Arnaud Dupeyron

Pressure ulcer risk factors in persons with spinal cord injury Part 2: the chronic stage

Introduction:Pressure ulcers (PUs) are a common complication following spinal cord injury (SCI). Prevalence for persons in the chronic SCI stage varies between 15 and 30%. The risk assessment scales used nowadays were designed on pathophysiological concepts and are not SCI-specific. Recently, an epidemiological approach to PU risk factors has been proposed for designing an SCI-specific assessment tool. The first results seem quite disappointing, probably because of the level of evidence of the risk factors used.Objective:To determine PU risk factors correlated to the chronic stage of SCI.Materials and methods:Systematic review of the literature.Results:There are several PU risk factors for chronic SCI stage: socio-demographics, neurological, medical or behavioral. The level of evidence varies: it is quite high for the socio-demographics and neurological factors and low for behavioral factors.Discussion and conclusion:Behavioral risk factors (relieving the pressure, careful skin monitoring, smoking) are probably the ones for which a preventive strategy can be established. It is important to develop specific assessment tools for these behavioral risk factors to determine their relevance and evaluate the effect of therapeutic educational programs on persons with SCI.

Pressure ulcer risk factors in persons with SCI: Part I: Acute and rehabilitation stages.

Background:Pressure ulcers (PUs) are a common complication following a spinal-cord injury (SCI). Good prevention requires identifying the individuals at risk for developing PUs. Risk assessment scales used nowadays were designed on pathophysiological concepts and are not SCI-specific. Recently, an epidemiological approach to PU risk factors has been proposed to design an SCI-specific assessment tool. The first results seem quite disappointing, probably becuase of the level of evidence of the risk factors used.Objective:To determine PU risk factors correlated to the patients with SCI, medical care management during the acute as well as in the rehabilitation and chronic stages. This first part focuses on identifying the risk factors during the acute and rehabilitation stages.Materials and methods:Systematic review of the literature.Results:Six studies met our inclusion criteria. The risk factors during the acute stage of an SCI are essentially linked to care management and treatment modalities. There is insufficient evidence to make a recommendation on medical risk factors, except for low blood pressure on admission to the Emergency Room, with a moderate level of evidence. Regarding the rehabilitation stage, no study was deemed relevant.Discussion and conclusions:Additional observational studies are needed, for both the acute and rehabilitation stages, to improve this level of evidence. However, this systematic review unveiled the need for a carefully assessed t care management and the related practices, especially during the acute stage of an SCI.

Influence of back muscle fatigue on lumbar reflex adaptation during sudden external force perturbations.

There is still conflicting evidence about the influence of fatigue on trunk reflex activity. The aim of this study was to measure response latency and amplitude changes of lumbar and abdominal muscles after heavy external force perturbation applied to the trunk in the sagittal plane before and after back muscle fatigue, in expected and unexpected conditions. Ten healthy subjects in a semi-seated position, torso upright in a specific apparatus performed an intermittent back muscle fatigue protocol. EMG reflex activity of erector spinae (ES) and external oblique muscles were recorded in unexpected and in expected (self pre-activation) conditions. After fatigue, the normalized reflex amplitude of ES increased in expected and unexpected conditions (P<0.05) while ES response latency was slightly decreased. Reflexes latencies for ES were systematically shorter (P<0.05) of 25% in expected compared to unexpected conditions. These findings suggest that a large external force perturbation would elicit higher paraspinal magnitude responses and possible earlier activation in order to compensate the loss of muscular force after fatigue. Because of the seated position the postural adjustments were probably not triggered and thus explain the lack of abdominal activation. The self-anticipated pre-activation in order to counteract perturbations was not affected by fatigue illustrating the natural muscular activation to maintain trunk stability.

Evaluation of the benefits of low back pain patients’ education workshops during spa therapy

OBJECTIVES To evaluate the medium-term impact of education workshops on low back pain (LBP) in the setting of a thermal spa on: fear-avoidance beliefs, disability, pain, and satisfaction. METHODS Randomized prospective alternate-month design-type study including 360 individuals having thermal spa therapy for LBP: 188 in the intervention group (three standardized education workshops lasting 1 h 30 each and usual thermal therapy for 3 weeks), 172 in the control group (usual thermal therapy and non-standardized verbal information). The principal analysis criterion was the difference in the fear-avoidance beliefs (physical FABQ) score between baseline and 6 months after the therapy; secondary criteria were: evolution of disability (Quebec Scale) and pain intensity (Visual Analogue Scale), and satisfaction with the information received. RESULTS There was a significant reduction in the physical FABQ score at 6 months (P<0.05), and this reduction was more marked in the intervention group (-5.8±0.7 vs. -2±0.72 points out of 24; P<0.0001). Disability and pain significantly decreased in both groups (P<0.05), with no difference between groups. These workshops also had a significant effect on satisfaction with the information received. CONCLUSION Standardized education workshops have a beneficial impact on LBP and contribute to an improvement in the medical services provided during spa therapy by reducing the effect of fear-avoidance beliefs as well as relieving pain. Extending the use of such workshops could contribute to enhance the positive impact of spa therapy in the management of chronic disabling diseases.

Reproducibility of isokinetic peak torque assessments of the hip flexor and extensor muscles.

OBJECTIVES Isokinetic assessment is currently the reference method for measuring dynamic muscle strength. We have sought to evaluate the reproducibility over time of isokinetic testing of the hip flexor (FI) and extensor (Ext) muscles and to establish whether there is a significant difference in peak torque (PT) between the left and right hips. PATIENTS AND METHODS Ten adults were tested once a week for 3 weeks by the same investigator and according to the same protocol, with two velocities (60 degrees /s and 180 degrees /s) for the hip FI and Ext in concentric tests and one velocity (30 degrees /s) for the Ext only in eccentric tests. The reproducibility of the measured PT was analyzed by using the intraclass correlation coefficient (ICC) and a Bland and Altman plot. The difference in PT between the right and left hips was tested using Students T test. RESULTS The ICC for the observed PT values revealed very good reproducibility (with a value of between 0.75 and 0.96) for the hip FI and Ext measurements (regardless of the body side, test velocity or contraction mode). We did not observe any significant PT differences between the right and left hips. CONCLUSION The isokinetic assessment of the concentric and eccentric PT values generated by the hip FI and Ext is highly reproducible. There is no difference between dominant and nondominant body sides, which enables the use of the contralateral limb as a reference.

Which physical activities and sports can be recommended to chronic low back pain patients after rehabilitation

BACKGROUND Physical exercise is widely prescribed in rehabilitation programmes for low back pain (LBP). The LBP patient often asks whether this physical activity should be maintained and, in some cases, whether he/she should resume or take up a sport. PURPOSE To answer these two questions by performing a review of literature on the efficacy and safety of post-rehabilitation physical activities and sport in LBP. METHOD A systematic search of computerized databases from 1990 to 2011 was performed using grade 1 to 4 studies articles in English or French. RESULTS Of the 2583 initially identified articles, 121 articles were analysed. Globally, physical activities like swimming, walking and cycling, practiced at moderate-intensity help to maintain fitness and control pain. Inconsistent results were found for avoiding recommendations according to the nature of PA. Sport activities, except ballgames, can be easily resume or take up as tennis, horse riding, martial arts, gymnastics, golf and running which can be performed at a lower intensity or lower competitive level. DISCUSSION AND CONCLUSION Moderate but regular physical activity helps to improve fitness and does not increase the risk of acute pain in chronic LBP patients. The resumption of a sport may require a number of adaptations; dialogue between the therapist and the sports trainer is therefore recommended.

Precision of estimates of local stability of repetitive trunk movements

PurposeLocal dynamic stability of trunk movements quantified by means of the maximum Lyapunov exponent (λmax) can provide information on trunk motor control and might offer a measure of trunk control in low-back pain patients. It is unknown how many repetitions are necessary to obtain sufficiently precise estimates of λmax and whether fatigue effects on λmax can be avoided while increasing the number of repetitions.MethodTen healthy subjects performed 100 repetitions of trunk movements in flexion, of trunk rotation and of a task combining these movement directions. λmax was calculated from thorax, pelvis and trunk (thorax relative to pelvis) kinematics. Data series were analyzed using a bootstrap procedure; ICC and coefficient of variation were used to quantify precision as a function of the number of cycles analyzed. ANOVA was used to compare movement tasks and to test for effects of time.ResultsTrunk local stability reached acceptable precision level after 30 repetitions. λmax was higher (indicating lower stability) in flexion, compared to rotation and combined tasks. There was no time effect (fatigue). λmax of trunk movement was lower and less variable than that of thorax and pelvis movements.ConclusionsThe data provided allow for an informed choice of the number of repetitions in assessing local dynamic stability of trunk movements, weighting the gain in precision against the increase in measurement effort. Within the 100 repetitions tested, fatigue did not affect results. We suggest that increased stability during asymmetric movement may be explained by higher co-activation of trunk muscles.

Muscle oxygenation and intramuscular pressure related to posture and load in back muscles

BACKGROUND CONTEXT There is little information about the simultaneous changes of intramuscular pressure (IMP) and oxygen saturation (StO(2)) of the paraspinal muscle under various conditions of posture and load. PURPOSE To measure simultaneously and compare IMP and StO(2) across a range of static trunk postures commonly observed during normal work tasks. STUDY DESIGN A prospective study using a repeated-measure design in clinical setting. PATIENT SAMPLE Sixteen healthy young men with no history of back pain. OUTCOME MEASURES Simultaneous measurements of IMP by a flexible slit catheter and StO(2) by near infrared spectroscopy of the multifidus muscle were performed. METHODS The two measures were taken in six static posture tasks: standing upright and bending forward with and without load (20kg), bending backward and during a sustained isometric contraction (ie, Sorensen test). To compare the influence of the tasks on IMP and StO(2) variables, a one-way variance analysis with repeated measures was used. Spearmans rank correlation coefficient (rho) was determined between the two variables for each posture task. RESULTS We observed only a moderate but significant correlation between IMP and StO(2) values in upright standing and a trend in bending forward positions with load (p<.05). IMP increased in the bending backward position and showed the greatest increase during the Sorensen test. StO(2) decreased significantly during the Sorensen test, in the bending forward position with and without load bearing but did not in bending backward. CONCLUSION The simultaneous recording of IMP and StO(2) of the multifidus muscle allows a deeper insight of physiological events during various trunk postures. In the mutifidus muscle, there is no evident linear relationship between IMP and StO(2) values in various static postures of the trunk in young males. This preliminary study shows that IMP may play a role on StO(2) only in some circumstances, such as a prolonged endurance test or in a bending forward position with a significant load bearing.

Painful camptocormia: the relevance of shaking your patient’s hand

Camptocormia is an abnormal posture with marked flexion of thoracolumbar spine that abates in the recumbent position. Camptocormia has been described in various neurological (Parkinsonism), muscular (myopathy), psychogenic or orthopedic disorders. There are several hypotheses that can explain this impaired posture but they are usually related to the concomitant pathologies. We report the first case of a patient with confirmed myotonic dystrophy addressed to our medical center for impaired posture who underwent extensive medical exams and explorations because of a myotonic hand. Axial weakness and muscle atrophy, validated by CT-scan imaging, are discussed independent of the concomitant pathology (Parkinson, myopathy).

Does an abdominal strengthening program influence leg stiffness during hopping tasks

Abstract Dupeyron, A, Hertzog, M, Micallef, JP, and Perrey, S. Does an abdominal strengthening program influence leg stiffness during hopping tasks? J Strength Cond Res 27(8): 2129–2133, 2013—According to the spring mass model, leg stiffness (characterized by the measure of kleg) behavior is theoretically dependent on lower limb joint and trunk stiffness. Yet, the influence of the trunk as a possible regulator of kleg is unknown. This study investigated the influence of abdominal training on kleg during hopping tasks. Fourteen young male (age 18.5 ± 0.5 years, height 176.4 ± 4.3 cm, weight 69.9 ± 5.5 kg) soccer players (national level) participated in the study. Two groups (bracing B group, n = 7 vs. hollowing transversus abdominis [TrA] H group, n = 7) with identical training load followed an 8-week training program for abdominal strengthening. Contact time, flight time, jump height, and kleg were measured with an OptoJump system during a standardized hopping task (2.2 Hz) before and after the training program. Results for each group showed that only the H group increased kleg after the intervention (+15.7%) compared with the B group (+5.9%). This difference was explained by a 6.5% decrease in contact time in H group (−2.4% in B) with increased flight time (+8.8% in H vs. +2% in B). A large increase was found for jump height in H (+16.9%) compared with B group (+4.4%). This study showed that TrA strengthening improves leg stiffness in hopping tasks. Our findings suggest the potential role of abdominal muscles in controlling “lumbopelvic” stiffness as a part of the spring according to the spring mass model, and thus influencing kleg by reduced ground contact phase.