Gaëtan Stoquart

Energy cost, mechanical work, and efficiency of hemiparetic walking

The energy cost of walking (C) in nine chronic hemiparetic patients was calculated by measuring the total mechanical work (Wtot) done by the muscles and the efficiency of this work production (eta). The energy cost was twice normal in slow walkers and 1.3 times greater in fast walkers. The increase in C was proportional to the increase in Wtot and eta was normal at around 20%, despite an increase in muscle tone and muscle co-contractions. This type of approach gives a greater understanding into how segmental impairments increase Wtot and C and contribute to a patients disability.

Effect of speed on kinematic, kinetic, electromyographic and energetic reference values during treadmill walking.

OBJECTIVEnEvaluation of normal and pathological gait on the level ground has drawbacks that could be overcome by walking on a treadmill. The present work was designed to assess the feasibility of extended gait analysis on a treadmill allowing multiple steps recording at a constant speed in young healthy subjects. It also aimed to provide speed-specific kinematic, kinetic, electromyographic and energetic reference values.nnnMETHODnTwelve healthy volunteers (23 +/- two years) walked on a force measuring treadmill at six speeds (1-6 k mh(-1)). Kinematics and kinetics were analysed at the hip, knee and ankle. Electromyographic muscle activity timing of quadriceps femoris, biceps femoris, tibialis anterior and lateral gastrocnemius was recorded. The energy cost was computed from oxygen consumption measurement.nnnRESULTSnAll variables were speed-dependent. Kinematics and kinetics peaks amplitude increased and occurred earlier during the walking cycle with increasing walking speed. Muscle activity timing also changed with speed, although the number of bursts remained constant. The energetic cost presented a U-shaped curve, with minimal values around 4 km h(-1). Data were compared to overground walking data obtained by several authors: all results, except kinetic ones, were similar, turning down the thought that biomechanics of treadmill and overground walking could be different.nnnCONCLUSIONnThis study provides reference values for normal and pathological walking on treadmill and allows speed-dependent comparison between subjects.

ABILOCO : a Rasch-built 13-item questionnaire to assess locomotion ability in stroke patients

OBJECTIVEnTo develop a questionnaire (ABILOCO), based on the Rasch measurement model, that can assess locomotion ability in adult stroke patients (International Classification of Functioning, Disability and Health activity domain).nnnDESIGNnProspective study and questionnaire development.nnnSETTINGnA faculty hospital.nnnPARTICIPANTSnAdult stroke patients (N=100) (age, 64+/-15y). The time since stroke ranged from 1 to 260 weeks.nnnINTERVENTIONnA preliminary questionnaire included 43 items representing a large sample of locomotion activities. This questionnaire was tested on the 100 stroke patients, and their responses were analyzed using the Rasch model (RUMM 2020 software) to select items that had an ordered rating scale and fitted a unidimensional model.nnnMAIN OUTCOME MEASUREnThe ABILOCO questionnaire.nnnRESULTSnThe retained items resulted in a 13-item questionnaire, which includes a wide range of locomotion abilities well targeted to the sample population, leading to good reliability (R=.93). The item calibration was independent of age, sex, time since stroke, and affected side. The concurrent validity of ABILOCO was also investigated by comparing it with well-known, criterion standard scales (Functional Walking Category, Functional Ambulation Categories, item 12 of the FIM instrument evaluating walking ability) and the walking speed measured with the 10-meter walk test.nnnCONCLUSIONSnThe ABILOCO questionnaire presents good psychometric qualities to measure locomotion ability in adult stroke patients. Its range and measurement precision make it attractive for clinical use throughout the rehabilitation process and for clinical research.

EFFECTS OF SElECTIvE TIBIAl NERvE NEUROTOMy AS A TREATMENT FOR ADUlTS PRESENTINg WITH SPASTIC EqUINOvARUS FOOT: A SySTEMATIC REvIEW

OBJECTIVEnSpastic equinovarus foot is a major cause of disability for neurorehabilitation patients, impairing their daily activities, social participation and general quality of life. Selective tibial nerve neurotomy is a neurosurgical treatment for focal spasticity, whose acceptance as treatment for spastic equinovarus foot remains controversial. We performed a systematic review of the literature to assess the efficacy of tibial nerve neurotomy as a treatment for adult patients presenting with spastic equinovarus foot.nnnMETHODSnWe queried PubMed, Science Direct, Trip Database and PEDro databases with the following keywords: equinus deformity OR muscle spasticity AND neurotomy.nnnRESULTSnWe selected a total of 11 non-randomized and uncontrolled studies, suggesting that neurotomy could be an efficient treatment to reduce impairments in spastic equinovarus foot patients.nnnDISCUSSIONnOur conclusions are based primarily on case series studies. The effects of tibial nerve neurotomy had not been compared with a reference treatment through a randomized controlled trial, which would be necessary to increase the level of scientific evidence. Moreover, further studies using quantitative, validated and objective assessment tools are required to evaluate the efficacy of tibial nerve neurotomy accurately based on the International Classification of Functioning, Disability and Health from the World Health Organization.

The effect of botulinum toxin injections on gait control in spastic stroke patients presenting with a stiff-knee gait.

INTRODUCTIONnBotulinum toxin type A (BoNT-A) injections are known to improve walking impairments and activity in spastic hemiparetic stroke patients presenting with a stiff-knee gait [Caty GD, Detrembleur C, Bleyenheuft C, Deltombe T, Lejeune TM. Effect of simultaneous botulinum toxin injections into several muscles on impairment, activity, participation, and quality of life among stroke patients presenting with a stiff knee gait. Stroke 2008;39(October (10)):2803-8]. The aim of the present study was to understand how the improvement of mechanical variables during gait is controlled by the central nervous system after BoNT-A injections. Therefore, we used Kinematic Segmental Coordination (KSC), i.e. the kinematic covariation law of elevation angles between lower limb segments, to assess their effect on gait control. As far as we know, this has never been studied before.nnnMETHODSnTwenty chronic hemiparetic stroke patients presenting with a stiff-knee gait performed an instrumented gait analysis at the same walking speed before and 2 months after BoNT-A injection in several spastic muscles. We used the kinematic recordings previously obtained by Caty et al. [Caty GD, Detrembleur C, Bleyenheuft C, Deltombe T, Lejeune TM. Effect of simultaneous botulinum toxin injections into several muscles on impairment, activity, participation, and quality of life among stroke patients presenting with a stiff knee gait. Stroke 2008;39(October (10)):2803-8] and computed KSC following Borgheses methodology. The treatment effect was tested using a repeated measures ANOVA.nnnRESULTSnBoNT-A injections allowed a statistically significant improvement in KSC of both lower limbs (p=0.004). Moreover, the unaffected side KSC reached normal values after BoNT-A injections.nnnCONCLUSION AND DISCUSSIONnBoNT-A allowed an improvement in KSC of the affected lower limb and a normalization of KSC of the unaffected limb. This improvement could either be due to a mechanical effect or a central effect of BoNT-A via the spinal central pattern generators (CPGs).

A Randomized Controlled Trial of Selective Neurotomy Versus Botulinum Toxin for Spastic Equinovarus Foot After Stroke

Background. Selective neurotomy is a permanent treatment of focal spasticity, and its effectiveness in treating spastic equinovarus of the foot (SEF) was previously suggested by a few nonrandomized and uncontrolled case-series studies. Objectives. This study is the first assessor-blinded, randomized, controlled trial evaluating the effects of this treatment. Methods. Sixteen chronic stroke patients presenting with SEF were randomized into 2 groups: 8 patients underwent a tibial neurotomy and the remaining 8 received botulinum toxin (BTX) injections. The soleus was treated in all patients, and the tibialis posterior and flexor hallucis longus were treated in about half of patients. The primary outcome was the quantitative measurement of ankle stiffness (L-path), an objective measurement directly related to spasticity. Participants were assessed by a blind assessor before their intervention and at 2 and 6 months after treatment. Evaluations were based on the 3 domains of the International Classification of Functioning, Disability and Health (ICF). Results. Compared with BTX, tibial neurotomy induced a higher reduction in ankle stiffness. Both treatments induced a comparable improvement of ankle kinematics during gait, whereas neither induced muscle weakening. Activity, participation, and quality of life were not significantly modified in either group. Conclusions. This study demonstrates that the tibial nerve neurotomy is an effective treatment of SEF, reducing the impairments observed in chronic stroke patients. Future studies should be conducted to confirm the long-term efficacy based on the ICF domains.

Feasibility of a self-rehabilitation program for the upper limb for stroke patients in Benin.

INTRODUCTIONnStroke is a major cause of disability and represents a very high cost in developing countries. Self-rehabilitation programs represent a new and original treatment for stroke patients, likely to reduce upper limb impairments and improve activity and participation. The goal of this study is to evaluate the feasibility of a self-rehabilitation protocol in Benin.nnnMETHODSnTwelve chronic stroke patients carried out the upper limb self-rehabilitation program (3 hours/day, 5 days/week for 2 weeks). The performance of these patients was evaluated before and after the self-rehabilitation program, by measuring the number of exercises that patients were able to achieve during a three-hour session, and by assessing their gross manual dexterity.nnnRESULTSnTwelve patients were effectively able to complete the entire program. The number of unimanual exercises and self-mobilizations performed during a three-hour session as well as the score of the Box and Block test were improved by the self-rehabilitation program (P<0.05).nnnDISCUSSION AND CONCLUSIONnSelf-rehabilitation programs are feasible and inexpensive as they do not involve a therapist. It is then a promising approach in stroke rehabilitation, particularly in developing countries, where rehabilitation costs are usually supported by patients.

Comment: How and why to predict spasticity after stroke?

Although many stroke patients present with spasticity, this impairment remains a riddle for physicians. Why, when, and how does a patient develop spasticity, whereas another patient with a similar cerebral lesion does not? Moreover, the evolution of spasticity among these chronic patients and its relation to functional activity are not straightforward. Thus, the assessment and treatment of spasticity remain a challenge in neurorehabilitation.