The influence of prednisone on the muscle morphology and muscle enzymes in patients with rheumatoid arthritis

Thirty-five female patients, mean age 63 years, suffering from rheumatoid arthritis participated the study. Twenty patients had been on long-term low-dose corticosteroid treatment. Fifteen patients had never received corticosteroids. A control group of 15 age- and sex-matched healthy subjects was also studied. Examination of muscle biopsies from the (right) vastus lateralis and measurements of isokinetic and isometric knee-extension muscle strength were performed in all subjects. Rheumatoid arthritis patients treated with corticosteroid showed a low percentage of type I fibres, mean 35.7 (range 17-66) % compared with patients who did not receive corticosteroid (P less than 0.005). The latter group did not differ from the controls. The muscle fibre areas also were affected in the corticosteroid treated rheumatoid patients. Type I and type II mean fibre areas were reduced by 32% and 50%, respectively, when compared with non-prednisone treated patients. The latter group did not differ from the controls in this respect. A correlation was found between the isokinetic muscle strength of the knee extensors and the mean areas of type I and type II in patients treated with prednisone (r = 0.48, P less than 0.05 and r = 0.58, P less than 0.02 respectively). No such correlation was found when using isometric measurements of the knee extensors. A positive correlation was found in both groups of rheumatoid arthritis patients between the areas of the type I and type II fibres (r = 0.66 - 0.68, P less than 0.05 - 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)     

Tendon properties and muscle architecture for knee extensors and plantar flexors in boys and men

Background

The purpose of this study was to compare the elastic properties and size of tendinous structures and muscle architecture for knee extensors and plantar flexors in boys and men.

Methods

Twenty-two early pubescent boys (9.6–12.7 yrs) and 23 young adult men (19.8–26.2 yrs) participated in this study. The maximal strain and thickness of tendinous structures for knee extensors and plantar flexors were measured using ultrasonography. In addition, the fascicle lengths of vastus lateralis and medial gastrocnemius muscles were measured.

Findings

The maximal strain of tendinous structures for plantar flexors was significantly greater in boys than in men, while there was no difference in the maximal strain for knee extensors between the two groups. The relative thickness (to body mass^1/3) of Achilles tendon was significantly greater in boys than in men, although there was no difference in that of patellar tendon between the two groups. The relative fascicle length (to limb length) of vastus lateralis muscle was significantly lower in boys than in men, although there was no difference in that of medial gastrocnemius muscle between the two groups.

Interpretation

These results suggest that the amount of changes in the elastic properties and sizes of tendinous structures and in the fascicle lengths from early pubescence to maturity is different for different muscle groups (in particular, the knee extensors and the plantar flexors).     

Relationship between muscle morphology and metabolism in obese women: the effects of long-term physical training

To evaluate the relationships between changes in muscle morphology and metabolic adaptation to physical training in obesity, twenty obese women were subjected to a physical training programme with three sessions a week for 3 months. Physical training resulted in lowering of plasma insulin and improved glucose tolerance. Neither body weight nor body fat changed. With physical training the percentage distribution of fast twitch oxidative (FTa) muscle fibres (m vastus lateralis) increased (from 30.3 +/- 5.1% to 35.2 +/- 4.8%, P less than 0.05) and that of fast twitch glycolytic fibres decreased (from 18.3 +/- 6.6 to 5.8 +/- 4.8%, P less than 0.05). The number of capillaries increased, mainly around slow twitch (ST) fibres (from 4.5 +/- 0.6 to 5.8 +/- 0.8, P less than 0.01) and fast twitch oxidative (FTa) fibres (from 3.9 +/- 0.7 to 4.7 +/- 0.8, P less than 0.01). The activities of oxidative enzymes (cytochrome-c-oxidase and citrate synthase) increased (P less than 0.05) while those of glycolytic enzymes (phosphofructokinase and hexokinase) decreased after physical training (P less than 0.01). Significant negative correlations between plasma insulin and number of capillaries in contact with ST fibres (r = 0.80, P less than 0.001) and FTa fibres (r = 0.62, P less than 0.001) were found before training. The capillary density around those fibres could predict 80% of the explained variance of plasma insulin levels (P less than 0.001). The changes of glucose concentration after training could be predicted by observed changes in enzyme activities. The strong associations between muscle morphology and capillarization and enzyme activities and glucose and insulin concentrations and their changes after training suggest an important regulatory role of muscle which warrants further studies.     

The influence of functional electrical stimulation on the properties of vastus lateralis fibres following total knee arthroplasty.

The influence of functional electrical muscle stimulation (FES) on selected properties of vastus lateralis muscle fibres was studied in patients recovering from total knee arthroplasty for osteoarthritis. Prior to surgery, on the average, muscle biopsies from the vastus lateralis could be characterized as having a predominance of Type I fibres which were significantly larger in cross-sectional area than the Type II fibres in the same sample. Following surgery, muscle biopsies from a group of patients (n = 7) which received continuous passive motion and no FES, exhibited a marked increase in the proportion of Type II fibres along with a general atrophy of both the Type I and Type II fibres. Patients receiving passive motion and FES (n = 9) also showed an increase in the relative percentage of Type II fibres. Post-operatively, however, there was no significant reduction in fibre area in the stimulated muscles. These data suggest that FES was effective in attenuating the muscle atrophy associated with total knee arthroplasty but had no influence on those metabolic properties which were related to muscle fibre type classification criteria.     

Physical training in elderly men with special reference to quadriceps muscle strength and morphology

Summary. Physical training, including strength training of the lower extremities, was performed three times per week for 12 weeks by twelve 69–74-year-old men with no cardiovascular or locomotor symptoms. Only body weight was used as resistance. The training was considered to be moderately intense for this age-group. After training, the heart rate was significantly lower at submaximal loads, demonstrating a conditioning effect of the training programme. The static and dynamic (isokinetic) muscle strength in the quadriceps muscle increased significantly with the training. Muscle biopsies were obtained from the vastus lateralis muscle for fibre, capillary and enzyme activity analysis. The fibre composition was altered after training, with a significantly higher proportion of Type II fibres, mainly due to an increase of Type II A fibres. The relative area of the Type IIA fibres increased significantly with training. There was no change in total body cell mass or capillarization. There was also enzymatic evidence of training adaptation, with a significant increment in myokinase activity. It is concluded that the ageing human skeletal muscle remains trainable and that the training response is similar to that seen in younger age-groups.     

Effect of hyperthyroidism on fibre-type composition,fibre area,glycogen content and enzyme activity in human skeletal muscle

Summary. Seven hyperthyroid patients were studied by repeated muscle biopsies (vastus lateralis) before and after a period of medical treatment which averaged 10 months. The biopsies were analysed with regard to fibre-type composition, fibre area, capillary density, glycogen content and enzyme activities representing the glycolytic capacity (hexokinase, 6-phosphofructokinase), oxidative capacity (oxoglutarate dehydrogenase, citrate synthase) and Ca²⁺- and Mg²⁺-stimulated ATPase in muscle. In the pretreatment biopsy (hyperthyroid state), there was a significantly lower proportion of type I fibres (30% vs. 41%), a higher capillary density (23%), lower glycogen content (33%), and higher hexokinase activity (32%) compared with the post-treatment biopsy. No significant changes in the activity of the remaining enzymes were observed. The present study indicates that hyperthyroidism induces a transformation from type I to type II fibres in human skeletal muscle. The increase in hexokinase activity probably reflects a higher glucose utilization by skeletal muscle in order to compensate partially for the reduced glycogen content.     

Assessment of skeletal muscle fatigue in men with coronary artery disease using surface electromyography during isometric contraction of quadriceps muscles

OBJECTIVE: To evaluate whether using surface electromyography to assess skeletal muscle fatigue during an isometric exercise has the potential to be clinically useful in patients with coronary artery disease (CAD). DESIGN: Double sample comparative study. SETTING: Cardiac rehabilitation service in France. PARTICIPANTS: Sixteen men with documented CAD and 9 age-matched healthy men. INTERVENTIONS: Assessment of quadriceps skeletal muscle fatigue on an isokinetic apparatus with surface electromyography measurements and a symptom-limited exercise test in a laboratory. MAIN OUTCOME MEASURES: The maximal voluntary isometric force (MVIF) of the quadriceps was quantified as a measure of muscle strength and isometric endurance was defined as the time required to sustain a contraction at 50% of MVIF until exhaustion. Surface electromyography signals were recorded from the vastus lateralis, rectus femoris, and vastus medialis during isometric endurance. The root mean square (RMS) and the median frequency (MF) were directly calculated on a computer and then normalized (as a percentage of the initial value). RESULTS: Muscle strength did not differ significantly between the patients with CAD and the healthy subjects (229+/-21N/m vs 228+/-52N/m), but isometric endurance was reduced (64+/-17s vs 90+/-7s, P <.01). The RMS values showed a significantly higher increase in the healthy subjects versus the patients with CAD for the vastus lateralis and vastus medialis ( P <.001). The MF values were significantly lower for the vastus lateralis, rectus femoris ( P <.01), and vastus medialis ( P <.05) in patients with CAD compared with the healthy subjects. CONCLUSIONS: Skeletal muscle fatigue occurs sooner in men with CAD relative to matched healthy men, despite similar muscle strength. This finding may be the result of an abnormality of skeletal muscle function and may play an important role in measuring functional capacity. In addition, it may be a useful tool to assess the efficacy of cardiac rehabilitation interventions.     

The relationship of lower-extremity muscle torque to locomotor performance in people with stroke

BACKGROUND AND PURPOSE: Improved walking is a common goal after stroke. The purpose of this study was to examine the relationship between the torque generated by the muscles of both lower extremities and 2 locomotor tasks: gait on level surfaces and stair climbing in people who had strokes. SUBJECTS: Twenty community-dwelling individuals (mean age=61.2 years, SD=8.4, range=52-82) who had strokes and who were able to walk independently participated in the study. The mean time since stroke was 4.0 years (SD=2.6, range=1.5-10.0). METHODS: Pearson correlations and multiple regression were used to measure the relationship between concentric isokinetic torque of the flexor and extensor muscles of the hip, knee, and ankle bilaterally and locomotor performance (gait on level surfaces and stair-climbing speed). RESULTS: The isokinetic torques of the paretic ankle plantar flexors, hip flexors, and knee flexors had moderate to high correlations (r=.5-.8) with gait and stair-climbing speeds. Muscle force could explain 66% to 72% of the variability in gait and stair-climbing speeds. Correlations for the nonparetic side were as high as or higher than those for the paretic side for some muscle groups. DISCUSSION AND CONCLUSION: Muscle performance measurements of both limbs should be included in the evaluation of locomotion and treatment of people following a stroke.     

A simple and rapid method for the determination of the concentrations of magnesium, sodium, potassium and sodium, potassium pumps in human skeletal muscle

1. For the diagnosis of electrolyte disorders, data on skeletal muscle composition are often valuable, but rarely available. We have therefore developed a simple and rapid needle biopsy procedure for the determination of the concentrations of K+, Na+, Mg2+ and Na+, K+-pumps in muscle. 2. Using a Bergstr?m needle, biopsies weighing around 25 mg were taken from the vastus lateralis muscle of 18 normal subjects (aged 44-86 years) and extracted with trichloroacetic acid (TCA). The concentrations of K+, Na+ and Mg2+ were 90.7 +/- 1.8, 31.9 +/- 1.6 and 9.5 +/- 0.2 mumol/g wet wt., respectively (means +/- SE). 3. The TCA extraction gave the same values as digestion with 65% HNO3 or 35% H2O2, could be used over the weight range 10-55 mg and showed a Mg2+ recovery of 101.7%. 4. The concentration of Na+, K+-pumps was quantified as the total capacity for [3H]ouabain binding. In vastus lateralis biopsies obtained from six normal subjects the mean value was 258 +/- 16 pmol/g wet wt. 5. Comparison of the concentrations of K+, Mg2+ and [3H]ouabain-binding sites in samples obtained post mortem showed modest variation among different muscles with varying fibre composition. 6. Measurements of the concentrations of K+, Na+, Mg2+ and Na+, K+-pumps in duplicate biopsies of the vastus lateralis yield values which seen representative for the total pool of skeletal muscle fibres and can be performed within a few hours.(ABSTRACT TRUNCATED AT 250 WORDS)     

Repeatability of fibre type and enzyme activity measurements in human skeletal muscle

Summary. In order to assess the variability in repeated determination of human muscle fibre type distribution, fibre area and enzyme activity measurements, two biopsies were taken within 10 days in the same vastus lateralis for 12 females and 13 males, and in the right and in the left muscles for 25 other subjects (13 females and 12 males). Within muscle, intraclass reliability coefficients were 0·88, 0·82 and 0·56 for type I, IIa and IIb per cent fibres, respectively, and ranged from 0·74 to 0·82 for fibre areas and from 0·71 to 0·90 for enzyme markers of different metabolic pathways. Correlations between right and left muscle measurements were also high for fibre areas (from 0·85 to 0·91) and enzyme activities (from 0·71 to 0·87), except for phosphofructokinase (r=0·63). In contrast, the right and left thigh muscle correlation reached 0·67, 0·40 and 0·64 for type I, IIa and IIb fibre distribution, respectively. Thus, the variation in muscle sampling and technical procedures reached about 15% of the total variation (i.e. total differences between subjects) for the proportion of fibre type I and IIa and about 20–25% for fibre areas and enzyme activities. On the other hand, the technical error for the proportion of fibre type I and IIa is about 6–7%. This implies that differences brought about by any experimental treatment on these skeletal muscle characteristics in human studies have to be of a relatively large magnitude before being detectable. On the other hand, fibre areas and enzyme activities measured in single needle biopsy sample, from one of the vastus lateralis muscles, are quite representative of the other vastus lateralis. Similarity in fibre type proportion between right and left vastus lateralis cannot be postulated, however, without investigating both muscles.     

Effects of high resistance training in patients with myotonic dystrophy

Nine ambulatory subjects with myotonic dystrophy participated in a supervised 12-week progressive high-resistance training program. Knee extensor muscles were trained 3 times a week with free weights, 3 x 10 repetitions at 80% of 1RM. One leg was randomly chosen for training and the other served as control. Six patients completed the training program. In the trained leg, 1RM increased from 16.4 +/- 3.4 kg to 21.8 +/- 2.6 kg (p = 0.0002). There was no difference between pre- and post-training concentric or eccentric isokinetic values at 30 degrees/second in either leg. Muscle biopsy from m. vastus lateralis in the trained leg revealed no systematic difference in the degree of histopathological abnormalities before and after training. After training, there was a tendency toward increase in cross-sectional area of type I muscle fibres. However, the number of subjects was too small to draw conclusions regarding the effects of training on the histopathological changes. Magnetic resonance imaging revealed no difference in the m. quadriceps area after training. In conclusion, patients with myotonic dystrophy improved their muscle strength without any observed negative side effects after a 12-week high-resistance training program.     

Variability in muscle fibre areas in whole human quadriceps muscle: how to reduce sampling errors in biopsy techniques

Summary. A single biopsy is a poor estimator of the muscle fibre cross-sectional area (CSA) for a whole human muscle because of the large variability in the fibre area within a muscle. To determine how the sampling errors in biopsy techniques can be reduced, data on the CSA of type 1 and type 2 fibres obtained from cross-sections of whole vastus lateralis muscle of young men, have been analysed statistically. To obtain a good estimate of the mean fibre CSA in a biopsy, measuring all fibres in that biopsy gives the best result. To obtain a good estimate of the mean fibre CSA for a whole muscle, the number of biopsies has a much greater influence on the sampling error than the number of fibres measured in each biopsy, but the number of biopsies needed to obtain a given sampling error can vary by a factor of two. If the fibre CSA in three or more biopsies is measured, it is sufficient to measure only 25 fibres in each biopsy. If less than three biopsies are taken, there is no worthwhile reduction in sampling error when more than 100 fibres are measured. To determine the mean fibre CSA for a whole group of individuals, our preference is to maximize the number of individuals, and only take single biopsies. In conclusion, to determine the mean fibre CSA for this particular muscle with a certain precision, we suggest analysis of three biopsies, taken from different depths of the muscle, and measurement of 25 fibres in each biopsy.     

Patellar kinematics, part I: the influence of vastus muscle activity in subjects with and without patellofemoral pain

BACKGROUND AND PURPOSE: Reduced motor unit activity of the vastus medialis muscle relative to the vastus lateralis muscle has been implicated as a cause of lateral patellar subluxation. The purpose of this study was to assess the influence of vastus muscle motor unit activity on patellar kinematics. SUBJECTS: Twenty-three women (mean age=26.8 years, SD=8.5, range=14-46) with a diagnosis of patellofemoral pain and 12 women (mean age=29.1 years, SD=5.0, range=24-38) without patellofemoral pain participated. Only female subjects were studied because of potential biomechanical differences between sexes. METHODS: Patellar kinematics (kinematic magnetic resonance imaging) and vastus muscle electromyographic (EMG) activity using indwelling electrodes were measured during resisted knee extension. Measurements of medial and lateral patellar displacement and tilt obtained from magnetic resonance images were correlated with normalized vastus lateralis:vastus medialis oblique muscle and vastus lateralis:vastus medialis longus muscle EMG ratios at 45, 36, 27, 18, 9, and 0 degrees of knee flexion using a stepwise regression procedure. RESULTS: The vastus lateralis:vastus medialis longus muscle EMG ratio contributed to the prediction of lateral patellar glide at 27 degrees of knee flexion (r=-.48), with increased vastus medialis longus muscle activity being associated with greater lateral patellar displacement. A similar inverse relationship was evident with lateral patellar tilt at 36, 27, 18, and 9 degrees of knee flexion. CONCLUSION AND DISCUSSION: These results suggest that increased motor unit activity of the vastus medialis muscle appears to be associated with abnormal patellar kinematics in women, but it is not necessarily a cause of abnormal patellar kinematics.     

Reliability and validity of panoramic ultrasound for muscle quantification

This study examined the reliability and validity of using customized templates to acquire panoramic ultrasound (US) images for determining cross-sectional area (CSA) and volume in the vastus lateralis (VL), rectus femoris (RF), medial gastrocnemius (MG) and lateral gastrocnemius (LG). Panoramic US and magnetic resonance imaging (MRI) images were analyzed by two trained investigators. The inter-experimenter reliability (coefficient of variation [CV]) of panoramic US ranged from 2.4% to 4.1% and the intraclass correlation (ICC) ranged from 0.963 to 0.991, whereas the inter-experimenter CV of MRI ranged from 2.8% to 3.8% and the ICC from 0.946 to 0.986. Bland-Altman plots demonstrated high agreement between US and MRI; however, values obtained from MRI were systematically larger than those obtained from US. The present results indicate that using a customized US template provides reliable measures of leg muscle CSA and, thus, could be used to characterize muscle CSA and volume.     

Vastus lateralis oxygenation and blood volume measured by near-infrared spectroscopy during whole body vibration

The purpose of this study was to investigate the effects of whole body vibration (WBV) on oxygenation of vastus lateralis muscle during squatting exercise. Eighteen male subjects [mean age, 27.3 +/- 6.0 (SD) years; mean height, 171.8 +/- 4.9 cm; mean weight, 64.4 +/- 6.1 kg] performed squatting exercise on a vibration platform for 3 min with and without vibration, and changes in oxygenation of the vastus lateralis muscle were determined by near-infrared spectroscopy. The muscle oxygenation levels and total haemoglobin and myoglobin levels (total Hb/Mb) decreased during squatting exercise with and without vibration. After exercise, the muscle oxygenation level and total Hb/Mb rapidly increased from the minimum value during exercise and remained constant for latter 10 min. The muscle oxygenation levels with vibration from 90 to 180 s after the start of squatting exercise were significantly lower than those without vibration. Total Hb/Mb with vibration from 90 s after the squatting exercise to 540 s were significantly higher than those without vibration. This study demonstrated that WBV exercise affects the oxygenation level of vastus lateralis muscle and reduces muscle oxygenation level compared to that with no WBV. Therefore, WBV exercise may be an efficient training stimulus for muscle deoxygenation.     

Altered hamstring-quadriceps muscle balance in patients with knee osteoarthritis

BACKGROUND: To compare hamstring to quadriceps muscle coactivity during level walking, stair ascent, and stair decent between individuals with and without knee osteoarthritis. METHODS: In a cross-sectional study, subjects with grade II knee osteoarthritis (n = 26), healthy age- and gender-matched (n = 20) and healthy, young adults (n = 20) performed three activities of daily living. During the stance phase of these activities surface electromyography was measured. Two coactivity ratios were computed, the biceps femoris to vastus lateralis ratio and the ratio of the biceps femoris EMG activity relative to the EMG activity measured during contraction- and velocity-specific maximal voluntary biceps femoris contraction, i.e., biceps femoris to maximal biceps femoris activity. FINDINGS: Subjects with knee osteoarthritis had significantly higher coactivity than age-matched healthy adults and young adults and healthy adults had more coactivity than young adults regardless the type of coactivity ratio. The biceps femoris to vastus lateralis ratio yielded 25% higher coactivity value than the biceps femoris to maximal biceps femoris ratio (P < 0.0001). The EMG activity of the vastus lateralis relative to maximal vastus lateralis EMG activity was 92% in subjects with knee osteoarthritis, 57% in age-matched controls, and 47% in young adults (P < 0.0001). INTERPRETATION: Patients with knee osteoarthritis revealed increased hamstring muscle activation while executing activities of daily living. Altered muscle activation at the knee may interfere with normal load distribution in the knee and facilitate disease progression. Therapeutic interventions should focus not only on quadriceps strengthening but also on improving muscle balance at the knee.     

Decrease in human quadriceps muscle protein turnover consequent upon leg immobilization

Quadriceps muscle protein turnover was assessed in the post-absorptive state in six men immediately after the end of unilateral leg immobilization (37 +/- 4 days) in a plaster cast after tibial fracture. A primed-constant intravenous infusion of L-[1-13C]leucine was administered over 7 h. Quadriceps needle biopsies, taken bilaterally at the end of the infusion, were analysed for muscle protein leucine enrichment with 13C. Quadriceps muscle protein synthetic rate, calculated from the fractional incorporation of [13C]leucine into protein compared with the average enrichment of blood alpha-ketoisocaproate, was 0.046 +/- 0.012%/h in the uninjured leg, but was only 0.034 +/- 0.007%/h in the quadriceps of the previously fractured leg (P less than 0.05, means +/- SD). Muscle RNA activity (i.e. protein synthetic rate per RNA) fell from 0.27 +/- 0.08 microgram of protein synthesized h-1 microgram-1 of RNA in the control leg to 0.14 +/- 0.03 microgram of protein synthesized h-1 microgram-1 of RNA in the immobilized leg (P less than 0.02). Immobilization was associated with a significant atrophy of type I muscle fibres (mean diameter 69.5 +/- 21 microns immobilized, 81.1 +/- 18 microns control, P less than 0.05), but no significant change occurred in type II fibre diameter. Mean quadriceps fibre volume calculated from the values for fibre diameter and percentage of each fibre type, was smaller in the injured leg by 10.6%; this value was near to the calculated difference in muscle thigh volume (calculated from thigh circumference and skin-fold thickness) which was less by 8.3%.(ABSTRACT TRUNCATED AT 250 WORDS)     

One session of whole body vibration increases voluntary muscle strength transiently in patients with stroke

OBJECTIVE: To determine the effect of whole body vibration on isometric and eccentric torque and electromyography (EMG) variables of knee extensors on the affected side of stroke patients. DESIGN: A randomized controlled study. SETTING: A rehabilitation centre. SUBJECTS: Sixteen patients (age 58.2+/-9.4 years) were enrolled in an inpatient rehabilitation programme 27.2+/-10.4 days after a stroke. INTERVENTIONS: Eight patients were randomly assigned to the vibration group and received 20 Hz vibration (5 mm amplitude) while standing on a vibration platform for 1 minute six times in one session. Patients in the control group also stood on the platform but did not receive vibration. MAIN MEASURES: Maximum isometric and eccentric torque, rate of torque development, root-mean-squared EMG, median frequency of vastus lateralis, and co-activation of knee flexors. RESULTS: Isometric and eccentric knee extension torque increased 36.6% and 22.2%, respectively, after vibration (P<0.05) and 8.4% and 5.3% in the control group. Vibration increased EMG amplitude 44.9% and the median frequency in the vastus lateralis by 13.1% (all P<0.05) without changes in the control group (10.6% and 3.9%). Vibration improved the ability to generate mechanical work during eccentric contraction (17.5%). Vibration reduced biceps femoris co-activation during isometric (8.4%, ns) and eccentric (22.5%, P<0.05) contraction. CONCLUSION: These results suggest that one bout of whole body vibration can transiently increase voluntary force and muscle activation of the quadriceps muscle affected by a stroke.     

Impact of a rehabilitation program on muscular strength and endurance in peripheral arterial occlusive disease patients

Rehabilitation care and physical exercise are known to constitute an effective treatment for chronic peripheral arterial occlusive disease (PAOD) at the intermittent claudication (IC) stage. Improvements in functional capacities and quality of life have been reported in the literature. We decided to assess the effects of hospital-based exercise training on muscle strength and endurance for the ankle plantar and dorsal flexors in this pathology.Patients and methodsThis prospective study included 31 subjects with chronic peripheral arterial occlusive disease (PAOD) and IC who followed a 4-week rehabilitation program featuring walking sessions, selective muscle strengthening, general physical exercise and therapeutic patient education. An isokinetic assessment of ankle plantar and dorsal flexors strength was conducted on the first and last days of the program. We also studied the concentric contractions at the angular velocity of 30°/s and 120°/s for muscle strength and at 180°/s for muscle fatigue. We also measured the walking distance for each patient.ResultsWalking distance improved by 246%. At baseline, the isokinetic assessment revealed severe muscle weakness (mainly of the plantar flexors). The only isokinetic parameter that improved during the rehabilitation program was the peak torque for plantar flexors at 120°/s.ConclusionAll patients presented with severe weakness and fatigability of the ankle plantar and dorsal flexors. Our program dramatically improved walking distance but not muscle strength and endurance.