PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Muscle Strength”

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 991 records · Page 55Linked to original sources
PubMed1996

Recovery of muscle strength following arthroscopic meniscectomy.

The purpose of this study was to investigate the time course of spontaneous recovery (no supervised training) of muscle torques in the first 3 months postarthroscopic partial meniscectomy. This information will then be used to plan a clinical trial investigating the effects of rehabilitation following arthroscopic meniscectomy. Knee extensor and flexor strength was evaluated at four different velocities (60, 120, 180, and 240 degrees/sec) preoperatively and every 2 weeks from weeks 2-12 postsurgery. Eight subjects were evaluated on a Cybex II+ and 14 subjects were evaluated on a Cybex II isokinetic device. A repeated measures analysis of variance was used to determine possible side (involved and uninvolved), speed (60, 120, 180, and 240 degrees/sec), or time (preoperative, 2, 4, 6, 8, 10, and 12 weeks postoperatively) effects as well as possible interactions between these factors. Prior to partial meniscectomy, the involved quadriceps was significantly weaker than the uninvolved quadriceps only at 60 degrees/sec (15%). A further decrease in torque was noted at 2 (25-40% deficit depending on the velocity) and 4 weeks postsurgery at all speeds (17-25%). The quadriceps recovered to preoperative values by 4-6 weeks postsurgery and stabilized at this level until the end of the study, at which time the quadriceps remained weaker than the contralateral side at 60 degrees/sec (14%) and 120 degrees/sec (12%). Prior to surgery, the involved hamstrings were comparable with the uninvolved hamstrings. Although significant differences between sides were found at week 2 postsurgery at 60 (23%) and 120 degrees/sec (17%), the hamstrings were fully recovered by 4 weeks postoperatively. In conclusion, although the quadriceps may recover to preoperative levels by 4-6 weeks following partial meniscectomy, further recovery does not appear to be possible without training as the quadriceps remains weaker than the contralateral side up to 12 weeks postsurgery.

Adult↗
PubMed2002

Electrophysiologic findings and muscle strength grading in brachioplexopathies.

The electrophysiological evaluations and the British Medical Research Council (MRC) scale (0-5) findings of target muscles in brachioplexopathies before surgery and 1 year postsurgery were conducted. Each component of the brachial plexus was analyzed in 15 patients with injuries, among them, to 5 roots, 19 trunks, 7 cords, and 13 terminal nerves. In each of these cases, neurolysis and/or nerve transfer and/or neurotization were performed, within 3 weeks to 6 months after the injury was incurred, to ameliorate the resulting severe disabilities. The degrees of impairment were graded using a modified version of Dumitru's and Wilbourn's scale (mild: normal to slight decrease of SNAP amplitude and CMAP amplitude, and occasional denervation; moderate: profound decrease of SNAP amplitude and CMAP amplitude, constant denervation, and normal to slight decrease in motor unit recruitment; severe: absent SNAP amplitude, absent CMAP amplitude, marked denervation, and profound decrease or no volitional motor unit recruitment. mild = 1; moderate = 2; severe = 3). The motor power of the target muscles was graded through MRC scores. The presurgical versus postsurgical differences in the severity of the injury to each brachial plexus component, and differences in the grading of target muscle power, were calculated through the Wilcoxon signed-rank test. The presurgical degrees of the severity of injury, as measured by the electromyography (EMG) were 3.00 +/- 0.00 (mean +/- SD) in root, 2.84 +/- 0.50 in trunk, 3.00 +/- 0.00 in cord, and 2.85 +/- 0.38 in terminal nerves. The postsurgical results were 2.60 +/- 0.55 in root, 2.53 +/- 0.70 in trunk, 2.43 +/- 0.53 in cord, and 1.77 +/- 0.73 in terminal nerves. There was significant improvement at the trunk, cord, and terminal nerve levels after repair, but not at the root levels. Moreover, although the MRC grading showed significant motor recovery in the infraspinatus, deltoid, biceps, and triceps muscles, there was little apparent improvement in the pectoralis major, EDC, APB, and ADM muscles. Nerve repair was notably successful in all plexuses except at the root level. However, our cases demonstrated only poor motor power gains in the forearm and the hand muscles. Consequently, future surgical techniques for brachioplexopathy repairs need further improvement.

Adolescent↗
PubMed1993

Twitch interpolation technique in testing of maximal muscle strength: influence of potentiation, force level, stimulus intensity and preload.

The aim was to study the methodological aspects of the muscle twitch interpolation technique in estimating the maximal force of contraction in the quadriceps muscle utilizing commercial muscle testing equipment. Six healthy subjects participated in seven sets of experiments testing the effects on twitch size of potentiation, time lag after potentiation, magnitude of voluntary force, stimulus amplitude, stimulus duration, angle of the knee, and angle of the hip. In addition, the consequences of submaximal potentiation on the estimation of maximal force from twitch sizes were studied in five healthy subjects. We found an increase in twitch size with increasing levels of potentiation and twitch size decreased exponentially following potentiation. We found a curvilinear relationship between twitch size and voluntary force, and these properties were more obvious when the stimulation intensity of the preload was reduced. The relationship between twitch size and force was only linear, for force levels greater than 25% of maximum. It was concluded that to achieve an accurate estimate of true maximal force of muscle contraction, it would be necessary for the subject to be able to perform at least 75% of the true maximal force.

Adult↗
PubMed1979

[Effect of the contraction of other muscle groups on muscle strength, latency period and endurance].

The following investigation was undertaken in connection with Sechenov's idea on mutual influence of muscles performing different work. It deals with the influence on test muscle (TM) efficiency of other simultaneously working muscles (SWM). It was shown that tension of SWM or maintenance of complex postures exert a negative influence on the force and latency of the visual-motor reaction and the static effort endurance. The mechanism involved is external inhibition. After its extinction as a result of repeated combinations of both activities the degree of lowering of TM activity grows less and finally its improvement is observed as compared to data obtained in the absence of SWM contractions. It is suggested that when external inhibition is extinguished impulses arising in SWM reinforce and improve according to the law of dominant the functions of nervous centers regulating activities of the TM.

Humans↗
PubMed1999

Improving calf muscle strength in patients with spastic equinovarus deformity by transfer of the long toe flexors to the Os calcis.

The split tibialis anterior tendon transfer (SPLATT), Achilles tendon lengthening, and toe flexor release are proven and effective procedures for correcting a spastic equinovarus deformity of the foot. Paresis is a prominent feature of upper motoneuron syndrome. Lengthening the Achilles tendon, although necessary to correct the equinus, further weakens the gastrocnemius-soleus muscle group. The calf paresis commonly results in the need for an ankle-foot orthosis (AFO) during ambulation. Previous studies have shown that despite the correction of the equinovarus deformity, only one third of patients were able to ambulate without an AFO. The need for continued use of an AFO was because of insufficient calf strength to stabilize the tibia during late stance when the body mass is anterior to the ankle joint. This study prospectively evaluated the results of transfer of the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) to the os calcis in 30 patients. The transfer was done in an effort to augment the strength of the gastrocnemius-soleus muscle complex. Twenty-five patients in group I (the control group) underwent SPLATT, Achilles tendon lengthening, and toe flexor release. Thirty patients in group II (the study group) underwent the identical procedures plus the additional FHL and FDL transfer to the os calcis. Postoperatively, the varus and toe flexion deformities were corrected in all feet. In group II, two feet had a mild residual equinus that did not interfere with ambulation. Of the 11 patients who were not independent community ambulators in group I, 7 (64%) improved ambulatory status by at least one level after surgery. Of the 15 patients who were not independent community ambulators in group II, 14 (93%) improved ambulatory status by at least one level after surgery. In group I, 10 of 25 (40%) of the patients were brace free at follow-up. In group II, 21 of 30 (70%) were brace free at follow-up (c2, P =.025). These results indicate that the addition of an FHL and FDL transfer to the os calcis at the time of SPLATT, Achilles tendon lengthening, and toe flexor release improves calf strength and allows greater increase in function and less reliance on orthotics.

Achilles Tendon↗
PubMed1978

Muscle strength and power changes during maximal isokinetic training.

This study investigated the effects of short duration, high intensity training on skeletal muscle. The extensors and flexors of the knee were tested and exercised by means of an isokinetic dynamometer. Measurements of peak torque were obtained at velocities ranging from 0 degrees/sec (isometric) to 300 degrees/sec through a distance of 90 degrees. Total work output was measured during repeated knee extensions and flexions for work tasks of 6 sec and 30 sec duration. A 1-min test of repeated maximal contractions was administered to examine muscular fatiguability before and after training. The subjects trained one leg with repeated 6 sec exercise bouts, while the other leg was trained using repeated 30 sec bouts. All training and testing was executed at near maximal force and at a constant velocity (180 degrees/sec). The subjects trained four times per week for a period of seven weeks. The daily work output was equal for the 6 and 30 sec training legs. Results indicate that: (1) isokinetic training programs of 6 and 30 seconds duration can significantly (P less than .05) increase peak muscular torque; (2) training velocity may be an important consideration in improving peak torque; (3) total work output was increased an average of 30% with either training at relatively slow (60 degrees/sec) or fast (180 degrees/sec) velocities; (4) both training programs significantly reduced the fatiguability of the knee extensor muscles.

Adult↗
PubMedDate not supplied

Comparison of muscle strength and flexibility between the preferred and non-preferred leg in English soccer players.

Most soccer players have a favoured foot for kicking the ball, and it is believed that this preference may lead to an asymmetry in the strength and flexibility of the lower extremities. This study was designed to determine whether asymmetry in strength and flexibility are present in the legs of soccer players.Forty-one elite and sub-elite soccer players (age 23.4 +/- 3.8 years; height 1.81 +/- 0.06 m; body mass 81.7 +/- 9.9 kg) were studied (data are presented as mean +/- SD). The dynamic strength of knee flexors (hamstrings) and knee extensors (quadriceps) was measured using an isokinetic dynamometer at angular velocities of 1.05, 2.09, 5.23 rad/s (in a concentric mode) and 2.09 rad/s (in an eccentric mode). The concentric strength ratio (hamstrings(conc)/quadriceps(conc)) and the dynamic control ratio (hamstrings(ecc)/quadriceps(conc)) were computed. Hip joint flexibility (in flexion) was measured using a goniometer.A significant difference between the preferred and non-preferred leg was found in the knee flexors at 2.09 rad/s (119 +/- 22 versus 126 +/- 24 Nm; P < 0.05) and for the dynamic control ratio (0.79 +/- 0.13 versus 0.84 +/- 0.16 Nm; P < 0.05). In both cases the knee flexors of the preferred leg were weaker than those of the non-preferred leg. A total of 28 of the 41 players (68%) had significant musculoskeletal abnormality (imbalance >10%) in one or more specific muscle groups. No significant differences were found in flexibility of the hip joint between the preferred and non-preferred leg (P > 0.05). It is concluded that the lower strength of the knee flexor muscles of the preferred leg may be associated with the differential use of these muscle during the kicking action and thus constitutes a unique training effect associated with soccer. This in turn can lead to muscular imbalance which is generally regarded as an injury risk factor.

Adult↗
PubMed1988

Changes in voluntary muscle strength, somatosensory transmission and skin temperature concomitant with pain relief during autotraction in patients with lumbar and sacral root lesions.

Earlier clinical observations of rapid changes of certain neurological dysfunctions after autotraction treatment of patients with lumbar and sacral root affections have been evaluated by objective registration methods. Isokinetic recordings of maximal voluntary strength showed that in 6 out of 8 patients, weakness of the foot dorsal flexor muscles could be more or less completely restored after one session of autotraction resulting in pain relief. In a group of patients with clinical signs of impaired sensibility, the low or abolished SEP responses to nerve stimulation on the affected side were restituted in 4 out of 5 cases during autotraction. The asymmetric leg skin temperatures in 10 patients with sciatic pain levelled off in the 6 cases obtaining pain relief by the traction. The results suggest a causal relationship between pain relief and restitution of certain neurological deficits.

Adult↗
PubMed1982

Muscle strength and balance in post-stroke patients.

Isokinetic torque of the knee and elbow during maximal extension and flexion and isometric strength of the handgrip, as well as balance and some circulatory variables, were tested in 37 patients one year after an acute stroke. Correlations with locomotion, household work and other activities of daily living (ADL) were tested. Male patients who had received special activation on the ward for up to 4 weeks after the stroke showed a significantly smaller difference in strength between the paretic and non-paretic knee at an angular velocity of 90 degrees per second than males who had received only routine activation on their ward. There was a high correlation between locomotion and the isokinetic torque of the paretic knee and also between locomotion and balance. The correlations between elbow strength and ADL functions were weaker. It was concluded that the evaluation of the isokinetic muscle torque of the knee and the balance tests are valid instruments for estimating functional capacity after a stroke.

Activities of Daily Living↗