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PubMed1982

Incidence of Scheuermann's disease. Preliminary report.

This is a report on a study of 96 students aged 17 and 18 at two of our local schools. Each student completed a questionnaire, underwent a simple examination of the spine and a measurement of the passive stretch in the hamstring muscles, and had a lateral X-ray of the dorsal and upper lumbar spine. An overall X-ray evidence of Scheuermann's Disease was detected in 60% of males and 23% of females. The possible significance of these results is discussed.

Adolescent↗

PubMed1982

[Serous ischial bursa].

The ischial bursa (Bursa ischiatica) lies on the posterior aspect of the tuberosity of the ischium at the level of the origin of the hamstring muscles. Its relations with the inferior fibers of the musculus gluteus maximus vary with the degree of the hip's flexion. Its role in the sitting position explains the specific bursitis when medullar lesions disturb the normal physiology of this posture.

Hip Joint↗

PubMed1982

"Hüftlendenstrecksteife"--a report of 100 cases.

Hüftlendenstrecksteife (HLS) is not a clinical entity, but a symptom-complex which can be produced by many diseases both inside and outside the spinal canal. Its clinical characteristics are: a) the wooden board sign, b) fixed lumbar lordosis, c) the special shifting gait. The etiology of HLS reported here was mostly (96%) HNP. Irritation of the lower lumbar nerves ensures spasms and/or contracture of the lumbar and hamstring muscles. Lumbogluteal soft tissue strain (30% of all cases) may also produce the pathologic conditions of the lumbosacral muscles. One hundred cases of HLS were treated in our hospital and the method of treatment and its results are discussed.

Female↗

PubMed1980

Dynamic motor capacity in spastic paresis and its relation to prime mover dysfunction, spastic reflexes and antagonist co-activation.

Dynamic motor capacity was studied in 24 patients with spastic paraparesis (18 cases) or hemiparesis (6 cases). Torque was recorded with an isokinetic dynamometer in voluntary dynamic knee extensions and flexions at maximum effort and in passive movements at preset speeds of 30, 90 and 180 deg . s-1. EMG was recorded with surface electrodes from the quadriceps and the hamstring muscles. The capacity to accelerate motion up to preset speed was deficient in all patients as compared with healthy subjects. The moment of muscle force in movements at maximum effort was generally more reduced in fast than in slow movements. Spastic restraint in passive movements was low in the great majority of legs examined except in the fastest flexion, where about half showed restraint greater than 10 Nm. In a few cases, spastic reflexes were inhibited in voluntary motion. Most commonly, the restraint was greater in voluntary than in passive movements at equal range and speed. In voluntary motion, antagonist restraint was more common at high than at low speed of motion, and when present at low speed, it usually became greater with increasing speed of motion. It often reached a considerable magnitude, as estimated from EMG and may constitute a crucial component in the motor handicap.

Adult↗

PubMed1981

Relationships between tibial rotary torque and knee flexion/extension after tendon transplant surgery.

The hamstring muscles play an important role in decelerating and checking tibial rotation before excessive stresses are applied to knee support structures. The purpose of this study was to determine the relationships between standard flexion/extension rehabilitative techniques and tibial rotary torque among subjects who had received pes anserinus transfers at least 1 year prior. Postsurgical and healthy contralateral limbs of 15 males were tested for maximum, isokinetic knee flexion/extension and internal/external tibial rotation. An adjustable chair and stabilizing boot were used to minimize extraneous hip, thigh and subtalar movements. Product-moment correlation coefficients were computed to determine the relationships between muscle forces generated during tibial rotation and knee flexion/extension. Relatively small relationships were found between rotation and flexion. Tibial rotation and flexion were more highly correlated in the nonsurgical than in the surgical limbs. The results also revealed that peak torque was generated within the first 5-10 degrees of motion for tibial rotation and within the first 20-30 degrees of motion for knee flexion and extension. The data indicate that measures of maximal knee flexor torque cannot be used to predict the rotational capabilities of the same muscle group and that separate measurement and rehabilitative techniques are necessary. Further analyses of postsurgical knees revealed force deficits among knee flexors and extensors when compared to nonsurgical counterparts. The findings suggest long-term sensitivity of the quadriceps to immobility.

Adolescent↗

PubMed1995

Sensitivity of osteoinductive activity of demineralized and defatted rat femur to temperature and duration of heating.

For autogenous and allogeneic bone grafts, heat treatment has been thought to kill malignant cells and viruses such as human immunodeficiency virus. It is unclear whether heat treatment could preserve bone-inductive activity. Cortical bones from 6-week-old rat femurs were heated in a water bath at a temperature of 50 degrees-100 degrees C for periods of 15 minutes to 10 hours. After treatment, they were defatted and decalcified. Each sample was transplanted into the hamstring muscle of 3-week-old rats. Eleven days after transplantation, the samples were removed and messenger ribonucleic acids (mRNAs) were determined for alkaline phosphatase and collagens in the transplant. Twenty-one days after transplantation, actual bone formation was studied by histologic analysis and measurement of calcium content. Heat treatment at 60 degrees C for 10 hours and at 70 degrees C for 1 hour preserved bone-inductive activity, as indicated by the induction of mRNAs for alkaline phosphatase and Type I and Type II collagens. Significant decreased in Type II collagen mRNA and calcium content were observed at 70 degrees C when the transplants were heated for 10 hours, suggesting the importance of evaluating the duration of heat treatment.

Alkaline Phosphatase↗

PubMed1995

[A case of localized hypertrophic neuropathy in the sciatic nerve].

A 26-year-old male patient gradually developed muscular atrophy of the right lower leg over a two-year period. Neurological examination revealed absent Achilles tendon reflex and muscular atrophy of the right lower leg and right hamstring muscles. Conduction velocity of the F waves was delayed in the right posterior tibial nerve. A computerized tomography scan and magnetic resonance imaging revealed a mass lesion along the proximal segment of the right sciatic nerve. Exploration revealed a fusiformly swollen sciatic nerve. Histological examination showed that a swollen segment of the sciatic nerve was filled with onion-bulb formations of perineurial cells, consistent with the diagnosis of localized hypertrophic neuropathy. This condition should be added to several etiologies of monomelic amyotrophy. Electrophysiological studies and neuroimaging techniques were useful in obtaining differential diagnosis.

Adult↗

PubMed1994

Rising and sitting down in stroke patients. Auditory feedback and dynamic strength training to enhance symmetrical body weight distribution.

The purpose was to study vertical ground reaction force feedback and dynamic knee extensor training used to enhance stroke patients' symmetrical body weight distribution while rising and sitting down. Sixteen healthy subjects and 51 stroke patients participated in the studies. Two vertical strain gauge force transducers attached to two force-measuring platforms were used to measure body weight distribution over the lower limbs. An auditory feedback device, specially developed for training body weight distribution on the paretic leg, employed two electronic balances sensing vertical forces from each foot, separately. Torque of maximal voluntary eccentric and concentric knee extensor and flexor actions at 30, 60, 120, 180 and 240 deg/s was recorded with an isokinetic dynamometer together with surface electrodes from the quadriceps and hamstring muscles. When instructed to rise with even body weight on each lower limb, the stroke patients loaded the paretic leg more than when rising habitually, indicating that stroke patients have a latent motor capacity. Stroke patients' own estimations on visual analogue scales of body weight distributed on the paretic leg correlated with measured loading of the paretic leg in rising. After six weeks of training with auditory feedback of vertical ground reaction forces in the acute phase after stroke, the patients improved their loading of the paretic leg compared to a control group. The patients distributed body weight over the lower limbs nearly symmetrically while rising and while sitting down. The peak torque was not greater, however, than in the control group, rising with an asymmetrical body weight distribution. This implies that the patients after feedback training were better at using the knee extensor torque of the paretic leg to attain symmetrical body weight distribution over the lower extremities. Changes in improvement of physical performance and sitting to standing were greater than in the control group. No differences between groups were seen in performance of activities of daily living. Body weight distribution over the limbs in rising and in sitting down was re-tested on average 33 months after end of training. The symmetrical weight distribution after feedback training was not maintained over time. Knee extensor strength improved after six weeks of eccentric and concentric training, starting on average 27 months after stroke. The increase in strength was related to enhanced activation of agonist EMG activity. Eccentric training seems to be superior to concentric training with reference to a) improved body weight distribution over the lower limbs in rising, to b) increased knee extension torque and to c) increased agonist EMG activity without a concomitant, augmented EMG activity of the antagonistic knee flexor muscles. It was concluded that stroke patients have a latent motor capacity, that six weeks auditory feedback training promotes symmetrical body weight distribution which, however, is not consistent over time and that isokinetic eccentric training is superior to concentric training with reference to weight distribution in rising, knee extension torque and EMG activity.

Adult↗

PubMed1977

Prolongation of survival of rat parathyroid allografts by enhancing serum and tissue culture.

To determine whether survival of allografted rat parathyroid tissue could be enhanced either by the administration of antidonor serum (enhancing serum) or by tissue culture of the graft, parathyroids from Lewis x Brown Norway F1 (LBNF1) rats were transplanted beneath the fascia and between hamstring muscle fibers of hypocalcemic parathyroidectomized Lewis recipients (serum calcium 4.3 +/- 0.13mg%--mean +/- SEM). A drop in serum calcium below 7.5 mg% indicated rejection. Seven group 1 rats that received isogeneic parathyroids recovered from their hypocalcemic state and remained normocalcemic indefinitely. Seven group 2 rats that received LBNF(1) parathyroids experienced a reduced mean maximal response (MMR) of calcium increase of 4.1 +/- 0.2 mg% and the grafts had a median survival time (MST) of 16.0 +/- 1.32 days. Group 3 rats that received 1 ml of enhancing serum by intraperiotoneal injection, cytotoxic titer 1:128, on alternate days for five doses experienced an MMR of 5.0 +/- 0.7 mg% and had an MST of 19.3 +/- 1.07 days. When enhancing serum, cytotoxic titer 1:256, was administered to group 4, the MST of the grafts was increased to 29.7 +/- 1.19 days. When LBNF(1) parathyroid tissue was preserved in tissue culture for 14 to 21 days and then transplanted into Lewis recipients, the MST was 22.5 +/- 1.48 days. The administration of enhancing serum to recipients of cultured parathyroids further extended graft survival, MST 57.5 +/- 2.32 days. In summary, survival of allografted parathyroid tissue can be prolonged by the administration of enchancing serum or tissue culture of the graft. When enhancing serum was administered to recipients of cultured allografted parathyroid tissue, survival was further increased.

Animals↗

PubMed1997

Co-activation of the hamstrings and quadriceps during the lunge exercise.

The anterior lunge exercise is a closed chain kinetic exercise that has been developed to improve the function of the lower limb and to strengthen the hamstrings and quadriceps, simultaneously. In this study, a three-dimensional biomechanical analysis of this exercise was conducted in order to understand the mechanics of this rehabilitation activity. Experimental conditions were recorded using an active optoelectronic kinematic data capture system (OPTOTRAK), two force plates (AMTI) and electromyography (EMG). Data were collected from healthy male subjects while performing several lunges. When the distance between the toe of the rear leg and the heel of the front leg (lunging distance) was maximum, a large net flexion moment was predicted in the front leg in the extented position. This moment was reversed to a large net extension moment in the flexed position. A large increase in the net extension moment in the rear leg was also predicted as the front knee was bent from 5 degrees to 90 degrees of flexion. These data suggest that quadriceps and hamstring muscles co-contraction occur during a maximum lunge in the front leg when it is in the flexed position.

Biomechanical Phenomena↗

PubMed1998

Quantification of cocontraction in spastic cerebral palsy.

Antagonist cocontraction was hypothesized to limit net moment production in children with spastic diplegic cerebral palsy (CP). A second hypothesis was that concontraction would vary with joint angle. To test these hypotheses, surface EMG activity and moment data from the quadriceps and hamstrings muscle groups were obtained from children with CP and compared with normally developing children during isometric flexion and extension exertions. A biomechanical model was developed to predict individual moments produced by the agonist and antagonist muscle groups. Concontraction was defined as the percentage of the net moment that was negated by the antagonist moment. The model performed well in predicting the measured moment as illustrated by high R2 correlation coefficients and low prediction errors. The mean maximum moment produced was greater in normally developing children than children with CP in both flexion and extension. Antagonist cocontraction during extension was greater in children with CP (12.2 +/- 14.4%) than in normally developing children (4.9 +/- 3.8%), implying that antagonist cocontraction is one explanation for the observed extension weakness in children with CP. However, during flexion, cocontraction was not significantly different between the two groups. Cocontraction differed significantly with joint angle in both groups during flexion and in the normally developing children during extension. Although quantifying coactivation based on EMG activity alone produced similar results, it underestimated the effect of the antagonist. The quantification of cocontraction has potential applications for characterizing spastic muscle dysfunction and thereby improving clinical outcomes in children with CP.

Adolescent↗

PubMed2004

Functional assessment after acute and chronic complete ruptures of the proximal hamstring tendons.

Nonoperative treatment of acute or chronic complete ruptures of the proximal hamstring tendons leads to functional impairment in sports activities. The objective of the study was to evaluate the functional status after primary and delayed surgical treatment including objective (isokinetic hamstring and quadriceps muscle testing, hamstring flexibility) and subjective parameters (overall satisfaction, postoperative sports level). A total of eight patients (six male, two female) with an average age of 40.0 years (range 23-60) were treated operatively by refixation of the ruptured tendons in anatomical position using a suture anchor system. Six patients were treated within 3 weeks after trauma, while two patients were operated after delayed diagnosis of more than 2 months. The average clinical follow-up was 33.3 months (range 12-59). Overall, at minimum follow-up of 20 months, all patients were satisfied with the functional outcome and would undergo operative treatment again. At follow-up, seven patients could return to their preinjury sports level. In two patients, however, we noticed a delayed return to preinjury sports level of more than 24 months. The peak torque of the operated hamstrings in isokinetic muscle testing was 88.3% (range 62.9-113.8), as compared to the contralateral extremity. The ratio of hamstring to quadriceps muscle strength was on average 0.55 (range 0.44-0.66; injured side) versus 0.61 (range 0.52-0.68; uninjured side). Measurement of hamstring flexibility showed no difference to the contralateral hamstrings. In cases of timely diagnosis, surgical treatment is the standard treatment for complete ruptures of the proximal hamstring tendons in patients with ambitions inclined toward sports. The suture anchor system implements an elegant and effective technique for the treatment of such lesions.

Acute Disease↗

PubMed1997

Lengths of hamstrings and psoas muscles during crouch gait: effects of femoral anteversion.

Recent studies of muscle lengths measured by means of gait analysis data and musculoskeletal models have suggested that in many cases of crouch gait in patients with cerebral palsy, the hamstrings are of normal length and the psoas muscles are short. In these studies, however muscle lengths were calculated by applying kinematic data from a child's joint to a normal adult model. Children with cerebral palsy and other disorders generally do not have normal bone architecture but instead have muscle attachment points and muscle paths altered by osseous deformities. In this study, we explored the consequences of using normal adult musculoskeletal models to calculate hamstring and psoas lengths for children with cerebral palsy. Specifically, for a group of subjects with cerebral palsy who walk with a crouch gait, we investigated the changes in muscle lengths that arise when a patient-specific representation of clinically measured femoral anteversion was added to a model of normal musculoskeletal geometry. The calculation of psoas muscle length was found to be very sensitive to femoral anteversion whereas the calculation of hamstrings length was found to be relatively insensitive to this osseous deformity.

Adolescent↗

PubMed2004

Influence of hamstring lengthening on muscle activation timing.

The purpose of this study was to describe the changes in muscle activation patterns using surface electromyography (sEMG) during walking in patients with cerebral palsy (CP), before and after hamstring lengthening. In the current clinical use of sEMG during walking in CP for pre-operative planning, various authors have observed that timing of muscle activation patterns hardly changes after surgical intervention. This observation is based on tendon transfer studies and visual interpretation of raw EMG signals. Little is known about the effect of muscle lengthening on muscle activation patterns of the lengthened muscles and their antagonists. Fifteen children with CP comprising a total of 23 hamstring lengthenings were included in this study. Surface EMG of semitendinosus and vastus lateralis was measured before and after surgery. Timing parameters of the sEMG patterns were quantified, using an objective burst detection algorithm and statistically evaluated. Results showed that hamstring lengthening causes statistically significant differences in timing of both the semitendinosus and vastus lateralis. It is concluded that timing parameters of operated muscles and their antagonists after surgery do change. The delayed off-time of the semitendinosus and the decreased burst duration of the antagonist (the vastus lateralis) after surgery were the most important changes.

Adolescent↗

PubMed2003

Effects of moist heat on hamstring flexibility and muscle temperature.

The purpose of this study was to determine whether the application of a moist heat pack (MHP) could increase hamstring flexibility. Both legs for each subject were used for this study. Each leg was randomly assigned to either an MHP leg or a control leg condition. Twenty-seven male subjects (height = 178.5 +/- 8.6 cm; weight = 84.4 +/- 18.7 kg; age = 21.9 +/- 6.3 years) volunteered for this study. For the MHP leg condition, baseline hamstring flexibility was measured using an active knee extension test. A 23-ga indwelling thermistor was inserted to a depth of 2.54 cm to measure hamstring temperature. After baseline temperature was recorded, 2 MHPs were placed on either side of the thermistor until temperature was increased by 0.4 degrees C. Hamstring flexibility postintervention measurements were performed at 0, 4, 8, and 16 minutes. The same protocol was used for the control leg, without the MHP application. A 2 x 5 repeated-measures analysis of variance revealed no significant interaction between the MHP and the control leg condition. These results support previous findings that MHP application does not significantly affect muscle flexibility. After application of an MHP, it takes 20-25 minutes to increase intramuscular temperatures by 0.4 degrees C. Both of these findings should be taken into consideration when using an MHP to increase muscle flexibility.

Adolescent↗

PubMed1988

Tightness of hamstring- and psoas major muscles. A prospective study of back pain in young men during their military service.

Muscular tightness and the therapeutic effect of stretching has been widely discussed during the last few years in sports training and physiotherapy. Within a prospective study of back function and pain before and after compulsory military service, tightness of hamstring- and psoas muscles was assessed. Around 600 young men were examined three times over a period of four years. Tight hamstring muscles were found to be very common in this group. Only 43% of the right and 35% of the left legs reached an angle of at least 80 degrees from the couch during the straight-leg-raising test (Lasegue's test). The test of muscular tightness showed a significant test-retest reliability over all examinations. Tight hamstring- or psoas muscles could not be shown to correlate to current back pain or to the incidence of back pain during the follow-up period.

Adolescent↗

PubMed1991

Maximal peak torque as a predictor of angle-specific torques of hamstring and quadriceps muscles in man.

This study assessed the relationship between the isokinetic peak torque (PT) (speed of movement 1.05 and 3.14 rads-1) and the angle-specific torques (ASTs) at 0.26 and 1.31 rad of knee flexion in multiple contractions of the quadriceps and hamstrings in 70 individuals with a chronic anterior cruciate ligament (ACL) insufficiency and 78 individuals with a chronic medial collateral ligament (MCL) insufficiency in one knee. At every test speed, the Pearson product moment correlation coefficients (r) between the PT and ASTs were highly significant (P less than 0.001) in the uninjured knees (r = 0.61-0.93) as well as in the knees with ACL (r = 0.61-0.87) and MCL (r = 0.74-0.91) insufficiency. In addition, in both groups the majority of the correlation coefficients exceeded 0.80, which is generally regarded as the threshold for the relationship to be considered clinically significant. Furthermore, using regression analysis, both extremities showed completely non-systematic distribution of the residuals. It is concluded that in healthy knees or knees with ACL or MCL insufficiency, the predictability of ASTs from PT was good, and, therefore, that AST analyses may offer little additional information about thigh muscle function to that obtained from a simpler and more commonly used measurement, the PT analysis.

Adult↗

PubMed1993

[Incidence of short hamstrings and leg muscles at ages 3-17 years].

In 1991, 769 children and adolescents, 98% of the pupils in the various age groups in seven schools and ten kindergartens on Funen, were examined. Seventy-five percent of the boys and 35% of the girls over the age of ten proved to have such short hamstrings that one knee had a extension deficit without violence of > or = 40 degrees when the hip was flexed 90 degrees. More than 10% of the boys over the age of ten had an extension deficit of > or = 60 degrees. Forty-five children had a difference > or = 15 degrees between the two legs. The triceps surae muscles are too short if the corrected foot can only be pressed slowly to the right angle. This was found to be the case for 25-64% of the children from the age of three to 17. Therefore, we must conclude that it is necessary to allow time in kindergarten and school for the children to stretch their muscles a few minutes daily.

Adolescent↗