Structural and pathophysiological muscle changes up to one year after post-stroke hemiplegia: a systematic review.

INTRODUCTION: Muscle changes after stroke cannot be explained solely on the basis of corticospinal bundle damage. Muscle-specific changes contribute to limited functional recovery but have been poorly characterized. EVIDENCE ACQUISITION: We conducted a systematic review of muscular changes occurring at the histological, neuromuscular and functional levels during the first year after the onset of post-stroke hemiplegia. A literature search was performed on PubMed, Embase and CINHAL databases up to November 2022 using a keyword combination comprising cerebral stroke, hemiplegic, atrophy, muscle structure, paresis, skeletal muscle fiber type, motor unit, oxidative stress, strength, motor control. EVIDENCE SYNTHESIS: Twenty-seven trial reports were included in the review, out of 12,798 articles screened. Structural modifications described on the paretic side include atrophy, transformation of type II fibers into type I fibers, decrease in fiber diameter and apparent myofilament disorganization from the first week post-stroke up to the fourth month. Reported biochemical changes comprise the abnormal presence of lipid droplets and glycogen granules in the subsarcolemmal region during the first month post-stroke. At the neurophysiological level, studies indicate an early decrease in the number and activity of motor units, correlated with the degree of motor impairment. All these modifications were present to a lesser degree on the non-paretic side. Although only sparse data concerning the subacute stage are available, these changes seem to appear during the first two weeks post-stroke and continue up to the third or fourth month. CONCLUSIONS: Considering these early pathophysiological changes on both the paretic and non-paretic sides, it seems crucial to promptly stimulate central and also peripheral muscular activation after stroke through specific rehabilitation programs focused on the maintenance of muscle capacities associated with neurological recovery or plasticity.

The effect of low back pain on spine kinematics: A systematic review and meta-analysis.

BACKGROUND: Although impairments in dorso-lumbar spine mobility have been previously reported in patients with low back pain, its exact mechanism is not yet clear. Therefore, the purpose of this systematic review and meta-analysis is to investigate and compare spinal kinematics between subjects with and without low back pain and identify appropriate tools to evaluate it. METHODS: The PubMed, Scopus and Web of Science databases were searched for relevant literature. The search strategy was mainly focused on studies investigating lumbar kinematics in subjects with and without low back pain during clinical functional tests, gait, sports and daily functional activities. Papers were selected if at least one of these outputs was reported: lumbar range of motion, lumbar velocity, lumbar acceleration and deceleration, lordosis angle or lumbar excursion. FINDINGS: Among 804 papers, 48 met the review eligibility criteria and 29 were eligible to perform a meta-analysis. Lumbar range of motion was the primary outcome measured. A statistically significant limitation of the lumbar mobility was found in low back pain group in all planes, and in the frontal and transverse planes for thoracic range of motion, but there is no significant limitation for pelvic mobility. The amount of limitation was found to be more important in the lumbar sagittal plane and during challenging functional activities in comparison with simple activities. INTERPRETATION: The findings of this review provide insight into the impact of low back pain on spinal kinematics during specific movements, contributing to our understanding of this relationship and suggesting potential clinical implications.

Reliability of Shear Wave Elastography and Ultrasound Measurement in Children with Unilateral Spastic Cerebral Palsy.

In clinical practice, few data exist on the feasibility of performing reliable shear wave elastography (SWE) and ultrasonography (US) measurements in spastic muscles of children with cerebral palsy (CP). Ten children with unilateral CP took part in SWE and US assessment of the tibialis anterior and medialis gastrocnemius muscles during two sessions separated by a 1-wk interval. Intra- and inter-investigator reliability of shear modulus (µ) and muscle thickness (MT) measurements, at neutral and maximal dorsiflexion angles on both legs, was assessed by two investigators with different levels of experience. Reliability was assessed with the coefficient of variation (CV), standard error of measurement and intra-class correlation coefficient (ICC). Reliability of the µ measurement was insufficient, regardless of angle position (CV >10% and >20% for neutral and maximal dorsiflexion angles, respectively). The intra- and inter-investigator reliability of MT measurements was good (CV >10%, ICC >0.74) for both muscles in both legs. SWE measurements must be performed using a rigorous standardized protocol while MT should be considered an important parameter to monitor change in muscle morphology.

Poststroke Postural Sway Improved by Botulinum Toxin: A Multicenter Randomized Double-blind Controlled Trial.

OBJECTIVE: To assess the effects of injecting botulinum toxin into the lower limb muscles of people with hemiparesis post stroke in terms of their sway areas. DESIGN: A multicenter randomized double-blind trial on the effects of active botulinum toxin treatment vs placebo. SETTING: Clinical examinations and postural sway assessments were performed before botulinum toxin injection and again 4-6 weeks after the injection. PARTICIPANTS: People with hemiparesis with chronic post stroke lower limb spasticity (N=40). INTERVENTIONS: Intramuscular injection of a placebo (physiological serum) was performed on the control group, and botulinum toxin injections were performed on the treatment group. Participants and physical and rehabilitation medicine specialists were given no information as to which of the 2 treatments was applied. MAIN OUTCOME MEASURES: The sway area of the center of pressure was recorded for 30 seconds in 3 conditions: eyes open, eyes open in a dual task (a postural control task combined with an arithmetic task), and eyes closed. Spasticity was measured using the Modified Ashworth Scale. RESULTS: Forty people post stroke were enrolled and randomized into 2 groups, one of which was treated with botulinum toxin (n=19) and the other with placebo (n=21). Spasticity decreased significantly in the treatment group (-0.7, P=.049 in the soleus muscles; -0.8, P=.035 in the gastrocnemii muscles). The sway area did not differ significantly between the 2 groups before treatment. The most conspicuous effect was observed in the case of the dual task, where a significant decrease (P=.005) in the sway area occurred in the treatment group (-3.11±6.92) in comparison with the placebo group (+0.27±3.57). CONCLUSION: Treating spasticity by injecting botulinum toxin into people's lower limb muscles post stroke seems to improve their postural sway. The dual task used here to assess sway seems to be a useful, sensitive test for this purpose.

In-silico pre-clinical trials are made possible by a new simple and comprehensive lumbar belt mechanical model based on the Law of Laplace including support deformation and adhesion effects.

Lower back pain is a major public health problem. Despite claims that lumbar belts change spinal posture due to applied pressure on the trunk, no mechanical model has yet been published to prove this treatment. This paper describes a first model for belt design, based on the one hand on the mechanical properties of the fabrics and the belt geometry, and on the other hand on the trunk geometrical and mechanical description. The model provides the estimation of the pressure applied to the trunk, and a unique indicator of the belt mechanical efficiency is proposed: pressure is integrated into a bending moment characterizing the belt delordosing action on the spine. A first in-silico clinical study of belt efficiency for 15 patients with 2 different belts was conducted. Results are very dependent on the body shape: in the case of high BMI patients, the belt effect is significantly decreased, and can be even inverted, increasing the lordosis. The belt stiffness proportionally increases the pressure applied to the trunk, but the influence of the design itself on the bending moment is clearly outlined. Moreover, the belt/trunk interaction, modeled as sticking contact and the specific way patients lock their belts, dramatically modifies the belt action. Finally, even if further developments and tests are still necessary, the model presented in this paper seems suitable for in-silico pre-clinical trials on real body shapes at a design stage.

Evaluation of the mechanical efficiency of knee braces based on computational modeling.

Knee orthotic devices are commonly prescribed by physicians and medical practitioners for preventive or therapeutic purposes on account of their claimed effect: joint stabilisation and proprioceptive input. However, the force transfer mechanisms of these devices and their level of action remain controversial. The objectives of this work are to characterise the mechanical performance of conventional knee braces regarding their anti-drawer effect using a finite element model of a braced lower limb. A design of experiment approach was used to quantify meaningful mechanical parameters related to the efficiency and discomfort tolerance of braces. Results show that the best tradeoff between efficiency and discomfort tolerance is obtained by adjusting the brace length or the strap tightening. Thanks to this computational analysis, novel brace designs can be evaluated for an optimal mechanical efficiency and a better compliance of the patient with the treatment.

Characterization of a pressure measuring system for the evaluation of medical devices.

The purpose of this study is to evaluate the possible use of four "FSA" thin and flexible resistive pressure mapping systems, designed by Vista Medical (Winnipeg, Manitoba, Canada), for the measurement of interface pressure exerted by lumbar belts onto the trunk. These sensors were originally designed for the measurement of low pressure applied by medical devices on the skin. Two types of tests were performed: standard metrology tests such as linearity, hysteresis, repeatability, reproducibility and drift, and specific tests for this application such as curvature, surface condition and mapping system superposition. The linear regression coefficient is between 0.86 and 0.98; hysteresis is between 6.29% and 9.41%. Measurements are repeatable. The location, time and operator, measurement surface condition and mapping system superposition have a statistically significant influence on the results. A stable measure is verified over the period defined in the calibration procedure, but unacceptable drift is observed afterward. The measurement stays suitable on a curved surface for an applied pressure above 50 mmHg. To conclude, the sensor has acceptable linearity, hysteresis and repeatability. Calibration must be adapted to avoid drift. Moreover, when comparing different measurements with this sensor, the location, the time, the operator and the measurement surface condition should not change; the mapping system must not be superimposed.

Evaluation of the mechanical efficiency of knee orthoses: A combined experimental-numerical approach.

Knee orthotic devices are commonly prescribed by physicians and medical practitioners for preventive or therapeutic purposes with the aim of supporting, aligning or immobilising the joint. However, the evaluation of these devices relies on few biomechanical studies or therapeutic trials and the level of their mechanical actions remain unclear. The objectives of this work are to develop and validate an experimental testing machine regarding its realism as compared to a standardised human limb by using a finite element approach, and then to use this machine to characterise the efficiency of different categories of orthoses under different pathological kinematics and investigate the influence of various design characteristics. It was found that the measured mechanical actions should be corrected to compensate for the rigid design of the test machine. Experimental results showed that the tested orthoses highly differed in their ability to restrain motions and that the stiffening effects of these devices may be able to compensate for deficient internal structures only under low load. Although results remain to be confronted to clinical evidence, this approach paves the way to a standardised procedure for evaluating knee orthoses and developing new designs.

Sensorimotor control deficiency in recurrent anterior shoulder instability assessed with a stabilometric force platform.

BACKGROUND: Deficiencies in both afferent proprioceptive information and efferent motor responses have been independently reported in patients with recurrent anterior shoulder instability. We used a validated force platform method to analyze the association between the stabilometric parameters of the upper limb as representative of the shoulder's sensorimotor control and clinical glenohumeral joint instability. METHODS: We enrolled 32 patients with unilateral recurrent anterior post-traumatic shoulder dislocation, on the dominant side in 13 patients (DIG) and the non-dominant side in 19 patients (NDIG) and 16 healthy nonathletic subjects (CG). Displacements of the Center of Pressure were measured by a Win-Posturo Medicapteurs force platform in the upper limb weight-bearing position with the lower limbs resting on a table up to the anterior superior iliac spines. The association between stabilometric values and clinical shoulder instability was analyzed by side-to-side comparisons and comparisons to a control group. RESULTS: For CG and NDIG, there were no side-to-side differences. For DIG, stabilometric values were significantly higher on the dominant pathological shoulder side than on the healthy contralateral non-dominant side (P < .01). The percentage of side-to-side differences was higher in DIG than CG (P < .01). CONCLUSION: Sensorimotor control deficiency was associated with recurrent anterior shoulder instability, especially in patients with the pathological shoulder on their dominant side. Using a force platform to assess sensorimotor control of the shoulder is feasible in patients with shoulder instability, and can allow assessment of the global sensorimotor control deficiency present in unstable shoulders.

Effects of muscular deficiency on postural and gait capacities in patients with Charcot-Marie-Tooth disease.

OBJECTIVE: The aim of this study was to examine the relationships between lower limb muscular deficiencies and postural and gait capacities. DESIGN: Observational study. SUBJECTS: A total of 26 patients with Charcot-Marie-Tooth disease and 19 health-matched healthy subjects. METHODS: Barefoot gait and postural control were analysed using a walking mat and a force platform, respectively. Muscular strength of the plantar and dorsal ankle flexors were assessed using the Medical Research Council scale. RESULTS: Gait parameters correlated with both dorsal- and plantar-flexors strength, whereas postural parameters correlated only with plantar-flexors strength. More particularly, patients with a weak deficit of the plantar-flexor muscles were characterized by normal postural control except along the antero-posterior axis. For gait control, the overall pattern defined from the gait cycle division was preserved, whereas other spatio-temporal parameters were impaired, and more so in patients with a high level of deficit of the plantar-flexor muscles. CONCLUSION: These data highlight behaviour differences in standardized tasks, such as standing still upright or gait. Improved knowledge of postural and gait capacities may constitute a basis to emphasize the corrections that should be enabled by rehabilitation exercises or orthotic devices.

PRM programmes of care and PRM care pathways: European approach, developments in France.

The development of European Union of Medical Specialists (UEMS) physical and rehabilitation medicine programmes of care (PRMPC) and physical and rehabilitation medicine care pathways (PRMCP) in France is a good example of the positive interaction between European and national organizations. PRMPC were defined at the European level to offer a robust template for the description and assessment of physical and rehabilitation medicine (PRM) clinical activity in various fields and contexts. An accreditation procedure was organized as a peer review. It has started to provide very informative documents. In France, discussions on this topic began in 2000. At the end of the same decade, the European approach fostered the interest of French PRM organizations in a period of negotiating with public authorities about two crucial issues: specifications required for reimbursement of functional instrumental assessments in PRM practice and funding of PRM care in postacute facilities. The French Society of PRM (SOFMER) decided to describe the PRM scope in a systematic way, emphasizing the best balance between patient needs, rehabilitation goals, relevant means and justified funding. Nine 'PRMCP' have been published since 2010 and others are in progress. PRMPC and PRMCP share the same concern about the best response offered by PRM to patients' needs. The first approach is the description of a local organization with respect to both scientific evidence and local conditions. The latter is an outline of PRM intervention related to a multidimensional pattern of patients' situations. Both enhance the role of PRM doctors, whose expertise is necessary for making a synthesis of medical diagnosis and functional assessment, for setting up a patient-centred care strategy and for supervising the rehabilitation team's intervention.

Shoulder sensorimotor control assessment by force platform: feasibility and reliability.

Given the important role of the shoulder sensorimotor system in shoulder stability, its assessment appears of interest. Force platform monitoring of centre of pressure (CoP) in upper-limb weight-bearing positions is of interest as it allows integration of all aspects of shoulder sensorimotor control. This study aimed to determine the feasibility and reliability of shoulder sensorimotor control assessment by force platform. Forty-five healthy subjects performed two sessions of CoP measurement using Win-Posturo(®) Medicapteurs force platform in an upper-limb weight-bearing position with the lower limbs resting on a table to either the anterior superior iliac spines (P1) or upper patellar poles (P2). Four different conditions were tested in each position in random order: eyes open or eyes closed with trunk supported by both hands and eyes open with trunk supported on the dominant or non-dominant side. P1 reliability values were globally moderate to high for CoP length, CoP velocity and CoP standard deviation (SD), standard error of measurement ranged from 6·0% to 26·5%, except for CoP area. P2 reliability values were globally low and not clinically acceptable. Our results suggest that shoulder sensorimotor control assessment by force platform is feasible and has good reliability in upper-limb weight-bearing positions when the lower limbs are resting on a table to the anterior superior iliac spines. CoP length, CoP velocity and CoP SD velocity appear to be the most reliable variables.

Effects of compression stockings on sympathetic activity and heart rate variability in individuals with spinal cord injury.

OBJECTIVE: To investigate whether wearing graduated compression stockings (GCS) could affect the sympatho-adrenergic and heart rate variability (HRV) responses at rest and after a strenuous wheelchair exercise in individuals with spinal cord injury (SCI). DESIGN: Crossover trial. SETTING: Department of Physical Medicine and Rehabilitation, Saint Etienne, France. PARTICIPANTS: Nine men with SCI (five with low paraplegia: LP, four with high paraplegia: HP). INTERVENTIONS: Two maximal wheelchair exercise tests: with and without GCS (21 mmHg). MAIN OUTCOME MEASURES: HRV measurements: high frequency (HF), low frequency (LF), and LF/HF ratio. Norepinephrine (NOR) and epinephrine (EPI), at rest and post-exercise. Secondary measures were: blood pressure, heart rate, maximal power output, oxygen uptake, stroke volume, cardiac output, at rest, during and after exercise. RESULTS: When wearing GCS: LFnu(wavelet-post) significantly increased and HFnu(wavelet-post) significantly decreased (P < 0.05) in SCI subjects, leading to an enhance ratio of LF(wavelet)/HF(wavelet) and a significantly increased in NOR(rest) (P < 0.05). CONCLUSIONS: GCS induces an enhanced sympathetic activity in individuals with paraplegia, regardless of the level of the injury. Enhanced post-exercise sympathetic activity with GCS may help prevent orthostatic hypotension or post-exercise hypotension.

Exercise training improves autonomic profiles in patients with Charcot-Marie-Tooth disease.

INTRODUCTION: The effect of an interval exercise training (ITE) program on heart rate variability (HRV) was studied in 8 patients with Charcot-Marie-Tooth (CMT) disease and 8 healthy controls. METHODS: At baseline, all subjects underwent ambulatory 24-hour Holter electrocardiographic (ECG) monitoring to evaluate HRV. HRV analysis was repeated on CMT patients after they completed a 24-week ITE program on a cycle ergometer. RESULTS: Before exercise, all HRV indices were lower in patients compared with controls, and the difference reached statistical significance for pNN50 (percent of differences between adjacent R-R intervals exceeding 50 ms). After ITE, time- and frequency-domain indices were significantly improved, particularly at night (+8% mean R-R interval, +95% pNN50, 52% reduction in low/high-frequency ratio). We observed significant increases in some of the time and frequency parameters, and values sometimes exceeded those of controls at baseline. CONCLUSIONS: Our results suggest that ITE improves HRV modulation in CMT patients by enhancing parasympathetic activity.

Reliability of isokinetic assessment of shoulder-rotator strength: a systematic review of the effect of position.

CONTEXT: Isokinetic assessment of shoulder internal-(IR) and external-rotator (ER) strength is commonly used with many different postures (sitting, standing, or supine) and shoulder positions (frontal or scapular plane with 45° or 90° of abduction). OBJECTIVE: To conduct a systematic review to determine the influence of position on the intersession reliability of the assessment of IR and ER isokinetic strength, to identify the most reliable position, and to determine which isokinetic variable appears to be most stable in intersession reliability. EVIDENCE ACQUISITION: A systematic literature search through MEDLINE and Pascal Biomed databases was performed in October 2009. Criteria for inclusion were that studies be written in English or French, describe the isokinetic evaluation methods, and describe statistical analysis. EVIDENCE SYNTHESIS: Sixteen studies meeting the inclusion criteria were included. Variable reliability of ER and IR peak torque (PT) were generally reported for all assessment positions; intraclass correlation coefficients were .44-.98 in the seated position with 45° of shoulder abduction, .09-.77 in the seated position with 90° of shoulder abduction, .86-.99 (coefficient of variation: 7.5-29.8%) in the supine position with 90° of shoulder abduction, .82-.84 in the supine position with 45° of shoulder abduction, and .75-.94 in standing. The ER:IR ratio reliability was low for all positions. CONCLUSIONS: The seated position with 45° of shoulder abduction in the scapular plane seemed the most reliable for IR and ER strength assessment. The standing position or a shoulder posture with 90° of shoulder abduction or in the frontal plane must be used with caution given the low reliability for peak torque. Good reliability of ER and IR PT was generally reported, but ER:IR ratio reliability was low.

Assessment of appropriate ankle-foot orthoses models for patients with Charcot-Marie-Tooth disease.

OBJECTIVE: : The purpose of this study was to demonstrate to what extent ankle-foot orthoses improve posture and gait control in patients with Charcot-Marie-Tooth disease and to identify the most appropriate characteristics of ankle-foot orthoses for patients regarding their clinical characteristics. DESIGN: : Twenty-six Charcot-Marie-Tooth patients were recruited. Clinical data (such as levels of sensory and muscular deficits) and posture and gait capacities were collected in three randomized experimental conditions (wearing ordinary shoes or with plastic and elastic orthoses). Several subgroups of patients, constituted using predictive value analysis, were associated using the probabilities of enhancing posture and gait control while wearing the various models of orthoses. RESULTS: : Compared with ordinary shoes alone, adding plastic ankle-foot orthoses partially improved both gait and posture control, whereas wearing elastic orthoses only partially affected the more dynamic gait control. Furthermore, the choice between the two models can be clarified by taking into account distal lower limb muscle capacity. CONCLUSIONS: : Ankle-foot orthosis prescription appears relevant for improving balance and gait performance in Charcot-Marie-Tooth patients, particularly when the model adequately compensates for specific muscle deficits. This study also provides objective arguments for making adequate bracing.

Rotator cuff strength in recurrent anterior shoulder instability.

BACKGROUND: Although rotator-cuff muscle contraction plays an important role in stabilizing the glenohumeral joint, little is known about the role of these muscles in the pathophysiology of recurrent anterior instability. We intended to analyze the association between isokinetic internal rotator and external rotator muscle strength and glenohumeral joint instability in patients with recurrent anterior instability that was not previously treated surgically. METHODS: We enrolled thirty-seven patients with unilateral recurrent anterior posttraumatic shoulder dislocation and eleven healthy nonathletic subjects in this controlled study. The association between internal rotator and external rotator strength and shoulder instability was analyzed by side-to-side comparisons and comparisons with a control group. Isokinetic internal rotator and external rotator strength was evaluated with a Con-Trex dynamometer, with the subject seated and the shoulder abducted 45° in the scapular plane. Tests were performed at 180°/s, 120°/s, and 60°/s in concentric mode for both sides. Peak torque normalized to body weight and external rotator to internal rotator ratio were calculated for each angular velocity. Clinical and isokinetic evaluation was done by the same rehabilitation physician. RESULTS: The association between shoulder instability and internal rotator and external rotator strength was associated with side-to-side differences (p < 0.05). Compared with a control group, strength values were lower on the pathological shoulder side of the patients with shoulder instability than on the healthy contralateral shoulder of control subjects at 180°/s and 120°/s (p < 0.05). The side-to-side differences were increased when the nondominant upper-extremity side was involved and were decreased when the dominant side was involved. There was no association between glenohumeral joint instability and external rotator to internal rotator ratio. CONCLUSIONS: Internal rotator and external rotator weakness was associated with recurrent anterior instability, and side-to-side differences depended on the side of hand dominance. Use of a control group may help in the analysis of the influence of constraints on shoulder strength. Further prospective studies are necessary to determine whether the weakness is a cause or an effect of the instability.

Effects of compression stockings during exercise and recovery on blood lactate kinetics.

This study aimed to investigate if wearing compression stockings (CS) during exercise and recovery could affect lactate profile in sportsmen. Eight young healthy trained male subjects performed two maximal exercise tests on a cycle ergometer on two different occasions performed randomly: CS during both exercise and recovery, and no CS. Blood lactate concentration was taken during exercise and at 0, 3, 5, 10, 15, 30 and 60 min post-exercise. The individual blood lactate recovery curves were fitted to a biexponential time function: La(t) = La(0) + A1(1 - e(-gamma1t)) + A2(1 - e(-gamma2t)), where gamma(1) and gamma(2) denote the abilities to exchange lactate between the previously active muscles and the blood and to remove lactate from the organism, respectively. A significantly higher blood lactate value at the end of the maximal exercise was found (12.1 +/- 0.5 vs. 10.8 +/- 0.5 mmol l(-1)) wearing CS as compared to no CS (P < 0.05). Lower gamma(1) and higher gamma(2) values were observed with CS during recovery, as compared to no CS. It was concluded that CS during graded exercise leads to a significant higher blood lactate value at exhaustion. Since lactate exchanges were expected to be decreased during exercise due to CS, this result was likely attributable to a higher lactate accumulation related to a greater overall contribution of anaerobic glycolysis. Although the lactate removal ability was significantly improved when wearing CS during recovery, its efficacy in promoting blood lactate clearance after high-intensity exercise is limited.