PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Muscle Stretching Exercises”

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 109 records · Page 6Linked to original sources
PubMed1997

Viscoelastic behavior of plantar flexor muscle-tendon unit at rest.

Muscle stretching as an exercise routine is widely used in orthopaedic and neurological rehabilitation. However, the muscle response to specific stretching parameters is still unclear. The aim of this study was to investigate the effect parameters, such as stretch velocity, stretch extent, and initial muscle-tendon resistance, on the plantar flexor response to passive movement. Eighteen healthy subjects (23-41 years) participated in this study. Five passive ankle dorsiflexions were randomly imposed at various velocities from 5 degrees/sec to 180 degrees/sec using a Kin-Com dynamometer, while unwanted activations of the soleus and tibialis anterior muscles were detected with surface electrodes. The resistive torque was averaged at -10 degrees and 0 degree of dorsiflexion. As shown by analyses of variance followed by Scheffé post hoc procedures, the resistive torque was significantly increased (p < 0.01) between 5 degrees/sec and higher velocities (60 degrees/sec or 120 degrees/sec and higher). A strong linear resistive torque-velocity relationship was also observed, as indicated by Pearson correlation coefficients of 0.92 (-10 degrees) and 0.91 (0 degree). The absolute resistive torque increment, calculated at 180 degrees/sec, was larger at 0 degree of dorsiflexion than at the -10 degrees of dorsiflexion position. Finally, subjects with larger initial plantar flexor resistance had a higher resistive torque increment (p < 0.05) at a high velocity of stretch (180 degrees/sec) than those with less initial muscle-tendon resistance. These results indicate that 1) the nonreflex resistive torque response to stretch is velocity-sensitive and 2) both a larger stretch extent and muscle initial resistance lead to greater resistive torque increments at high velocity. These observations suggest that slow and gradual stretching procedures, rather than rapid or ballistic movements, should be used, especially with stiff muscles to reduce the chance of injury from excessively high tension.

Adult↗
PubMed1993

Skeletal muscle fiber hyperplasia.

Skeletal muscle enlargement in adult animals has been ascribed primarily to changes in fiber cross-sectional area (i.e., fiber hypertrophy); however, recent evidence from several laboratories suggests strongly that fiber hyperplasia contributes to muscle mass increases in adult animals and possibly human athletes. Scientists have used three models to study the cellular mechanisms of muscle enlargement: compensatory hypertrophy, stretch, and exercise. Each of these models has provided direct as well as indirect evidence supporting the occurrence of muscle fiber hyperplasia. Direct counts of muscle fibers using nitric acid digestion techniques have shown that both exercise and stretch overload result in significant increases (range = 9-52%) in fiber number. Indirect fiber counts using histological cross-sections have suggested fiber hyperplasia (range = 10-82%) in all three models. Additionally, the expression of embryonic myosin isoforms have provided indirect evidence for new fiber formation in stretch overloaded muscle. Furthermore, satellite cells have been shown to be involved in muscle fiber hyperplasia in stretch and exercise.

Animals↗
PubMed2006

Therapeutic effect of passive mobilization exercise on improvement of muscle regeneration and prevention of fibrosis after laceration injury of rat.

OBJECTIVE: To evaluate the muscle healing effect of passive mobilization exercises after a laceration injury. DESIGN: Randomized controlled trial. SETTING: Basic science laboratory. ANIMALS: Male Sprague-Dawley rats (N=36), age ranging from 8 to 10 weeks and weight ranging from 300 to 400 g. INTERVENTION: The bilateral gastrocnemius muscles were lacerated. The left leg muscles were used as the study groups and the right side was used as the control (lacerated muscles without any treatment, n=8). In the exercise group (n=24), passive mobilization exercise (15 min/d) was performed for 5 days starting from different time points (2, 7, and 14d postlaceration). The decorin group (n=8) was injected with decorin (50 microg at 14d postlaceration), which is a well-known antifibrotic agent. Four animals were used as the normal controls, in which only the muscle strength was evaluated. All the animals were killed 4 weeks after the laceration. MAIN OUTCOME MEASURES: The histologic characterization of muscle regeneration (hematoxylin and eosin staining, number and diameter of the centronucleated, regenerating myofibers), muscle fibrosis (vimentin-positive area, Masson modified trichrome staining positive area), and muscle strength (analysis of fast twitch strength). RESULTS: The level of fibrosis was more than 50% lower in the exercise and decorin groups than in the control (P<.05). The decorin group showed the highest number of regenerated, new myofibers and the highest muscle strength. All of the exercise groups, regardless of the starting time of exercise, also showed significant improvement in regeneration and strength. However, the exercise group starting 14 days after the laceration showed the best results. CONCLUSIONS: Stretching exercises after a muscle laceration injury has a strong antifibrotic effect, as much as a well-known antifibrotic agent, decorin. According to the results, the best time to begin stretching exercises is 14 days after laceration for antifibrosis and muscle regeneration.

Analysis of Variance↗
PubMed2006

Incidence, risk, and prevention of hamstring muscle injuries in professional rugby union.

BACKGROUND: The incidence of hamstring muscle injuries in professional rugby union is high, but evidence-based information on risk factors and injury-prevention strategies in this sport is limited. PURPOSE: To define the incidence, severity, and risk factors associated with hamstring muscle injuries in professional rugby union and to determine whether the use of hamstring strengthening and stretching exercises reduces the incidence and severity of these injuries. STUDY DESIGN: Cohort study (prevention); Level of evidence, 3. METHODS: Team clinicians reported all hamstring muscle injuries on a weekly basis and provided details of the location, diagnosis, severity, and mechanism of each injury; loss of time from training and match play was used as the definition of an injury. Players' match and training exposures were recorded on a weekly basis. RESULTS: The incidence of hamstring muscle injuries was 0.27 per 1000 player training hours and 5.6 per 1000 player match hours. Injuries, on average, resulted in 17 days of lost time, with recurrent injuries (23%) significantly more severe (25 days lost) than new injuries (14 days lost). Second-row forwards sustained the fewest (2.4 injuries/1000 player hours) and the least severe (7 days lost) match injuries. Running activities accounted for 68% of hamstring muscle injuries, but injuries resulting from kicking were the most severe (36 days lost). Players undertaking Nordic hamstring exercises in addition to conventional stretching and strengthening exercises had lower incidences and severities of injury during training and competition. CONCLUSION: The Nordic hamstring strengthening exercise may reduce the incidence and severity of hamstring muscle injuries sustained during training and competition.

Adult↗
PubMed1994

Stretching exercises: effect on passive extensibility and stiffness in short hamstrings of healthy subjects.

Passive muscle stretch tests are common practice in physical therapy and rehabilitation medicine. However, the effects of stretching exercises are not well known. With an instrumental straight-leg-raising set-up the extensibility, stiffness, and electromyographic activity of the hamstring muscles have been experimentally determined and the effects of stretching exercises have been evaluated. Fourteen volunteers, aged 20 to 38 years (mean 27.3) were selected from a young healthy population with the toe-touch test (finger-ground distance greater than 0cm), and a straight-leg-raising angle about 80 degrees. According to usual standards the diagnosis was short hamstrings. One group of seven subjects was treated during 4 weeks with a daily home exercise program aimed at stretching the hamstrings, whereas the untreated group was used as a control. Instrumental straight-leg-raising was performed in the subjects of both groups. The significance of the differences between the mean values was determined with the Student's t-test. Comparison of the data obtained before and after the muscle stretching program showed a slight but significant increase in the extensibility of the hamstrings accompanied with a significant increase of the stretching moment tolerated by the passive hamstring muscles. However, the elasticity remained the same. It is concluded that stretching exercises do not make short hamstrings any longer or less stiff, but only influence the stretch tolerance.

Adult↗
PubMed1991

Neuromuscular control of the human leg extensor muscles in jump exercises under various stretch-load conditions.

Ten active males performed reactive drop jumps from a height of 40 cm in six experimental conditions: jumps with additional loads of 100 N (BW + 100 N) and 200 N (BW + 200 N), an ordinary jump with body weight (BW) and three jumps in which the body weight was artificially reduced (BW-172 N, BW-337 N and BW-495 N). The vertical ground reaction forces, the angular displacement in the knee and ankle joints as well as the surface electromyogram (EMGs) of the triceps surae muscles and tibialis ant. muscle were recorded. When compared to the control condition (BW) in the jumps with extra load and in the jumps with reduced body weight, both the take-off velocity as well as the mean vertical ground reaction force were decreased during the push-off phase. The integrated EMG before ground contact as well as the duration of the preactivation phase was significantly reduced as a function of the load condition. Upon the touchdown, the coactivation of the muscles acting around the ankle joint was greatest in the control jump. Through all experimental conditions, the mean activation amplitude remained rather constant both for the impact as well as for the push-off phase of the contact. It is concluded that the centrally programmed activity prior to the contact can be seen as the decisive mechanism in the regulation of the stiffness behavior of the tendomuscular system. The extent of the preprogrammed activity determines mainly the physical output of the entire jump exercise.

Adult↗
PubMed1987

Fatigue during stretch-shortening cycle exercises: changes in mechanical performance of human skeletal muscle.

Stretch-shortening cycle (SSC), which is a normal contraction behavior of muscle, was used as a model to investigate muscular fatigue. Nine male volunteers were subjected to 100 repeated and exhaustive SSC contractions of the forearm extensors using a special sledge apparatus incorporating a force plate system. The fatigue contractions were performed on submaximal levels but the before-after comparison also included maximal drop-jump condition on the sledge as well as falls on to the floor. The results indicated that in the 100 submaximal SSCs the fatigue was characterized by increases in the contact times for both the eccentric and concentric phases of SSC, but the influence was more pronounced on the concentric part. The force-time curves during contact on the platform were influenced by fatigue so that the initial force peak became higher and the subsequent initial drop of force more pronounced. During submaximal and maximal drops, the angular velocities changed in the two phases of SSC. With progressing fatigue, the eccentric maximal angular velocity increased and the corresponding concentric velocities decreased. These changes were accompanied by slight changes in the elbow joint mechanism with respect to the contact, release, and maximal flexion angles. The results suggest that repeated SSC induces fatigue and the fatigue effects on the mechanical behavior of the muscle are very much similar to those induced by either isometric or concentric fatigue contractions. However, the transfer of the energy between eccentric and concentric phases was drastically reduced and this implies that SSCs can be used effectively to examine the fatiguability of the system regulating muscle stiffness during exercise.

Adult↗
PubMed1986

Electromyographic and force production characteristics of leg extensor muscles of elite weight lifters during isometric, concentric, and various stretch-shortening cycle exercises.

Electromyographic and force production characteristics of leg extensor muscles of elite weight lifters (n = 14) were examined during isometric, concentric, and various stretch-shortening cycle exercises. The data showed that utilization of stored elastic energy of leg extensor muscles was observable in countermovement jumping (CMJ) conditions performed at various loads. These greater (P less than 0.01-0.001) vertical jumping heights obtained in CMJ conditions in comparison to the respective squat jumps (SJ) took place at all loads examined from 0 up to 180 kg with no differences in the average IEMG activity between the concentric phases of the performances. In various dropping jumps (from 20 to 100 cm), the average jumping heights were not, however, greater than in the squat jump. The jumping heights both in SJ and CMJ correlated negatively (r = -0.56 and -0.58; P less than 0.05) with the time of isometric force production. Maximal isometric force correlated (r = 0.61; P less than 0.01) with the thigh girth but not (r = 0.22; NS) with the mean muscle fiber area of the vastus lateralis muscle. The jumping heights in SJ and CMJ performed with higher (100-140 kg) loads correlated more significantly (r = 0.76-0.79; P less than 0.01-0.001) than that of maximal isometric force (r = 0.47-0.67; P less than 0.05-0.01) with the results in the Olympic weight lifting. The present findings indicate the important role of effective recoil of the elastic energy in the muscle during the stretch-shortening cycle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphatases↗
PubMed1984

Muscular hypertrophy after chronic radiculopathy.

In four patients, calf muscular hypertrophy developed after the onset of sciatica. Hypertrophic muscles were weak and showed electromyographic signs of denervation. In all cases, calf muscle biopsy showed striking hypertrophy of type 1 and, especially, type 2 muscle fibers. This hypertrophy was associated with other signs indicating a neurogenic lesion. Muscle hypertrophy is a rare finding in neurogenic lesions. Stretch and exercise of muscle are probably the causative factors.

Adult↗
PubMed1993

Evaluation of soft foot orthotics in the treatment of patellofemoral pain syndrome.

BACKGROUND AND PURPOSE: The effectiveness of soft foot orthotics in the treatment of patients who have patellofemoral pain syndrome was investigated. SUBJECTS: Subjects were 20 adolescent female patients, aged 13 to 17 years (mean = 14.8, SD = 1.2), who were diagnosed with patellofemoral pain syndrome and who exhibited excessive forefoot varus or calcaneal valgus. METHODS: Subjects were randomly assigned to one of two groups: a control group (n = 10), which took part in an exercise program, or a treatment group (n = 10), which used soft foot orthotics in addition to participating in the exercise program. The exercise program consisted of quadriceps femoris and hamstring muscle strengthening and stretching exercises. A visual analogue scale was used to assess the level of pain of the subjects over an 8-week period. RESULTS: Both the treatment and control groups demonstrated a significant decrease in the level of pain, but the improvement of the treatment group was significantly greater than that of the control group. CONCLUSION AND DISCUSSION: The results suggest that in addition to an exercise program, the use of soft foot orthotics is an effective means of treatment for the patient with patellofemoral pain syndrome.

Activities of Daily Living↗
PubMed1996

Lumbar lordosis and pelvic inclination of asymptomatic adults.

BACKGROUND AND PURPOSE: We examined the association between pelvic inclination and lumbar lordosis during relaxed standing and eight variables thought to contribute to lordosis. SUBJECTS: Ninety subjects (45 men, 45 women) without back pain or a history of surgery were examined. The mean age was 54.8 years (SD = 8.5) for male subjects and 58.9 years (SD = 8.8) for female subjects. METHODS: Multiple linear regression modeling was used to assess the association of pelvic inclination and size of lumbar lordosis in a standing position with age, gender, body mass index, physical activity level, back and one-joint hip flexor muscle length, and performance and length of abdominal muscles. RESULTS: Abdominal muscle performance was associated with angle of pelvic inclination for women (R2 = .23), but not for men. Standing lumbar lordosis was associated with abdominal muscle length in women (R2 = .40), but it was multivariately associated with length of abdominal and one-joint hip flexor muscles and physical activity level in men (R2 = .38). No correlation was found between angle of pelvic inclination and depth of lumbar lordosis in a standing position. CONCLUSION AND DISCUSSION: Neither univariate nor multivariate regression models account for variability in the angle of pelvic inclination or size of lumbar lordosis in adults during upright stance; no correlation was found in standing between these two variables. The use of abdominal muscle strengthening exercises or stretching exercises of the back and one-joint hip flexor muscles to correct faulty standing posture should be questioned.

Abdominal Muscles↗
PubMed1986

The effect of fatigue on store and re-use of elastic energy in slow and fast types of human skeletal muscle.

Stretch-shortening exercises are characterized by enhancement of performance when compared to the work output performed in shortening conditions. There is evidence that fast subjects are unable to re-use great amounts of elastic energy during stretch-shortening cycles performed with slow stretching speed and large stretching length. In the present study, 14 subjects possessing different fibre types in m. vastus lateralis performed vertical jumps with and without preliminary countermovement and with large angular displacement and slow stretching speed The jumping tests were executed before and immediately after fatigue induced by short intense exercises (60 s of continuous rebound jumping). The results indicated that the percentage of re-use of elastic energy was more pronounced in slow subjects compared to fast ones during the test performed before fatigue (28.3% vs. 22.8%). In contrast fast subjects demonstrated a greater percentage re-use of elastic energy than slow ones after fatigue (32% vs. 22.5%). Similarly, the negative relationship observed before fatigue, between the percentage of re-use of elastic energy and percentage of fast twitch fibres (r = 0.50, n = 14, P less than 0.05), was reversed after fatigue (r = 0.55, n = 14, P less than 0.05). The results can be interpreted through differences in sarcomere cross-bridges life-times between fast and slow twitch muscle fibres. The slow twitch-type muscle fibre may be able to retain the cross-bridge attachment for a longer period of time during no fatigued conditions, and therefore it may utilize elastic energy better in slow type ballistic motion. On the other hand, fast twitch type muscle fibres are more affected by fatigue, which might have induced a remarkable decrease of the cross-bridge attachment detachment cycle. Decrease of the cross-bridge rate cycle might allow fast twitch-type muscle fibres to retain longer the elastic energy stored during the stretching phase and then re-use it during positive phase.

Adult↗
PubMed1998

Interaction between muscle stiffness and stretch reflex sensitivity after long-term stretch-shortening cycle exercise.

The short latency stretch-reflex component (M1) and its interactions with muscle stiffness and with muscle performance were investigated before and after long-term stretch-shortening cycle (SSC) exercise. Dramatic fatigue induced reduction in maximal SSC performance capability, and electromyographic activity was accompanied by a consistent decrease in the M1 reflex component and eccentric peak stiffness of the muscle. It can be suggested, therefore, that the decreased muscle performance is not simply a direct effect of central or peripheral fatigue, but is partly due to impairment of the ability to utilize stiffness-related elastic energy.

Bicycling↗
PubMed1998

Muscle damage induced by stretch-shortening cycle exercise.

PURPOSE: Strenuous stretch-shortening cycle exercise was used as a model to study the leakage of proteins from skeletal muscle. METHODS: The analysis included serum levels of creatine kinase (S-CK), myoglobin (S-Mb), and carbonic anhydrase (S-CA III). Blood samples from power- (N=11) and endurance-trained (N=10) athletes were collected before, 0, and 2 h after the exercise, which consisted of a total of 400 jumps. RESULTS: The levels of all determined myocellular proteins increased immediately after the exercise (P < 0.05-0.001) among both subject groups. In the endurance group, the protein levels increased (P < 0.05-0.001) further during the following 2 h after the exercise, and the ratio of S-CA III and S-Mb decreased (P < 0.05) in a before-after comparison. This was not the case among the power group despite their greater mechanical work (P < 0.001) and higher ratio of eccentric and concentric EMG activity of the leg extensor muscles (P < 0.05). CONCLUSIONS: The differences of the determined protein levels between the subject groups might be due to obvious differences in the muscle fiber distribution, differences in recruitment order of motor units, and/or differences in training background.

Adult↗
PubMed1991

Scientific, medical, and practical aspects of stretching.

This article addresses the medical, scientific, and practical aspects of stretching. Sections include information on the physiology of flexibility and stretching, stretching versus warm-up, and the clinical evaluation of flexibility. Detailed instructions for numerous stretching exercises for the major muscle groups are provided. Techniques for proper stretching are included.

Exercise↗
PubMed2001

Exercise-induced angiogenesis-related growth and transcription factors in skeletal muscle, and their modification in muscle pathology.

Angiogenesis is the process of formation of new blood vessels; it is generally a rare occurrence in the adult, although it is a common adaptive response to exercise training in skeletal muscle. Current thinking is that angiogenesis is mediated by diffusible angiogenic factors and that the angiogenic activity is regulated through the balance between stimulatory and inhibitory factors. Recent studies have shown that up-regulation of angiogenic factors occurs in response to increased muscle activity in skeletal muscle. The major putative angiogenic factor, vascular endothelial growth factor (VEGF), seems to increase to a greater extent and more consistently than other measured angiogenic factors, such as fibroblast growth factor-2 (FGF-2) and transforming growth factor-beta1 (TGF-beta1). While the regulating mechanisms in this response are not clear, present data indicate reduced oxygen tension and/or related metabolic alterations in the skeletal muscle as possible stimuli. Data on other angiogenic growth factors are limited, but an increase in endothelial cell-stimulating angiogenic growth factor (ESAF) has been observed in response to increased blood flow and muscle stretching. Therefore, different exercise associated stimuli may all contribute to exercise-induced angiogenesis in skeletal muscle, but possibly through differing angiogenic factors and mechanisms. Understanding these processes is important for the elucidation of mechanisms mediating exercise responsiveness in skeletal muscle, but also for the potential that such understanding might bring to the treatment and prevention of human diseases such as intermittent claudication.

Animals↗
PubMed1998

The effects of stretch parameters on eccentric exercise-induced damage to toad skeletal muscle.

Repeated contractions during which a muscle is stretched, known as eccentric contractions, have previously been shown to produce damage. This can be quantified by changes in various mechanical properties, of which reduction in tension and a shift in the optimum length for tension generation to longer lengths are examined here. The magnitude of these changes has been reported to depend strongly on the number of stretches, the amplitude of each stretch and the maximum tension reached. One proposed explanation of the changes predicts that muscle length should have a strong influence, but past reports have been contradictory on this point. Experiments were performed to test this hypothesis using whole toad sartorius muscles, which have the advantage of a relatively small passive tension, allowing a large range of lengths to be used. Initial length, amplitude of stretch and number of eccentric contractions were found by multiple linear regression to be the strong determinants of changes due to eccentric exercise. Velocity had a weak effect, and tension, varied only by varying the length of maximally activated muscles, was poorly correlated.

Animals↗