 respectively) than other patients but also with quadriceps torque (r = 0.66 and 0.59 respectively) when patients in other groups did not. CONCLUSION: As it was previously pointed out in hemiplegic patients, MS patients exhibit some correlation between gait speed and muscle strength, mainly with hamstrings. These correlations can change in special sensory conditions suggesting that patients with sensory loss use different muscular strategies to maintain gait speed. Strength training may therefore be discussed in MS including specific modalities as a function of clinical parameters.

Biomechanical Phenomena↗

PubMed1984

Physical measurements as risk indicators for low-back trouble over a one-year period.

Of all 30-, 40-, 50-, and 60-year-old inhabitants of Glostrup, a suburb of Copenhagen, 82% (449 men and 479 women) participated in a general health survey, which included a thorough physical examination relating to the lower back. The examination was constituted of anthropometric measurements, flexibility/elasticity measurements of the back and hamstrings, as well as tests for trunk muscle strength and endurance. The reproducibility of the tests was found to be satisfactory. Twelve months after the physical examination 99% of the participants completed a questionnaire sent by mail concerning low back trouble (LBT) in the intervening period. The prognostic value of the physical measurements was evaluated for first-time experience and for recurrence or persistence of LBT by analyses of the separate measurements and discriminant analyses. The main findings were that good isometric endurance of the back muscles may prevent first-time occurrence of LBT in men and that men with hypermobile backs are more liable to contract LBT. Recurrence or persistence of LBT was correlated primarily to the interval since last LBT-episode: the more LBT, the shorter the intervals had been. Weak trunk muscles and reduced flexibility/elasticity of the back and hamstrings were found as residual signs, in particular, among those with recurrence or persistence of LBT in the follow-up year.

Adult↗

PubMed1996

Relationships between running economy and temporal EMG characteristics of bi-articular leg muscles.

Relationships between running economy (RE; submaximal VO(2) for a given running speed) and the temporal EMG characteristics of bi-articular leg muscles were quantified in a group of well-trained runners. Nine subjects completed three test sessions: a determination of maximal aerobic demand (VO(2)max); an accommodation session at the experimental speed of 4.13 m.s(-1) and a session during which EMG and RE data were collected simultaneously at the experimental speed of 4.13 m.s(-1) Measures of muscle onset, on-time durations, and on-time coactivation durations were calculated from the following muscles: rectus femoris, medial hamstrings, lateral hamstrings, and gastrocnemius. Nonparametric correlations between RE and EMG characteristics displayed both positive and negative relationships and exhibited a wide range of values. Two EMG measures were significantly correlated (r > 0.67) with RE. Earlier onset of rectus femoris during swing phase and a shorter duration of hamstring - gastrocnemius coactivation during swing were associated with more economical runners. Although not statistically significant, correlation coefficients calculated for measures of coactivation during stance and RE ranged from -0.42 to -0.65. This trend indicates that individuals who exhibited a greater amount of coactivation between bi-articular muscles during the stance phase of the running cycle tended to be more economical. These relationships suggest different activation patterns in bi-articular muscles between economical and uneconomical runners.

Adult↗

PubMed1998

Musculoskeletal modelling in determining the effect of botulinum toxin on the hamstrings of patients with crouch gait.

This study aimed to determine the effect of hamstring botulinum toxin A (Btx-A) injection in 10 children with crouch gait in terms of changes in muscle length and lower-limb kinematics. Before Btx-A injection limb kinematics were recorded. Maximum hamstring lengths and excursions were calculated by computer modelling of the lower limb. Data were compared with the averaged hamstring lengths of 10 control children. Hamstrings were defined as short if their length was shorter than the average maximum length minus one standard deviation. Gait analysis was repeated 2 weeks after isolated hamstring Btx-A injection. Pre- and postinjection kinematic data and muscle lengths were then compared. Four of 18 injected limbs in three subjects had short medial hamstring before injection, none of the subjects had short lateral hamstrings. Muscle excursion was significantly reduced in the short and adequate maximum muscle length groups. A significant increase in the semimembranosus and semitendinosus length in all of the injected limbs was noted. Only in the short muscle group was a significant increase in muscle excursion observed. Knee extension improved by 13 degrees in the adequate muscle length group and by 15.6 degrees in the short muscle length group. Pelvic tilt and hip flexion increased in both groups non-significantly. Average walking speed postinjection increased from 0.60 ms(-1) to 0.71 ms(-1). Short hamstrings are over-diagnosed in crouch gait. Hamstring Btx-A injection in patients with crouch gait produces significant, repeatable muscle lengthening and improved ambulatory function.

Botulinum Toxins, Type A↗