Healthy vs. osteoarthritic hips: a comparison of hip, pelvis and femoral parameters and relationships using the EOS® system.

BACKGROUND: Osteoarthritis is a debilitating disease, for which the development path is unknown. Hip, pelvis and femoral morphological and positional parameters relate either to individual differences or to changes in the disease state, both of which should be taken into account when diagnosing and treating patients. These have not yet been comprehensively quantified. Previous imaging studies have been limited by a number of factors: supine rather than standing measurements; high radiation dose; a limited field of view; and 2D rather than 3D measurements. EOS®, a new radiographic imaging modality that acquires simultaneous frontal and lateral (sagittal) X-ray images of the full body, allows 3D reconstruction of the hip, pelvis and lower limb. The aim of the study was to explore similarities and differences between healthy and osteoarthritis groups. METHODS: Two groups of subjects, 30 healthy and 30 with hip osteoarthritis, were assessed and compared for pelvic, acetabular and femoral parameters in the standing position. FINDINGS: There were not only significant differences between groups but also considerable overlap amongst the individuals. Sacral slope, acetabular angle of Idelberger and Frank, femoral mechanical angle and femoral head eccentricity as well as right-left asymmetries in centre-edge acetabular angle and femoral head diameter were higher on average in osteoarthritic patients compared to healthy subjects, whereas acetabular abduction was lower in the osteoarthritic group (P<0.05). Correlations were identified between key parameters in both groups. INTERPRETATION: Differences between the groups suggest either degenerative changes over time or inherent differences between individuals that may contribute to the disease progression. These data provide a basis for longitudinal and post-surgery studies. Due to the considerable variability amongst individuals and the considerable overlap between groups, patients should be evaluated individually and at multiple joints when planning hip, knee and spine surgery.

Posture and gait abilities in patients with myotonic dystrophy (Steinert disease). Evaluation on the short-term of a rehabilitation program.

OBJECTIVES: To evaluate the effects of a rehabilitation program in terms of balance, gait and muscle strength in a population of patients with myotonic dystrophy. PATIENTS: Twenty patients benefited, as outpatients in a hospital setting, from a rehabilitation program with clinical and instrumental evaluations. The evaluation focused on quantitative balance measurement by clinical and stabilometer tests, gait assessed by Locometre and extensors and flexors knee muscle strength measured in isokinetic concentric mode at 60°/s. RESULTS: After the rehabilitation program, we observed a significant improvement in the patients' balance capacities measured with the Berg Balance Scale (BBS), fast gait speed and muscle strength. However, the instrumental evaluation did not report any gains for static balance and spontaneous gait speed after the training program. No correlation was found between the various improvements. CONCLUSION: A rehabilitation program focused on strength, gait and balance allowed for significant improvements in some parameters of myotonic dystrophy. These results attest to the relevance of a short-term rehabilitation protocol for these patients in the framework of a multidisciplinary therapeutic care. The disparity observed in the results measured for these patients suggest the contribution of cognitive involvement in the limitations felt by patients with myotonic dystrophy in the areas of gait and balance.

Does somatosensory loss induce adaptation of the gait initiation process?

Gait initiation (GI) is the transient period between posture and movement. Its central programming takes into account the environmental constraints as well as the constraints induced by the body itself. Patients with peripheral sensory neuropathies display a severe proprioceptive deficit leading to balance and gait impairments and rely on a variety of compensatory mechanisms and are known to be dependent on vision. GI was studied on eight healthy subjects and five patients in order to assess the effect of somatosensory loss on the different phases of GI, combined with a manipulation of the visual inputs. Our main hypothesis is that the proprioceptive deficit would induce an adaptation of the GI process, especially when modifying the lower part of peripheral vision. The results show that the pathology induces some adaptations of the GI process, characterized by a decrease of the motor performance (assessed by the maximal anteroposterior velocity of the center of gravity at the end of the first step), a decrease in the spatial parameters (assessed by the peak amplitude of the backward shift of the center of foot pressure during the anticipation phase and the length of the first step), and a non-modification of the temporal parameters (assessed by the duration of the anticipation phase and of the first step). The suppression of the lower part of peripheral vision has no effect on the GI process. The role of the lower part of peripheral vision seems therefore to be less critical for GI, than for balance and locomotion.

How far do patients with sensory ataxia benefit from so-called "proprioceptive rehabilitation"?

A rehabilitation program including foot sensory stimulation, balance and gait training with limited vision was performed in 24 patients with clinically defined sensory ataxia. There were 15 patients with bilateral somatosensory loss related to chronic neuropathy and nine patients with unilateral loss-related to multiple sclerosis. After training, balance control assessed using the Berg Balance Test improved similarly in both groups, and Romberg's sign disappeared in some patients, suggesting an improvement in dynamic balance and in the proprioceptive contribution. Conversely, balance assessed on a static force platform remained similar in the open-eyes condition and improved in the closed-eyes condition only in patients with unilateral sensory loss. These results show that ataxic patients can improve their balance with better results in dynamic conditions and that the relative contribution of proprioceptive and visual inputs may depend on the extent of somatosensory loss.

Posture and equilibrium in orthopedic and rheumatologic diseases.

Posture and balance may be affected in many spine or lower-limb disorders. An extensive evaluation including clinical tests and movement analysis techniques may be necessary to characterize how rheumatologic or orthopedic diseases are related to static or dynamic changes in postural control. In lower limbs, unbalance may be related to a decreased stability following arthrosis or ligament injuries at knee or ankle levels, while hip lesions appear less associated with such troubles. Spinal diseases at cervical level are frequently associated with postural changes and impaired balance control, related to the major role of sensory inputs during stance and gait. At lower levels, changes are noticed in major scoliosis and may be related to pain intensity in patients with chronic low-back pain. Whatever the initial lesion and the affected level, improvement in clinical or instrumental tests following rehabilitation or brace wearing provides argument for a close relationship between rheumatologic or orthopedic diseases and related impairments in posture and balance control.

Postural control in obese adolescents assessed by limits of stability and gait initiation.

The biomechanical changes in postural control and in motor activities linked to obesity are still not fully understood. The aim of this study was to assess the adaptation in static and dynamic control of equilibrium when the body mass to be stabilized and moved is increased through obesity. Postural stability limits and gait initiation at slow and fast velocities were compared in a case control study that included a group of obese adolescents and a control group of adolescents with normal weight. The consequences of overweight are more clearly evident from the results on dynamic stability of the obese group than those on static equilibrium. Both the lower values of the biomechanical parameters characterizing the progression velocity of gait and the longer duration of the swing phase for the fast velocity condition suggest that obesity acts as a slowing factor. However, the reduction of the postural stability limits of the obese group, their inability to increase the anticipatory phase duration unlike the control group, the increase in the double support phase duration as well as some difficulty in controlling the fall of the centre of gravity suggest that, in these subjects, an adaptive strategy is adopted to preserve equilibrium by limiting progression velocity.

Changes in balance and strength parameters induced by training on a motorised rotating platform: a study on healthy subjects.

AIM: The aim of the present study was to analyse the effects of training performed on a rotating, motorised platform (the Huber/SpineForce device from LPG Systems, Valence, France) intended to improve, postural control and muscle function. SUBJECTS: Twelve healthy adults (divided into a sedentary group and an active group) took part in a two-month training programme (involving three sessions a week) on the SpineForce whole body rehabilitation device. METHOD: Instrumental assessment of postural control (on a Satel platform) and muscle function (on a Cybex Norm) was performed before and after training. Postural control in various conditions was measured using a position parameter (the mean anteroposterior position of the centre of foot pressure [CoP]) and two stability parameters (maximum CoP displacement and CoP sway area). Assessment of the muscle function was performed during knee and spine extension and featured maximum voluntary isometric contraction (MVIC), root mean square (RMS) and neuromuscular efficiency (MVIC/RMS) measurements. RESULTS: For static postural control, we observed a more forward CoP position in the maximum backward inclination condition (p<0.01) and a decrease in maximum CoP displacement in the "eyes closed on foam" and "maximum anterior inclination" conditions. In this latter condition, a lower CoP sway area was also noted (p<0.01). In terms of muscle function, a greater MVIC for knee extension was observed in the sedentary group only (p<0.05). These changes were not correlated with each another (p<0.05). However, the value of the pretraining maximum CoP displacement predicted its final value (p<0.05). CONCLUSION: Our results suggest that static postural control responds to training on a Huber((R))/SpineForce rehabilitation device. It seems probable that a population with a low initial level of physical activity would benefit most from training on this type of device. This training could notably be applied to elderly or disabled people and especially those with sensorimotor disabilities.

[What compensatory motor strategies do patients with multiple sclerosis develop for balance control?]. / Quelles stratégies motrices de compensation les patients souffrant d'une sclérose en plaques sont-ils capables de développer pour contrôler leur équilibre?

INTRODUCTION: One of the main features of multiple sclerosis (MS) is the deterioration of motor pathway axons, and in some cases, sensory system axons. Consequently, experimental sensori-motor testing with the undisturbed upright stance paradigm might be useful. It can be hypothesized that the postural strategies could be differently affected depending on the degree of dysfunction of both sensory and motor tracts. METHODS: Twelve and fifteen patients, classified from sensory clinical tests as ataxo-spastic (SEP-AS) or only spastic (SEP-S), respectively were included in this study and compared to 12 healthy adults matched for age. The postural strategies were assessed from the centre of pressure trajectories (CP), measured from the force platform on which the subjects were instructed to stand upright eyes open for a trial lasting 51.2 s. biomechanical modelling was applied to these trajectories to compute the movements of the centre of gravity (CG) and consequently, the vertical difference between the CP and then the CP-CG, two elementary movements known to characterize postural performance movements for CGv and horizontal acceleration communicated to the CG for the CP-CG movements, and consequently overall neuro-muscular activity. To estimate the relative contribution of each of these elementary movements, an analysis based on frequency parameters (RMS and MF) was conducted. RESULTS: Both SEP-AS and SEP-S groups demonstrate larger CG and CP-CG movements than the age paired individuals. However, some statistically significant differences has to be emphasised between the two MS subgroups but only for the CP-CG component: the RMS of these movements are largely increased for the SEP-AS group, as compared to the SEP-S one. Biomechanically, this feature expresses the necessity for these very patients to produce exaggerated horizontal forces, and thus an increased energy expenditure, to handle the CG movements. The lack of effect observed for the CG movements underlines the capacity for the SEP-AS group to set appropriate control mechanisms for counteracting these less favourable initial conditions. CONCLUSION: By demonstrating specific trends in the postural organisation aimed at controlling undisturbed upright stance maintenance, this study can be of interest for the practitioner by legitimating this experimental paradigm as a simple and non invasive way to diagnose appropriately the sensori-motor deficiency.

How proprioceptive impairments affect quiet standing in patients with multiple sclerosis.

To assess if multiple sclerosis patients with proprioceptive impairment are specifically affected during quiet standing with eyes open and how they can develop motor compensatory processes, 56 patients, classified from sensory clinical tests as ataxo-spastic (MS-AS) or only having spasticity (MS-S), were compared to 23 healthy adults matched for age. The postural strategies were assessed from the centre-of-pressure trajectories (CP), measured from a force platform in the eyes open standing condition for a single trial lasting 51.2 s. The vertical projection of the centre of gravity (CGv) and its vertical difference from the CP (CP-CGv) were then estimated through a biomechanical relationship. These two movements permit the characterization of the postural performance and the horizontal acceleration communicated to the CG and from that, the global energy expenditure, respectively. Both MS-AS and MS-S groups demonstrate larger CGv and CP-CGv movements than healthy individuals of the same age. Whilst similar CGv values are noticed in both MS subgroups, suggesting similar postural performances, statistically significant differences are observed for the CP-CGv component. Biomechanically, this feature expresses the necessity for the MS-AS group to develop augmented neuro-muscular means to control their body movements, as compared to the MS-S group. By demonstrating for both groups of patients similar postural performance accompanied by a varying degree of energy expenditure to maintain undisturbed upright stance, this study reveals that MS-AS patients which are affected by proprioceptive loss can compensate for this deficit with more efficient control strategies, when standing still with their eyes open.

Continuous passive motion compared with intermittent mobilization after total knee arthroplasty. Elaboration of French clinical practice guidelines.

OBJECTIVE: To develop clinical practice guidelines concerning the use of continuous passive motion (CPM) compared with intermittent mobilization after total knee arthroplasty (TKA). METHOD: We used the SOFMER (French Physical Medicine and Rehabilitation Society) methodology, combining systematic literature review and collection of everyday clinical practice concerning postoperative rehabilitation techniques and external review by a multidisciplinary expert panel, to develop the guidelines. RESULTS: The literature contains no evidence of the advantages of CPM over other techniques of mobilization, although CPM could be adjuvant therapy used to accelerate short-term recovery. However, in France, CPM remains widely used after TKA, both in orthopedic surgery units and in physical medicine and rehabilitation services. CONCLUSION: Good methodological quality studies are needed to assess different CPM modalities and compare them to alternative intermittent mobilization techniques, particularly those with therapy starting from a flexed position.

Muscular compensation and lesion of the anterior cruciate ligament: contribution of the soleus muscle during recovery from a forward fall.

BACKGROUND: Knee stability following an anterior cruciate ligament lesion has been widely studied. Only recent studies focused on the contribution of the soleus muscle. Our purpose was to characterize the dynamic and muscular activity of balance recovery in healthy subjects and patients with an anterior cruciate ligament rupture. The role of the soleus was investigated in the ipsilateral compensation developed to stabilize the knee and in the contralateral compensation to recover balance. METHODS: Twelve anterior cruciate ligament deficient patients, ten anterior cruciate ligament repaired patients and 14 control subjects were recorded during a forward fall involving stepping to recover balance. FINDINGS: The dynamic of the centre of gravity remained normal when compared to the control group regardless of the treatment, suggesting an adapted compensation to knee instability in this situation. A bilateral increase in soleus activity was related to an increased duration in the balance recovery process in all patients. Patients used one of two strategies to recover balance regardless of the treatment: reducing the step length, involving an early recruitment of the soleus before heel contact, or anticipating braking with a similar step length requiring a predominant activity of the hamstrings. INTERPRETATIONS: These results suggest that bilateral activity of the soleus is involved to compensate for instability and highlight the contribution of the soleus to rehabilitation after an anterior cruciate ligament lesion, not only as a compensatory muscle acting at the knee level but also at a higher level in the bilateral control of stance.

Perineal neuromuscular fatigue.

AIM: The physiology of urinary continence during stress is complex and the role of passive and active mechanisms remains unclear. Coughing leads to a contraction of urethral rhabdomyosphincter and pelvic floor muscles leading to a positive urethro-vesical gradient and continence. Neuromuscular fatigue can involve all striated muscles, including rhabdomyosphincter, peri-urethral and pelvic floor muscles. This article reviews results of studies assessing perineal muscular fatigue in urinary incontinence. MATERIALS AND METHODS: A systematic review of the literature (Medline, Pascal and Embase) with use of the MESH keywords fatigue, stress, urinary incontinence, pelvic floor, urethra, urethral pressure, and muscle. RESULTS: Animal models have shown that the pelvic muscles (iliococcygeus and pubococcygeous) exhibit more neuromuscular fatigue than classical skeletal striated muscles (i.e. soleus muscle). Although the human external urethral sphincter is considered to be a highly fatigue-resistant muscle with its high proportion of slow muscle fibers, repeated coughing seems to lead to decreased urethral pressure in numerous women affected with stress urinary incontinence. In this case, "urethral fatigue" might be a possibility. CONCLUSIONS: Although few studies have focused on perineal muscular fatigue, such increased fatigue in pelvic floor muscles may play a role in the pathophysiologic features of stress urinary incontinence in women.

[Strength, postural and gait changes following rehabilitation in multiple sclerosis: a preliminary study]. / Evaluation préliminaire des effets de la rééducation sur les paramètres de force, d'équilibre et de marche dans la sclérose en plaques.

OBJECTIVE: To evaluate the impact of rehabilitation on balance, gait and strength in inpatients with multiple sclerosis (MS). METHODS: Twenty-one in patients with MS benefited from a program of rehabilitation with evaluation before and after rehabilitation. Balance was assessed by stabilometry, walking speed with use of a locometer device and maximal peak torque of knee extensor and flexor with use of an isokinetic dynamometer at 60 degrees /s speed. The functional independence measure (FIM) was also applied before and after rehabilitation. RESULTS: After rehabilitation, patients showed significant improvement in balance with opened and closed eyes, velocity gait, strength of the lower quadriceps and the higher hamstrings and FIM values. Absolute values of gait speed and strength parameters were related as were improvement in velocity speed and the higher hamstrings. CONCLUSION: The results are encouraging and confirm the interest and tolerance of a program of rehabilitation among patients with MS.

Motor determinants of gait in 100 ambulatory patients with multiple sclerosis.

A prospective analysis of gait and strength parameters was performed in 100 patients diagnosed with MS and pyramidal involvement admitted in a rehabilitation unit The patients were divided into two groups based on their ability to walk in daily life (nonassisted or cane-assisted gait) and into four clinical subgroups depending on associated involvements such as sensory loss or cerebellar ataxia. Twenty healthy subjects were studied as a control group. Gait parameters were evaluated with a Locometre and muscle strength with an isokinetic dynamometer. The results showed that the average velocity and strength of the hamstring and quadriceps were strongly correlated and reduced in the MS group in comparison with the control, and in the cane-assisted group compared with the nonassisted group. Gait velocity tended to be more correlated to hamstring strength in the nonassisted group with a determination coefficient (r2) reaching a value of 0.44 in the sensory subgroup. These findings provide evidence that a correlation between strength reduction and gait impairment is obvious whatever the clinical form in patients with MS. This correlation is higher with hamstrings but may change depending on the disability level and the clinical form. This could be taken into account in the individual assessment of further rehabilitation programmes.

[Evaluation of physiological properties of ankle braces based on a review of the literature]. / Evaluation des propriétés physiologiques des orthèses de cheville. Revue de la littérature.

INTRODUCTION: The objective of this work was to proceed to a review of the literature to assess the physiological basis of the ankle brace use. METHOD: An analysis of the international literature relating to the years 1980-2002 was carried out by questioning the Medline data bank. RESULTS: Three hundred and twenty-two articles were collected and 25 physiological studies were retained. Various changes can occur during brace use, first of all stability parameters and proprioceptive sense. Main changes affect position sense, stiffness, mobility and stability of ankle when standing. DISCUSSION: This review of the literature allows to specify the mechanisms involved by brace use in ankle stability. Some studies allow to compare the principal devices used to stabilize the ankle (taping, semi rigid braces) but, no physiological study was able to discriminate between different orthosis models. CONCLUSION: Many studies have been conducted in the field of the physiological evaluation of ankle orthosis. When these devices are widely used in current medical practice, physiological studies do not allow to characterize a better device with a specific test. These data point out the methodological difficulties in ankle brace evaluation.

[Multiple sclerosis and botulinum toxin]. / Sclérose en plaques et toxine.

INTRODUCTION: The aim of this work was to collect litterature datas to have an indication of botulinum toxin in multiple sclerosis disease. METHOD: The international literature relating the years 1982-2002 was carried out with the Medline data bank. The article presenting of the controlled studies were mainly retained. RESULTS: Thirty-seven articles were indexed, 6 were retained according to our criteria. The selected articles show mainly a use of botulinum toxin in the spasticity. The principal criteria of evaluation were the muscular tone, the spasms, the pain, the or passive amplitude of joint. Two articles report the effectiveness of toxin injection in acquired nystagmus and the paralysis of a vocal fold. DISCUSSION: This review shows that the principal indication of toxin in multiple sclerosis is spasticity with a good effectiveness of the treatment. However controlled-placebo studies among these patients are still very few. The side effects are rare but sometimes appearance of muscular weakness always making discuss the existence of a push. It is necessary to take account of these effects and their consequences before proposing the treatment. CONCLUSION: Botulinum toxin has an indication in the treatment of spasticity of patients with multiple sclerosis. However more studies are necessary with more sits of injection to fix the good indications.

[Relationship between gait speed and strength parameters in multiple sclerosis]. / Etude de la corrélation force motrice-vitesse de marche dans une population de sclérosés en plaques.

INTRODUCTION: Recent studies have focused on correlation between strength and gait parameters in hemiplegia, suggesting the interest for strength training in patients with central nervous system lesions. The aim of this study was to evaluate this correlation in multiple sclerosis (MS) patients with special regard to the different clinical forms including proprioceptive loss or cerebellar ataxia. PATIENTS AND METHOD: Gait speed and muscular function were performed in 27 patients with moderate affected gait (EDDS < 6). Gait speed was evaluated with Locometre and peak-torques of quadriceps and hamstrings were evaluated with isokinetic dynamometer. Patients were separated in three groups related to their deficiency: spastic group (8 patients), spastic with proprioceptive loss (12 patients) and spastic with cerebellar ataxia (7 patients). Gait parameters were evaluated in 10 healthy subjects as control group. RESULTS: Gait speeds (spontaneous and maximal) and peak torques of quadriceps and hamstring were similar in the three groups. In the whole patients group, gait speed was reduced and related to hamstring peak torque (r = 0.56 at spontaneous speed and 0.51 at high speed) but not with quadriceps peak torque. Patients with proprioceptive loss exhibited not only a higher correlation between gait speed and hamstring torque (r = 0.76 and 0.65 respectively) than other patients but also with quadriceps torque (r = 0.66 and 0.59 respectively) when patients in other groups did not. CONCLUSION: As it was previously pointed out in hemiplegic patients, MS patients exhibit some correlation between gait speed and muscle strength, mainly with hamstrings. These correlations can change in special sensory conditions suggesting that patients with sensory loss use different muscular strategies to maintain gait speed. Strength training may therefore be discussed in MS including specific modalities as a function of clinical parameters.

Relation between walking speed and muscle strength is affected by somatosensory loss in multiple sclerosis.

OBJECTIVE: To evaluate the correlation between gait speed and strength in multiple sclerosis (MS) with particular regard to patients presenting with proprioceptive loss. METHODS: Gait evaluation and isokinetic testing of muscular function were performed in 20 patients with unaided gait (expanded disability status scale < 6). Patients were separated into two groups in relation to the occurrence of somatosensory involvement: pyramidal group (8 patients) and sensory-pyramidal group (12 patients). Ten healthy subjects of similar age, sex, and height constituted a control group to evaluate gait parameters. RESULTS: In the whole patient group, gait speed was reduced and strongly related to hamstring peak torque but not with quadriceps peak torque. The gait speed and peak torques of quadriceps and hamstrings were similar in both groups of patients. However, in the patients with proprioceptive loss there was both a strong correlation between gait speed and hamstring torque and a significant correlation with quadriceps torque. In the pyramidal group there was poor or no correlation. CONCLUSION: In patients with undifferentiated MS there is some correlation between gait speed and muscle strength. In the case of sensory loss, a higher contribution of both flexor and extensors of the lower limbs was observed, suggesting that muscular compensation occurred in this situation to maintain gait speed. These results are relevant to assess rehabilitation modalities in MS.