Maximal Isokinetic Muscle Strength Research Articles

Pain sensitivity and shoulder function among breast cancer survivors compared to matched controls: a case-control study

ObjectivePersistent pain and loss of shoulder function are common adverse effects to breast cancer treatment, but the extent of these issues in comparison with healthy controls is unclear for survivors beyond 1.5 years after treatment. The purpose of this study was to benchmark differences in pressure pain thresholds (PPT), maximal isokinetic muscle strength (MIMS), and active range of motion (ROM) of females with persistent pain ≥1.5 years after breast cancer treatment (BCS) compared with pain-free matched controls (CON), and examine the presence of movement-evoked pain (MEP) during assessment of MIMS.MethodsThe PPTs of 18 locations were assessed using a pressure algometer and a numeric rating scale was used to assess intensity of MEP. Active ROM and MIMS were measured using a universal goniometer and an isokinetic dynamometer, respectively.ResultsA two-way analysis of variance revealed that PPTs across all locations, MIMS for horizontal shoulder extension/flexion and shoulder adduction, active ROM for shoulder flexion, horizontal shoulder extension, shoulder abduction, and external shoulder rotation were significantly lower for BCS compared with CON (P < 0.05). MEP was significantly higher for BCS and MEP intensity had a significant, negative correlation with PPTs (P < 0.01).Discussion/conclusionBCS with persistent pain ≥1.5 years after treatment demonstrates widespread reductions in PPTs and movement-specific reductions in MIMS and active ROM of the affected shoulder, along with MEP during physical performance assessment.Implications for cancer survivorsBCS with persistent pain ≥1.5 years after treatment shows signs of central sensitization and may benefit from individualized rehabilitation.

Gonartrozlu Yaşlı Hastada D Vitamininin Kas Gücü ve Fonksiyonel Durum Üzerine Etkisi

Introductıon: The aim of this study was to evaluate the effects of vitamin D levels on pain intensity, muscle strength and functional status of elderly patients with osteoarthritis of the knee. &#x0D; Methods: Eighty one patients with osteoarthritis of the knee were enrolled in this study. The pain was measured with visual analogue scale (VAS). Western Ontario and McMaster University Arthritis Index (WOMAC) was used to evaluate pain, stiffness, and physical function. The maximum isokinetic muscle strength and the peak torque/body weight values were measured. &#x0D; Results: The patients were divided into two groups according to their 25 (OH) vitamin D levels: Group 1 consisted of patients whose 25 (OH) vitamin D levels were below 20 ng/ml and Group 2 comprised those with levels above 20 ng/ml. The VAS scores, the mean WOMAC pain, function and total scores were higher in Group 1 than Group 2. The maximal isokinetic muscle strength of extensor and flexor muscles of the knee and the peak torque/body weight values were significantly lower in Group 1 than in Group 2 (p

Absolute and relative reliability of pain sensitivity and functional outcomes of the affected shoulder among women with pain after breast cancer treatment.

Breast cancer survivors (BCS) are often characterized by decreased pressure pain thresholds (PPT), range of motion (ROM) and strength in and around the shoulder affected by the treatment. This intra-rater reliability study was to establish the relative and absolute reliability of PPT's, active ROM and maximal isokinetic muscle strength (MIMS) of the affected shoulder in BCS with persistent pain after treatment. Twenty-one BCS participated in the study. The PPTs of 17 locations and pain intensity were assessed using a pressure algometer and a numeric rating scale. The ROM was measured using a universal goniometer and MIMS was measured using an isokinetic dynamometer. Relative reliability was estimated using intra class correlation coefficient (ICC), and absolute reliability using standard error of measurement (SEM). Minimum detectable change (MDC) was calculated from SEM. The ICCs for PPTs ranged from 0.88-0.97, with SEM values ranging from 12.0 to 28.2 kPa and MDC ranging from 33.2 to 78.2 kPa. The ICCs for ROM ranged from 0.66-0.97, with SEM values ranging from 3.0 to 7.5° and MDC ranging from 8.4 to 20.8°. Finally, ICCs for MIMS ranged from 0.62-0.92, with SEM values ranging from 0.03 to 0.07 Nm/Kg FFM and MDC ranging from 0.09 to 0.19 Nm/kg FFM. The results of this study indicate that PPTs, ROM and MIMS can be measured reliably on the affected shoulder in BCS with pain after treatment. This offer the possibility of using these measures to assess the effectiveness of interventions in this population.

Comparative analysis of quadriceps and hamstrings strength in knee osteoarthritis before and after total knee arthroplasty: a cross-sectional study

ObjectiveCompare the maximal isokinetic muscle strength of knee extensor and flexor muscles between patients with knee osteoarthritis and patients submitted to total knee arthroplasty. MethodsVolunteers were divided into five groups (n=20): Control; Ahlbäck I and II; Ahlbäck IV; six months after total knee arthroplasty; 12 months after total knee arthroplasty. An isokinetic knee strength evaluation was conducted for the quadriceps and hamstrings at 60°/s. ResultsSignificant differences in the peak torque of the quadriceps and hamstrings were found among the groups (p<0.001). The Ahlbäck IV, six-month, and 12-month postoperative groups demonstrated lower values when compared to the Control and Ahlbäck I and II groups. When percentage values were compared to the Control group, mean differences ranged from 7% to 41%. ConclusionPatients with healthy knees or early stage osteoarthritis have higher quadriceps and hamstrings strengths than those with a more advanced stage of the disease, even after knee replacement. These findings suggest that the traditional rehabilitation programs do not recover strength to levels observed in individuals without knee osteoarthritis.

Análise comparativa da força do quadríceps e dos isquiotibiais na osteoartrite do joelho antes e após a artroplastia total do joelho: um estudo transversal

ObjectiveCompare the maximal isokinetic muscle strength of knee extensor and flexor muscles between patients with knee osteoarthritis and patients submitted to total knee arthroplasty. MethodsVolunteers were divided into five groups (n=20): Control; Ahlbäck I and II; Ahlbäck IV; six months after total knee arthroplasty; 12 months after total knee arthroplasty. An isokinetic knee strength evaluation was conducted for the quadriceps and hamstrings at 60°/s. ResultsSignificant differences in the peak torque of the quadriceps and hamstrings were found among the groups (p<0.001). The Ahlbäck IV, six‐month, and 12‐month postoperative groups demonstrated lower values when compared to the Control and Ahlbäck I and II groups. When percentage values were compared to the Control group, mean differences ranged from 7% to 41%. ConclusionPatients with healthy knees or early stage osteoarthritis have higher quadriceps and hamstrings strengths than those with a more advanced stage of the disease, even after knee replacement. These findings suggest that the traditional rehabilitation programs do not recover strength to levels observed in individuals without knee osteoarthritis.

Effect of enzyme replacement therapy on isokinetic strength for all major muscle groups in four patients with Pompe disease—a long-term follow-up

Pompe disease is a rare, inherited metabolic myopathy characterized by progressive weakness of the proximal limb and respiratory muscles. We report the findings from four patients with late-onset Pompe disease treated with α-glucosidase (Myozyme) for 2 (n=2) and 6 (n=2) years, and monitored with isokinetic dynamometry, 6-minute walking test (6MWT), and vital capacity. Patients were evaluated after 6, 12, 24, 36, 48, 60, and 72months. In two patients, muscle size estimated by MRI and DXA scanning was also performed prior to and following 6months of treatment. After 2years of α-glucosidase treatment, maximal isokinetic muscle strength increased by 11% (0%–50%) [median (range)] and 6MWT improved by 18% (2%–40%). In the two patients treated for 6years, the increase in muscle strength stabilized at 40% and 6MWT stabilized at 32%. The improvements primarily occurred during the first 6months of treatment. Interestingly, the weakest muscle groups seemed to benefit more than those less affected, and greater improvements occurred for flexor muscles compared to extensor muscles. Vital capacity did not improve on treatment.

Oral Contraceptives Do Not Affect Muscle Strength and Hop Performance in Active Women

The primary aim of this study was to compare muscle strength in the upper and lower limb, as well as hop performance during oral contraceptive (OC) use with non-OC use in the same woman. A secondary aim was to compare muscle strength and hop performance within 3 specific phases of an OC cycle, as well as during a menstrual cycle of the corresponding cycle days (non-OC cycle). Crossover. Research laboratory. Seventeen moderate to highly recreationally active women participated in the study. Observational study with no intervention. Maximal isokinetic muscle strength of knee extensors, isometric handgrip strength, and 1-leg hop test for distance were measured during 1 OC cycle and 1 non-OC cycle at 3 specific phases, respectively, using a crossover design. No significant differences were found in terms of muscle strength and hop performance between the OC cycle and the non-OC cycle. Furthermore, no significant difference in muscle strength and hop performance could be demonstrated within the OC cycle or within the phases of the menstrual cycle except from maximal isokinetic muscle strength in the knee extensors detected between the early follicular phase and the luteal phase. We found no support for any significant influence of OC use on muscle strength and hop performance in healthy moderately active women.

Experimental knee joint pain during strength training and muscle strength gain in healthy subjects: A randomized controlled trial

Knee joint pain and reduced quadriceps strength are cardinal symptoms in many knee pathologies. In people with painful knee pathologies, quadriceps exercise reduces pain, improves physical function, and increases muscle strength. A general assumption is that pain compromises muscle function and thus may prevent effective rehabilitation. This study evaluated the effects of experimental knee joint pain during quadriceps strength training on muscle strength gain in healthy individuals. Twenty-seven healthy untrained volunteers participated in a randomized controlled trial of quadriceps strengthening (3 times per week for 8 weeks). Participants were randomized to perform resistance training either during pain induced by injections of painful hypertonic saline (pain group, n = 13) or during a nonpainful control condition with injection of isotonic saline (control group, n = 14) into the infrapatellar fat pad. The primary outcome measure was change in maximal isokinetic muscle strength in knee extension/flexion (60, 120, and 180 degrees/second). The group who exercised with pain had a significantly larger improvement in isokinetic muscle strength at all angular velocities of knee extension compared to the control group. In knee flexion there were improvements in isokinetic muscle strength in both groups with no between-group differences. Experimental knee joint pain improved the training-induced gain in muscle strength following 8 weeks of quadriceps training. It remains to be studied whether knee joint pain has a positive effect on strength gain in patients with knee pathology.

Effects of β2-adrenergic stimulation on exercise capacity in normal subjects

β2-Adrenergic receptor agonists are believed to present with ergogenic properties. However, how combined respiratory, cardiovascular and muscular effects of these drugs might affect exercise capacity remain incompletely understood. The effects of salbutamol were investigated in 23 healthy subjects. The study was randomised, placebo-controlled in double-blind and followed a cross-over design. Salbutamol was given at the dose of 10 μg/min in 11 subjects and 20 μg/min iv in the other 12 subjects. Measurements included muscle sympathetic nerve activity (MSNA), ventilatory responses to hyperoxic hypercapnia (7% CO(2) in O(2,) central chemoreflex), isocapnic hypoxia (10% O(2) in N(2), peripheral chemoreflex) and isometric muscle contraction followed by a local circulatory arrest (metaboreflex), cardiopulmonary exercise test (CPET) variables and isokinetic muscle strength. Salbutamol 10 μg/min increased heart rate and blood pressure, while MSNA burst frequency remained unchanged. Peripheral chemosensitivity increased, as evidenced by an increased ventilatory response to hypoxia, but ventilatory responses to hypercapnia or muscle ischaemia remained unchanged. The effects of salbutamol 20 μg/min were similar. Both doses of salbutamol did not affect CPET. Only the higher dose of salbutamol decreased the anaerobic threshold, but this was not associated with a change in VO(2) max. Salbutamol increased the slopes of ventilation as a function of VO(2) (P < 0.05) and VCO(2) (P < 0.001) during CPET. Maximal isokinetic muscle strength was not affected by salbutamol. In conclusion, the acute administration of either low or high dose salbutamol does not affect exercise capacity in normal subjects, in spite of an earlier anaerobic threshold and increased chemosensitivity.

Maximal isokinetic muscle strength in patients with primary hyperparathyroidism before and after parathyroid surgery.

Primary hyperparathyroidism (HPT) is associated with symptoms of generalized fatigue and muscle weakness. The purpose of this study was to investigate muscular function in HPT quantitatively and to evaluate the effect of parathyroid surgery in this respect. The maximal isokinetic muscle strength (peak torque) of knee extension and flexion was measured with a Cybex-II dynamometer in 16 patients with primary HPT (mean serum calcium 2.81 +/- 0.14 mmol/l), four of whom had subjective impairment of strength, and in nine control patients submitted to hemithyroidectomy due to atoxic thyroid adenoma. Before surgery there was no significant difference in muscle strength between the two groups, neither was there any consistent relationship between the subjective feeling of muscular weakness and the measured peak torque. Seven months after surgery the HPT patients had increased their muscle strength by 8 per cent (P less than 0.05). The improvement was correlated with the pre-operative serum calcium levels (r = 0.56, P = 0.02) and was particularly seen in patients with pre-operative subjective muscular weakness. Patients with only slightly raised calcium values and without subjective muscular symptoms did not benefit clearly from surgery, compared with the controls. The study demonstrates that HPT patients, especially those with neuromuscular symptoms, can improve their muscle strength after parathyroid surgery.

Decreased isometric muscle strength after acute hyperglycaemia in Type 1 diabetic patients

Fatigue is a common complaint in diabetic patients during periods of hyperglycaemia. To test whether muscle performance is reduced during acute hyperglycaemia, diabetic patients were studied whilst performing maximal isokinetic and isometric contractions. In this double-blind placebo controlled study, maximal isometric and isokinetic muscle strength was determined in seven Type 1 diabetic patients during normo- and hyperglycaemia using a hyperglycaemic clamp technique. On two separate days, maximal muscle strength of the knee extensors was determined quantitatively using a dynamometer. On both days, muscle strength was determined before a constant blood glucose level was obtained and after the blood glucose level had been kept constant at either 5 or 16 mmol/l for 3 h. Percentage of change from baseline at the two glycaemic levels were calculated and compared. In addition, the changes from baseline at these glycaemic levels were related to glucose turnover. Following hyperglycaemia, a significant decrease in maximal isometric muscle strength was found as compared with normoglycaemia (86 vs. 104% of the initial level) (P = 0.018). In contrast, no alteration of maximal isokinetic muscle strength was found comparing normo- and hyperglycaemia (96 and 95%) (P = 0.74). Changes in muscle strength were not significantly related to either basal or hyperglycaemic glucose turnover. A few hours of hyperglycaemia in Type 1 diabetic patients leads to a reduction of isometric muscle performance, whereas isokinetic muscle strength is unchanged. The reduction in muscle strength could play a role in the development of fatigue and is related more closely to ambient glucose concentrations than to systemic glucose availability.

Efficacy of intraarticular hyaluronic acid in patients with osteoarthritis—a prospective clinical trial

Aim The goal of this study was to determine whether or not the intraarticular administration of hyaluronic acid can improve functional parameters, such as isokinetic muscle strength or total work and clinical test results in patients with osteoarthritis (OA) of the knee.Method As part of a prospective, controlled study 43 patients with osteoarthritic changes of both knees (radiographic Kellgren stage II–III) were followed in a right/left comparison. The influence of intraarticularly injected hyaluronic acid (20mg hyaluronic acid/2ml Hyalart®) on functional and clinical parameters was analysed. We used the isokinetic system Cybex 600 for measuring maximal isokinetic muscle strength and total work. A total of 20 males and 23 females fulfilled the inclusion criteria with an age between 55–78 years and underwent five injections of hyaluronic acid (one injection per week). The injected knee represented the treatment group, while the contralateral knee served as the control.Results The maximum peak torque of the knee extensors in the treatment group was measured between 57±26.15/32.33±19.63Nm prior to the injections and 77.17±32.54/47.83±21.43Nm following the hyaluronic acid therapy (P< 0.01). The analysis of the knee flexors at angular velocities of 60°/s and 180°/s revealed values of 40.44±21.58/22.89±16.64Nm and 53.55±24.26/34.05±17.37Nm (P< 0.01) respectively. The evaluation of the total work of the knee flexors and extensors revealed a significant difference (P< 0.01) between the treatment and control group. The Lequesne score was reduced from 13.57±1.88 prior to the injections to 7.94±2.53 after the treatment (P< 0.01). The pain score was documented with the help of a visual analog scale. The VAS values were reduced at rest from 3.83±1.72cm to 1.36±1.42cm and during weight bearing from 7.57±1.34cm to 3.75±1.32cm in the treatment group (P< 0.01).Conclusions This controlled prospective clinical trial confirmed that 5 weekly intraarticular injections of HA (Hyalart®) in patients with OA of the knee provide pain relief and functional improvements. Copyright 2002 OsteoArthritis Research Society International. Published by Elsevier Science Ltd. All rights reserved.

Determinants and predictors of the maximum walking speed during computer-assisted gait training in hemiparetic stroke patients

Objective: To investigate biomechanical determinants and predictors of walking speed in early gait training after stroke. Design: Prospective. Setting: Physical therapy room of Tohoku University Hospital. Participants: Thirty-four male hemiparetic stroke patients received 8 weeks of computer-assisted gait training (CAGT), which was initiated within approximately 3 months after stroke onset. Main Outcome Measurements: The time and the number of steps required to walk 10m at the fastest possible speed (maximum walking speed [Mws]), the sway path of the center of feet pressure (CFP) in the upright posture, the change in CFP when shifting the body weight either left to right or back and forth, and the maximal isokinetic muscle strength during extension of both knees were measured at the start and at 4 and 8 weeks. Stepwise regression procedures were performed to analyze determinants and predictors of the MWS using the MWS as the dependent variable and personal characteristics, standing balance, and the muscle strength of both knees as the independent variables. Results: The MWS significantly increased from 40.4 to 76.5m/min on average after 8 weeks. The determinant of MWS at the start was the postural control of shifting to the left and right (coefficient of determination of 45.4%). The determinant of MWS at 4 and 8 weeks was the muscle strength during knee extension on the affected side (coefficient of determination of 62.9% and 54.5%, respectively). The predictors of MWS at 4 weeks were the MWS at the start of CAGT, followed by muscle strength during knee extension on the affected side and the time from stroke onset to the start of CAGT (total variance of 84.3%). The predictors at 8 weeks were the MWS at the start, followed by the muscle strength during knee extension on the affected side (total variance of 73.4%). Conclusions: After 4 weeks, the biomechanical determinant of MWS had changed from the postural control of weight-shifting from left to right to the muscle strength during knee extension on the affected side. The MWS at 4 and 8 weeks could be predicted by the initial MWS, the initial muscle strength during knee extension on the affected side, and the time since stroke onset, with high coefficients of determination.

The relationship between the leg muscle strength and physical capacity in patients with rheumatoid arthritis, with reference to the influence of corticosteroids : Danneskiold-Samsøe B, Grimbv G. Clin Rheumatol 1986; 5: 468–474

It has been shown that patients with rheumatoid arthritis have weak muscles, especially when they are treated with corticosteroids. Forty-six female patients suffering from rheumatoid arthritis were evaluated with regard to the physical capacity in the lower legs by measuring the walking speed and the climbing performance as correlated to the isokinetic muscle strength of the knee extensors and the plantar flexors. Twenty-six of the patients (average age 60 years, range 34-76) had been treated with corticosteroids. Twenty patients (average age 58 years, range 31-72) had never received corticosteroids. The mean maximal isokinetic muscle strength of the knee extensors in corticosteroid treated patients was 62 +/- 28 Nm (SD) at the angular velocity 30 degrees/s, and the mean maximal isokinetic muscle strength of the plantar flexors in the same group of patients was 33 +/- 21 Nm (SD) at the same angular velocity. Compared to patients with rheumatoid arthritis who had never been treated with corticosteroids the reduction in muscle strength was 37% and 28%, respectively (p less than 0.001 and p less than 0.01). The mean walking speed in patients with corticosteroid treatment was 0.9 m/s, which was a 36% reduction as compared with that found in patients who had not received corticosteroids (p less than 0.01). Half of the patients who had not received corticosteroids were able to climb a 50 cm step, while this was possible in only 16% of the group of corticosteroid-treated patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Muscle morphology and enzymes in proximal and distal muscle groups of lower limb from patients with corticosteroid treated rheumatoid arthritis: the relationship to maximal isokinetic muscle strength

Abnormal morphological and enzymatic patterns in the lateral vastus muscle have been found in women with corticosteroid treated rheumatoid arthritis. By means of biopsies from the lateral heads of right gastrocnemius muscles, the histology and enzyme activities were compared with those found in right vastus lateralis biopsies. The findings were correlated with isometric and isokinetic strength of the plantar flexors. The relative occurrence of type I fibres in the gastrocnemius muscle was 46.4 +/- 18.7 (SD) %, which is significantly higher than found in the vastus lateralis [35.7 +/- 13.3 (SD) %] (P less than 0.03). The relatively lower percentage of type II fibres in the gastrocnemius muscle was due to a relatively low percentage of type II A fibres [mean 27.9 +/- 16.4 (SD) %] (P less than 0.05). The area of type I fibres in the gastrocnemius muscle was 26.1 X 10(2) +/- 10.0 (SD) micron 2, which is 74% of the mean area for type I fibres found in the vastus lateralis (P less than 0.01). The area of type II fibres in the gastrocnemius was 14.9 X 10(2) +/- 7.1 (SD) micron 2, which is 77% of the mean area for type II fibres found in the vastus lateralis. The isokinetic muscle strength of the plantar flexors in corticosteroid treated patients with rheumatoid arthritis was reduced to less than 50% at all angular velocities when compared with healthy women. The same difference was found in the knee extensors.(ABSTRACT TRUNCATED AT 250 WORDS)