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Results for “Muscle Strength Dynamometer”

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At least 505 records · Page 28Linked to original sources

PubMed2000

Relationships between plantar flexor muscle stiffness, strength, and range of motion in subjects with diabetes-peripheral neuropathy compared to age-matched controls.

STUDY DESIGN: Descriptive study to compare relationships between muscle performance measures in 2 subject groups. OBJECTIVES: To determine the relationships between plantar flexor (PF) muscle stiffness, strength (concentric peak torque), and dorsiflexion (DF) range of motion (ROM) in subjects with diabetes who have peripheral neuropathy (n = 17, 10 men, 7 women; age = 58 +/- 11 years) and age-matched controls (n = 17, 10 men, 7 women; age = 62 +/- 6 years). BACKGROUND: The relationships between muscle stiffness, strength, and joint ROM have not been clearly established. Furthermore, the effect of neuromuscular pathology on these relationships is unknown. METHODS AND MEASURES: PF stiffness and strength measurements were obtained with an isokinetic dynamometer. DF ROM was measured with a goniometer. A Pearson correlation matrix was constructed for each subject group using stiffness, strength, and ROM variables. The percent contribution of passive torque to total torque was computed at 2 joint angles. RESULTS: In subjects with diabetes and peripheral neuropathy (DM-PN) peak concentric PF torque was positively correlated with passive torque at 5 degrees DF (r = 0.77), Stiffness #1 (r = 0.58), and Stiffness #2 (r = 0.50). The percentage of passive PF torque at 5 degrees DF was greater in subjects with DM-PN, compared to control subjects (29.3 +/- 9.4% versus 12.6 +/- 5.9%). CONCLUSIONS: The positive correlation between PF stiffness and strength, and the greater percentage of passive PF torque in subjects with DM-PN suggest that patients with decreased strength may use passive torque to maximize total torque. Therefore, treatment methods designed to decrease stiffness should be used cautiously.

Aged↗

PubMed2002

Pfannenstiel versus Maylard incision for cesarean delivery: A randomized controlled trial.

OBJECTIVE: To compare the Pfannenstiel incision with transverse muscle-cutting Maylard incision in women who had cesarean delivery. METHODS: Patients were assigned randomly to a Pfannenstiel or Maylard incision. Postoperative treatment was similar for each group. Surgical characteristics, complications, postoperative pain (visual analog scale, analgesic use), and related quality of life (1- and 3-month self-administered questionnaires) were analyzed. Abdominal wall muscle recovery was compared objectively by dynamometer. RESULTS: Fifty-four women had a Pfannenstiel incision and 43 had the Maylard incision. There were no differences in intraoperative characteristics, postoperative morbidity, or pain. Women's responses to the Nottingham Health Profile questionnaire at 1 and 3 months postoperatively and clinical and isokinetic testing for abdominal wall strength were similar between the two groups. CONCLUSION: Transecting the rectus muscle was no more deleterious than the Pfannenstiel incision. There was no difference in objectively measured abdominal wall strength.

Abdominal Muscles↗

PubMed2004

Factors related to postmenopausal muscle performance: a cross-sectional population-based study.

The aim of the present study was to investigate cross-sectionally the association of postmenopausal muscle strength with simple performance tests. A random sample of 1,166 naturally postmenopausal women (born 1932-1941) was selected from the Kuopio Osteoporosis Risk Factor and Prevention (OSTPRE) study cohort. Grip and quadriceps strength were measured with strain gauge dynamometers and reported in both absolute values (KPa and kg) and per kilogram of body mass (N cm(-2) kg(-1) and N kg(-1)). In addition, two performance tests, 'ability to stand on one foot' and 'ability to squat down to touch the floor' were carried out. A five-category self-assessment of overall health ('very good', 'good', 'moderate', 'bad', and 'very bad') was obtained by postal questionnaire. The women that were able to stand on one foot and able to squat down to touch the floor had greater grip and quadriceps strength than their counterparts ( P<0.001 and P<0.03 in ANOVA, respectively). In addition, self-assessed health had a strong positive association with muscle strength in the grip and leg extensor muscles in ANOVA ( P<0.001 between 'very good' and 'moderate' or poorer state of health) and regression model ( P<0.001). Adjustment for age, duration of menopause, body mass, height, physical activity level, use of HRT, and number of diseases and medications did not change any of the main effects. Also, there were no differences in results between absolute measurement values and values reported per kilogram of body mass. According to the present study, a simple performance test may be useful in the prediction of postmenopausal muscle strength. Furthermore, self-assessed state of health is strongly associated with muscle strength in postmenopausal women.

Body Constitution↗

PubMed1996

Quadriceps muscle training in a restricted range of motion: implications for anterior cruciate ligament deficiency.

This study examined the transferability of strength gains associated with training in a limited range of motion, and at a specific joint angular velocity, to a different part of the range of motion. Work was assessed in control (N = 14) and experimental (N = 14) groups that performed baseline tests on a Kin-Com dynamometer at 1.05, 2.09, and 3.14 rad/sec, over a range of motion from 90 degrees flexion to full extension. The experimental group then underwent training consisting of three sets of eight maximum-effort knee extensions on a Kin-Com dynamometer at a joint angular velocity of 2.09 rad/sec, three times per week for 8 weeks. The range of motion at which they trained was 90 degrees to 45 degrees. After training, baseline tests were repeated in both groups. The findings showed that the work done by the quadriceps muscles of the experimental group increased significantly (p < .05) in the training range of motion across all joint angular velocities. In the untrained range of motion, the work done by the experimental group increased significantly (p < .05) only at the training angular velocity of 2.09 rad/sec. These findings provide evidence that training in a range of motion in which anterior shear forces are low can lead to changes in strength in the range of motion in which anterior shear forces are high. Hence, such exercise is of potential benefit to the anterior cruciate ligament-deficient individual.

Adult↗

PubMed1995

Strength and cross-sectional areas of reciprocal muscle groups in the upper arm and thigh during adolescence.

The purpose of this study was to investigate the development in muscle cross-sectional area (CSA) and strength capability of the reciprocal muscle groups in the upper arm and thigh. Subjects were 130 boys aged 7 to 18 years; 7-9 yr aged-group (n = 30), 10-12 yr (n = 30), 13-15 yr (n = 35), and 16-18 yr (n = 35). Anatomical CSAs of elbow flexors (EF), elbow extensors (EE), knee flexors (KF) and knee extensors (KE) were determined with a B-mode ultrasound apparatus. Isokinetic strength during elbow or knee extension as well as elbow or knee flexion was measured by using a Cybex II isokinetic dynamometer at the pre-set constant velocity of 60 degrees/s. The effect of age associated with a significant increase in both CSA and strength with a marked increase in 13-15 yr. The elder aged-groups had a significantly higher ratio of strength to muscle CSA than in the lower aged-groups. The effect of age on EF/EE CSA ratio was not significant, but EF/EE strength ratio was the highest in 16-18 yr and the lowest in 7-9 yr. With advancing age, KF/KE CSA ratio had a tendency to increase, but KF/KE strength ratio remained almost unchanged. These results indicate that (1) children in the pre-puberty or the early stage of puberty do not develop strength in proportion to their muscle CSA, and (2) the flexors and extensors in limbs have reciprocally different growth rates in either CSA or strength even in the same region.

Adolescent↗

PubMed1997

Stretch-shortening cycle in patients with upper motor neuron lesions due to stroke.

The stretch-shortening cycle (SSC) is a natural muscle function where a concentric action is preceded by an eccentric action, and this leads to a higher concentric torque value in healthy persons. This study aimed to investigate the concentric torque output with and without preceding eccentric or isometric actions in patients with upper motor neuron lesions due to cerebro-vascular disease. Strength measurements of the plantar flexions were made in a dynamometer at different angular velocities (120 degrees.s-1 and 240 degrees.s-1) and recordings of electromyogram (EMG) were made simultaneously. The assessment was based on comparisons of the concentric torque values with and without preceding actions. The study showed a significantly higher percentage increase in concentric torque values after preceding actions in the affected leg compared with the nonaffected leg except at 120 degrees.s-1 with preceding isometric action. Relative EMG changes showed no differences between the legs except at 120 degrees.s-1 with preceding isometric action. We would suggest that the higher performance of the affected leg was caused by better utilization of elastic energy due to muscle stiffness which, despite reduced muscle strength, may have returned the patient's functional ability towards normal.

Aged↗

PubMed2005

Learning effect of isokinetic measurements in healthy subjects, and reliability and comparability of Biodex and Lido dynamometers.

The aim of this study was to examine the learning effect during a set of isokinetic measurements, to evaluate the reliability of the Biodex System 3 PRO dynamometer, and to compare the Biodex System 3 PRO and the Lido Active dynamometers on both extension and flexion over the elbow and the knee at 60 degrees s(-1). Thirteen (nine women, four men) healthy participants were measured five times using the Biodex and once using the Lido dynamometer. The intervals between the first four tests were 20 min, and 1 week between tests 4 and 5. Between Biodex and Lido measurements there was a 20 min time interval. When comparing the first five measurements (Biodex), no systematic effect over time and an excellent reliability were found with respect to elbow and knee flexion and extension. No difference in muscle strength (Nm) between the Biodex and Lido was observed for knee flexion (P = 0.59), knee extension (P = 0.18) and elbow extension (P = 0.63). However, elbow flexion showed a 14.8% (95% CI: 11.2-18.4%; P = 0.0001) higher peak torque on Biodex. In conclusion, no learning effect was observed and the Biodex proved to be a highly reliable isokinetic dynamometer. A difference was observed when comparing Biodex and Lido on elbow flexion, but the difference did not outrange the expected variation found with a typical isokinetic measurement, which is why both sets of equipment seem applicable in clinical practice.

Adolescent↗

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↗

PubMed1997

The effect of training status on the serum creatine kinase response, soreness and muscle function following resistance exercise.

Untrained individuals develop muscle soreness and increased serum creatine kinase (CK) activity in the blood after strenuous, unaccustomed exercise. An unpublished observation in our laboratory revealed that trained weightlifters also experience considerable soreness after unaccustomed exercise, but may not show a dramatic CK response. This study examined the CK and soreness responses to strenuous exercise in weightlifters (TR, n = 10) and untrained subjects (UTR, n = 10). Trained subjects had a minimum of three years weightlifting experience, and regularly performed squats and leg presses. Untrained subjects had not participated in any regular resistance exercise for the past three years. Following two acclimation sessions, subjects reported to the lab on seven consecutive days and on the tenth day after knee extensor exercise. Weight training sessions occurred on day 1 for the knee extensors (KE) and day 2 for the knee flexors (KF). The weight training consisted of these exercises (sets): squat (5), leg press (3), leg extension and lunge (3) for the KE, double leg curls (6), single leg curls (3), stiff-legged deadlifts (4, TR group only) for the KF at 12 RM for all exercises. To document the stress due to exercise, the loss in strength (isometric peak torque, IPT) was assessed on a Biodex isokinetic dynamometer. Maximal voluntary IPT of the KE at 90 degrees and the KF at 80 degrees decreased 17-30% with no significant differences between groups. Muscle soreness during simulated squat leg curl movement was assessed by a 100 mm visual analog scale (VAS). Average peak KE soreness was 76 mm for TR and 58 mm for UTR, KF soreness was 60 mm for TR and 47 mm for UTR post-exercise. Serum CK levels were significantly different between groups with a peak of 1349 IU for TR and 3272 IU for the UTR (p < 0.01). Although the TR group experienced greater soreness than the UTR, peak serum CK activity was significantly lower, suggesting that trained individuals can develop severe soreness without the same degree of increase in serum CK activity observed in untrained individuals.

Adult↗

PubMed1986

Pressure from the lips on the teeth and malocclusion.

The relationship between lip strength and lip pressure (pressure from the lips on the teeth) was studied in 84 children (aged 7 to 16 years) with varying types of malocclusion. The lip strength was recorded with a dynamometer. The lip pressure was measured on the upper and lower central incisors in the rest position, and during chewing and swallowing of crispbread. The lip pressure measurements were made with an extraoral pressure transducer incorporated in a water-filled system with an intraoral mouthpiece. The muscle activity of the lips was recorded electromyographically. Bite and facial morphologies were studied on dental casts and profile cephalograms. There was no correlation between lip strength and lip pressure. Lip strength was lower in children with Angle Class II, Division 1 malocclusion than in children with Class I malocclusion. The lip pressure on the upper incisors, on the other hand, was higher in Class II, Division 1 than in Class I malocclusion, and was lowest in children with Class II, Division 2 malocclusion. The findings suggest that the pressure from the lips on the teeth is a result of the incisor position.

Adolescent↗

PubMed1993

Reliability of isokinetic and isometric measurement of leg strength on men with mental retardation.

The purpose of this study was to determine the reliability of isokinetic and isometric measurement of strength for tests of knee extension and hip abduction on men with mental retardation (MR). In addition, the relationships between isokinetic measures of peak torque (PT) and total work (TW) and isometric peak torque were examined. Twenty-two men with mild to moderate MR were tested for isokinetic knee extension and hip abduction strength on a Musculoskeletal, Evaluation, Rehabilitation and Conditioning (MAREC) systems dynamometer at velocities of 60 and 30 degrees/sec, respectively. Isometric peak torque was determined by an examiner using a Nicholas Manual Muscle Tester (NMMT). Intrarater correlation coefficients for the isokinetic PT and TW scores ranged from .97 to .99, whereas coefficients for isometric NMMT scores ranged from .97 to .98. Pearson correlation coefficients between PT and TW scores ranged from .76 to .93. Coefficients between isokinetic and isometric scores ranged from .43 to .73. These results indicate that highly reliable isokinetic and isometric measurements can be obtained on men with MR. Also, the relatively simple measurement of PT may be the isokinetic parameter of choice at the clinical setting. Moderate relationships between NMMT and isokinetic scores were found, indicating that the generalization of test scores from one test modality to another is not warranted.

Adult↗

PubMedDate not supplied

[Therapeutic physical exercise for patients after the amputation of the lower extremities at the sanatorium stage of rehabilitation].

The authors propose a set of therapeutic exercises developed to prevent degenerative-dystrophic processes and to improve locomotor function in patients undergoing sanatorium treatment after lower limb amputation. Swimming and loading exercises have improved strength and performance of spinal muscles, amputated and supporting limb, reduced osteoporosis of the stump bone fragment. The efficacy of the above approach was evaluated by dynamometry on the test-dynamometer Biodex and by ultrasound osteometry.

Adult↗

PubMed2000

Ability of closed and open kinetic chain tests of muscular strength to assess functional performance.

The purpose of this study was to investigate the ability of closed and open kinetic chain tests of muscular strength to assess functional performance. Sixteen healthy male subjects, with a mean (+/-SD) age, body mass and height of 27+/-5 years, 78+/-9 kg and 183+/-9 cm, respectively, volunteered to participate in the study. In the closed kinetic chain test (involving muscles working across multiple joints), the subjects performed a 3 repetition maximum (3 RM) barbell squat. The open kinetic chain test (involving muscles working across a single joint) consisted of a concentric isokinetic knee extension at an angular velocity of 60 degrees/s, and was performed using a Kinetic Communicator II dynamometer. The test of functional performance (vertical jump) was performed with the subject standing erect, quickly performing a countermovement jump for maximal height. Moderately strong significant (P<0.05) correlations between the test of functional performance and the closed and open kinetic chain tests of muscular strength were noted, r=0.51 and r=0.57, respectively. It is suggested that the effect of training or rehabilitation interventions should not be based exclusively on tests of muscular strength. Rather, various forms of dynamometry including functional performance tests could be recommended.

Adult↗

PubMed2004

Reproducibility of maximal quadriceps strength and its relationship to maximal voluntary activation in postpoliomyelitis syndrome.

OBJECTIVES: To determine what changes in maximal isometric strength can be detected in a symptomatic quadriceps muscle in patients with postpoliomyelitis syndrome (PPS) and to investigate the association between the variability in maximal strength and maximal voluntary activation (MVA). DESIGN: Repeated-measures over a 3-week interval. SETTING: University hospital. PATIENTS: Convenience sample of 65 patients with PPS. INTERVENTION: Dynamometer testing. MAIN OUTCOME MEASURES: Maximal voluntary contraction (MVC) torque of the quadriceps was measured with a Kin-Com dynamometer and MVA was determined by twitch interpolation. RESULTS: The mean difference between the 2 consecutive measurements was -0.7+/-12.8 Nm (95% confidence interval [CI], -3.9 to 2.5). The test-retest reliability was excellent for MVC torque (intraclass correlation coefficient [ICC]=.96; 95% CI,.93-.98) and moderate for MVA (ICC=.73; 95% CI,.56-.85). The smallest detectable change in MVC torque was 25% for an individual. The variability in MVA explained 18% of the variability in maximal strength. CONCLUSIONS: Variability in maximal quadriceps strength, measured with a fixed dynamometer, was large and partly related to variability in MVA. This implies that even with optimally standardized strength testing, a follow-up of many years is required to objectify progression of quadriceps weakness in an individual patient with PPS. To demonstrate changes in strength in groups of patients in follow-up or intervention studies, feasible sample sizes are required.

Adult↗

PubMed2001

Strength capabilities of knee extensor muscles in junior speed skaters.

BACKGROUND: The present study aimed to investigate the gender- and age-related profiles of junior speed skaters in strength capabilities during both single and repetitive maximal contractions. METHODS: The subjects were 19 male (age = 17.1 +/- 0.2 years, X +/- SE) and 13 female skaters (16.9 +/- 0.2 years). Isokinetic knee extension torque (T) developed concentrically in a single contraction at three constant velocities of 1.05, 3.14 and 5.24 rad/sec and 50 repetitive maximal contractions at 3.14 rad/sec was measured using an isokinetic dynamometer. In addition, a B-mode ultrasound apparatus was used to determine the cross-sectional area (CSA) of the quadriceps femoris muscle at mid-thigh. RESULTS: For the junior skaters, T values at three velocities of 1.05, 3.14 and 5.24 rad/sec and the mean value of isokinetic torque (MT) for every five consecutive trials in the first 25 maximal contractions were similar in both genders when they were expressed relative to the product of the cross-sectional area (CSA) of the quadriceps femoris muscle and lower limb length, T/CSAL and MT/CSAL, respectively. However, the males showed significantly higher MT/CSAL values than the females in the last 25 repetitions of the endurance test. In the comparisons between junior and reference senior skaters, T/CSAL for both genders and MT/CSAL for the females showed little age-related difference. For the males, however, MT/CSAL values in the first 15 repetitions of the endurance test were significantly lower in the junior skaters than in the senior ones. CONCLUSIONS: The present results indicate that the strength capabilities of junior speed skaters in a single maximal contraction will be similar in both genders when the difference in muscle size is normalized. However, the junior male skaters may be less fatiguable than the junior female ones in repetitive maximal contractions. Moreover, the comparison between junior and senior skaters suggests that, in postadolescence, males might be more trainable than females to improve torque output during short-term repetitive maximal contractions beyond that achieved during adolescence.

Adolescent↗

PubMed1997

The ability of male and female clinicians to effectively test knee extension strength using manual muscle testing.

It has been suggested that the accuracy of manual muscle testing is dependent on examiner strength. Our purpose was to relate male and female clinicians' upper extremity strength to their ability to challenge the quadriceps and detect weakness in patients using manual muscle testing. Quadriceps muscles of seven men and 12 women with postpoliomyelitis were tested manually by a male and female clinician while forces were recorded with a hand-held dynamometer. Patients' maximal isometric knee extension force was recorded with a Lido dynamometer and clinicians' maximal vertical push force was recorded with the hand-held dynamometer. Manual muscle testing forces, patient maximum quadriceps forces, and examiner push forces were compared with repeated measures analysis of variance. Female examiners' maximal vertical push force (235.7 +/- 54.3 N) was not significantly different from either female or male patients' maximal quadriceps force (166.8 +/- 66.7 N and 341.6 +/- 123.7 N) but was only 60% and 40% of the isometric knee extension forces generated by a group of normal women and men. Male examiners were significantly stronger (357.0 +/- 93.4 N) than the female but not the male patients and produced 90% and 60% of the normal isometric quadriceps forces for women and men. Examiners gave appropriate grades in 30 of 38 tests. Examiner strength limits detection of moderate quadriceps weakness with manual resistance. Most of the muscle test grades, however, were appropriate, given the examiner's upper extremity strength. Clinicians using manual muscle testing should determine their maximal vertical push force and the extent of weakness they can detect.

Exercise↗

PubMedDate not supplied

[Evaluation of the capacity of work using upper limbs after radical latero-cervical surgery].

Evaluation of arm work capacity after radical neck surgery. The aim of this paper is to describe an approach for the assessment of work capacity in patients who underwent radical neck surgery, including those treated with radiation therapy. Nine male patients, who underwent radical neck surgery 2 months before being referred to our Unit, participated in the study. In addition to manual muscle strength test, we performed the following functional evaluations: 0-100 Constant scale for shoulder function; maximal shoulder strength in adduction/abduction and intrarotation/extrarotation; instrumental. We measured maximal isokinetic strength (10 repetitions) with a computerized dynamometer (Lido WorkSET) set at 100 degrees/sec. During the rehabilitation phase, the patients' mechanical parameters, the perception of effort, pain or discomfort, and the range of movement were monitored while performing daily/occupational task individually chosen on the simulator (Lido WorkSET) under isotonic conditions. On this basis, patients were encouraged to return to levels of daily physical activities compatible with the individual tolerable work load. The second evaluation at 2 month confirmed that the integrated rehabilitation protocol successfully increased patients' capacities and "trust" in their physical capacity. According to the literature, the use of isokinetic and isotonic exercise programs appears to decrease shoulder rehabilitation time. In our experience an excellent compliance has been noted. One of the advantages of the method proposed is to provide quantitative reports of the functional capacity and therefore to facilitate return-to-work of patients who underwent radical neck surgery.

Activities of Daily Living↗

PubMed2005

Reconstructed hip joint position and abductor muscle strength after total hip arthroplasty.

We evaluated 60 limbs in 30 patients with unilateral primary total hip arthroplasty and nondiseased contralateral hip. The ratio of femoral offset (FO) to the body weight lever arm (FO ratio) and the ratio of the height of hip center (HC) to pelvic height (HC ratio) were calculated on radiographs. Isometric hip abductor strength was measured by dynamometer. The ratio of normalized strength of the reconstructed side to that of the nonoperated side was calculated (strength ratio). The FO ratio correlated positively to the strength ratio (r = 0.491; P = .0059), whereas the HC ratio correlated negatively (r = -0.568; P = .0011). Slight increase of FO ratio along with restoration of normal hip joint center erring on the side of slight inferomedial cup positioning appeared to optimize hip abductor function.

Aged↗