[Innovations in physical and rehabilitation medicine]. / Innovations en médecine physique et réadaptation.

Over the last decade, Physical and Rehabilitation Medicine (PRM) is a medical specialty that has evolved considerably in the various fields that concern it : from the management of low back pain and lumbosciatalgia or osteoporosis in a multidisciplinary manner, through the use of new technologies in neuro-locomotor rehabilitation and robotisation in amputee patients for example, the development of regenerative medicine and prevention in sports traumatology and, finally, the progress of electrophysiology techniques for the diagnosis of small-fibre neuropathies. These various advances will be discussed in this article.

Au cours de la dernière décennie, la Médecine Physique et Réadaptation (MPR) est une spécialité médicale qui a fortement évolué dans les différents domaines qui la concernent : de la prise en charge des lombalgies et lombosciatalgies ou encore de l'ostéoporose de manière pluridisciplinaire, en passant par l'utilisation des nouvelles technologies en rééducation neuro-locomotrice et de la robotisation en rééducation, chez les patients amputés par exemple, le développement de la médecine à vocation régénérative et la prévention en traumatologie du sport et, enfin, les progrès des techniques d'électrophysiologie pour le diagnostic des neuropathies à petites fibres. Ces différentes avancées seront abordées dans cet article.

Deficits of ankle muscle strength not found in children, adolescents and young adults with haemophilic ankle arthropathy.

OBJECTIVES: Adequate management of haemophilia patients requires early detection of joint impairment in relatively asymptomatic patients. This study sought to quantify the impact of the ankle's structural impairment on muscle strength in children, adolescent and young adults with haemophilia (CAAwH). METHODS: Twenty-three CAAwH underwent bilateral magnetic resonance imaging (MRI) assessing the anatomical status of tibiotalar joint (TTJ) and subtalar joint (STJ) using the International Prophylaxis Study Group MRI scale. An isokinetic dynamometer enabled a detailed evaluation of muscle strength at slow and fast speed. In parallel, 10 typically developing healthy boys (TDB) participated in a 1-week interval test-retest assessment to assess the test's reliability. RESULTS: Forty-six MRI ankle scores were obtained, with 11 patients unilaterally affected and one bilaterally. Of the 13 affected feet, nine showed abnormalities at TTJ, three at the posterior STJ and the remaining one at both joints. Muscle strength was not reduced in CAAwH exhibiting TTJ and/or STJ arthropathy, as compared to healthy TDB, nor was there any difference between the CAAwH's affected or unaffected sides. CONCLUSION: Contrarily to adult patients, CAAwH with repeated ankle bleeding may be less impaired than current structural evaluations imply, with possibly a latency between the occurrence of structural and functional damage.

Prevalence of sarcopenia in a population of nursing home residents according to their frailty status: results of the SENIOR cohort.

OBJECTIVE: To investigate the relationship between frailty and sarcopenia, by evaluating the prevalence of sarcopenia among frail, pre-frail and robust elderly nursing home residents in Belgium. METHODS: This is an analysis of baseline data collected from the SENIOR (Sample of Elderly Nursing home Individuals: an Observational Research) cohort. All subjects received a sarcopenia evaluation, based on the definition proposed by the European Working Group on Sarcopenia in Older People (EWGSOP). The frailty evaluation was primarily based on FRIED's definition but also on 9 other operational definitions. RESULTS: A total of 662 subjects (73.1% of women) were included in this analysis (mean age: 83.2±8.99 years). The prevalence of sarcopenia was 38.1% whereas the prevalence of frail and pre-frail persons was respectively 24.7% and 61.4%. Among frail, pre-frail and robust subjects, respectively 47%, 38.9% and 16.3% were diagnosed sarcopenic. The prevalence of sarcopenia according to ten different operational definitions of frailty ranged between 32.8 % (i.e. Frail scale Status and Frailty Index) and 47% (i.e. Fried definition). CONCLUSION: This research highlights that over a third of nursing home residents are sarcopenic and the percentage is almost 50% among frail subjects; those latter constitute about 1 in 4 of the population of nursing home residents studied here.

Data set of healthy old people assessed for three walking conditions using accelerometric and opto-electronic methods.

BACKGROUND: Gait patterns of healthy aging are needed to allow a comparison with pathological situations. However, little data is available. OBJECTIVE: To present gait pattern of healthy older specially selected to be "healthy walkers". METHOD: Fifty-seven older people benefited from a geriatric assessment including clinical and functional evaluations to include only those without gait disorders. Gait data were simultaneously recorded using a tri-axial accelerometer placed on the waist and four 3D position markers placed on the feet at the level of the heel and the toe. Volunteers walked at comfortable self-selected speed (CW), fast self-selected speed (FW), and finally in dual task walking condition (DTW). The extracted gait parameters were: gait speed, stride length, stride frequency, regularity and symmetry, swing, stance and double support time and ratio and minimum toe clearance. Gait speed and stride length were normalized to the right leg length. RESULTS: Fifty-seven older people with a mean age of 69.7 ± 4.2 years old (range from 65 to 82 years) were included. Data were analyzed according to the gender and according to the age (<70 or ≥70 years old). After normalization to leg length, the main significant differences were shown for stride length and minimum toe clearance in CW, FW and in DTW that were shorter in women. The regularity in FW was significantly lower among older volunteers. CONCLUSIONS: This work provides a data set considering 14 gait parameters obtained from 57 healthy old people strictly selected and assessed for three walking conditions and shows that GS, SL and MTC have to be related to the gender. The age-related impact on gait performances appears reduced in this cohort.

Relationship between frailty, physical performance and quality of life among nursing home residents: the SENIOR cohort.

BACKGROUND: The aim of this study was to assess the relationship between frailty and a large number of indicators related to physical and muscular performance as well as quality of life. METHODS: This is an analysis of data collected at baseline in the Sample of Elderly Nursing home Individuals: an Observational Research (SENIOR) cohort including nursing home residents. Subjects are volunteer, oriented and able to walk (walking assistance allowed) nursing home residents in Belgium. A large number of demographic and clinical characteristics, including physical and muscular performance, were collected from each patient. The prevalence of frailty in this population was assessed using Fried's definition. RESULTS: In total, 662 subjects are included in this analysis. The mean age of the sample is 83.2 ± 8.99 years, and 484 (73.1 %) are women. In this population of nursing home residents, the prevalence of frailty is 25.1 %, pre-frailty, 59.8 % and robustness, 15.1 %. Compared to non-frail subjects, frail subjects have lower physical and muscular performances and a lower quality of life. CONCLUSION: Frailty, according to Fried's definition, seems to be associated with several clinical indicators suggesting a higher level of disability and an increased propensity to develop major clinical consequences. Follow-up data of the SENIOR cohort will be helpful in confirming these findings, establishing cause-effect relationships and identifying the most predictive components of physical frailty for adverse outcomes in nursing homes.

Gait speed or gait variability, which one to use as a marker of risk to develop Alzheimer disease? A pilot study.

BACKGROUND: Previous literature demonstrates the interest of gait analysis to predict cognitive decline in old people. AIMS: This pilot study aims to determine if gait speed or gait variability is a marker able to early identify, among mild cognitive impairment (MCI) subjects, those at risk to develop Alzheimer's disease (AD) in the future. METHODS: 13 MCI subjects were included in 2007. Their gait parameters (walking speed, stride length and gait frequency, regularity and symmetry) were measured in 2007 and 2008 in simple task (ST) and in dual task (DT) using a triaxial accelerometer (Locometrix(®)). Among the 13 MCI subjects included in 2007, 10 were assessed in 2008. So, 23 (13 in 2007 + 10 in 2008) gait tests were collected. In 2011, MCI people were considered as "MCI+" when they developed AD (between baseline and 2011) and as "MCI-" if they did not. Among the 23 gait tests, 15 were from MCI+ (9 gait tests in 2007 and 6 in 2008) and 8 from MCI- (4 gait tests in 2007 and 4 gait tests in 2008). Mann-Whitney non-parametric U test was used to compare gait parameters of MCI+ and MCI-. RESULTS: Gait speed, symmetry and regularity were lower in MCI+ than in MCI-. DISCUSSION: Despite the small sample size, the results presented in this original pilot study are in line as the infrequent previous literature related to this topic. The authors discuss lacks and strengths of this work. CONCLUSIONS: These results suggest that both gait speed and gait variability could be markers to early identify MCI at risk to develop AD.

Physiological Interpretation of the Slope during an Isokinetic Fatigue Test.

To assess the relationship between selected measures (the slope and average performance) obtained during a high intensity isokinetic fatigue test of the knee (FAT) and relevant measures of anaerobic and aerobic capacities. 20 well-trained cyclists performed 3 randomly ordered sessions involving a FAT consisting in 30 reciprocal maximal concentric contractions of knee flexors and extensors at 180°.s(-1), a maximal continuous graded exercise test (GXT), and a Wingate anaerobic test (WAnT). The slope calculated from peak torque (PT) and total work (TW) of knee extensors was highly associated to maximal PT (r=-0.86) and maximal TW (r=-0.87) measured during FAT, and moderately associated to peak power output measured during the WAnT (r=-0.64 to -0.71). Average PT and average TW were highly associated to maximal PT (r=0.93) and maximal TW (r=0.96), to mean power output measured during WAnT (r=0.83-0.90) and moderately associated to maximal oxygen uptake (0.58-0.67). In conclusion, the slope is mainly determined by maximal anaerobic power, while average performance is a composite measure depending on both aerobic and anaerobic energy systems according to proportions that are determined by the duration of the test.

[New conservative treatments of chronic tendinopathies]. / NOUVEAUX TRAITEMENTS CONSERVATEURS DES TENDINOPATHIES CHRONIQUES.

The pathophysiological mechanisms of tendinopathies integrate various intrinsic and extrinsic factors. Classic "passive" therapeutics have a limited action. Because of a better pathophysiological understanding of tendinopathies, more recent treatments (injections of various compounds, infiltrations of platelet-rich plasma, stem cells) would lead to a long-term healing. In case of failure of conservative managements and depending on the anatomical site, a surgical approach may be considered.

[Critical analysis of classical conservative treatments of tendinopathies]. / Analyse critique des traitements conservateurs classiques des tendinopathies.

Classic "passive" therapeutics (anti-inflammatory drugs, infiltrations of corticosteroids...) of tendinopathies, which are used relatively empirically, reduce pain and inflammation, without fundamentally changing the tendon structure. The eccentric rehabilitation has been applied to chronic tendinopathies, not only due to the failure of conventional therapies but also due to a better pathophysiological understanding of tendinopathies. Various studies underscore the effectiveness of eccentric rehabilitation which, after 20-30 sessions, leads to healing and especially prevents the risk of chronicity. Shockwave therapy, amending the tendinous structure, would lead to a long term healing.

[Chronic tendinopathies and platelet-rich plasma]. / Plasma riche en plaquettes et lésions tendineuses.

Platelets contain growth factors released during their degranulation following activation. These growth factors promote tissue remodeling, wound healing and angiogenesis. Currently, the clinical effect of Platelet-Rich Plasma (PRP) is still discussed, or even controversial. Our researches have assessed the effectiveness of PRP on the healing of animal tendons and human beings suffering from chronic jumper's knee.

Posterior thigh muscles activity during the active H-test: An electromyographic and kinematic analysis.

The Askling's H-test is considered a useful return to play criterion after a hamstring muscle injury (HMI). However, it assesses only the active and passive flexibility of posterior thigh muscles. This may lead the practitioner to underestimate a compensation or abnormal movement pattern. The aim of this study was to analyze these kinematic aspects and their reliability, and evaluate the hamstring (HM) and gluteus maximus (GM) muscles' activities. Twelve healthy male volunteers were tested during two session of three trials for passive and active tests. Dynamic flexibility (97.2 ± 6.0°) was significantly greater than the passive one (70.5 ± 14.7°) (p < 0.001), and good intra-individual reproductibility for most kinematic characteristics was observed. Biceps Femoris long head, semitendinosus and GM mean activities (20.1 ± 11.2%; 14.3 ± 7.3% and 25.2 ± 22.1%, respectively) were found to be low to moderate, indicating that only a moderate level of activity occurred during the active H-test, in comparison to other movements such as sprinting itself. In addition, the activity of the posterior thigh muscles during the active H-test appeared to be variable among the volunteers. These findings suggest that the H-test should be interpreted on an individual basis rather than relying on general characteristics, and be considered as an intermediate tool before more strenuous activities such as returning to sprint. With this comprehensive approach, clinicians can gain a more accurate understanding of their patients' progress and make more informed decisions about their readiness to return to play.

Muscle fatigue experienced during maximal eccentric exercise is predictive of the plasma creatine kinase (CK) response.

Unaccustomed eccentric exercise may cause skeletal muscle damage with an increase in plasma creatine kinase (CK) activity. Although the wide variability among individuals in CK response to standardized lengthening contractions has been well described, the reasons underlying this phenomenon have not yet been understood. Therefore, this study investigated a possible correlation of the changes in muscle damage indirect markers after an eccentric exercise with the decline in muscle performance during the exercise. Twenty-seven healthy untrained male subjects performed three sets of 30 maximal isokinetic eccentric contractions of the knee extensors. The muscular work was recorded using an isokinetic dynamometer to assess muscle fatigue by means of various fatigue indices. Plasma CK activity, muscle soreness, and stiffness were measured before (pre) and one day after (post) exercise. The eccentric exercise bout induced significant changes of the three muscle damage indirect markers. Large inter-subject variability was observed for all criteria measured. More interestingly, the log (CK(post) /CK(pre)) and muscle stiffness appeared to be closely correlated with the relative work decrease (r = 0.84, r(2) = 0.70 and r = 0.75, r(2) = 0.56, respectively). This is the first study to propose that the muscle fatigue profile during maximal eccentric protocol could predict the magnitude of the symptoms associated with muscle damage in humans.

Isokinetic intervention in microtraumatic shoulder instability: an update.

AIM: Aim of the present study was to carry out a critical analysis of the use of isokinetic dynamometers for evaluation and rehabilitation in microtraumatic shoulder instability. METHODS: A non-systematic literature review was conducted on Medline using the following key words: "isokinetics", "shoulder instability", "evaluation", "rehabilitation". We also analyzed the related articles, and compiled a database of expert opinion. RESULTS: Despite a lack of consensus on testing modalities, lateral and medial rotator muscle strength can be safely and reliably assessed on isokinetic devices in subjects presenting with microtraumatic instability of the shoulder, before and after rehabilitation and/or surgery. There is considerable inter-individual variability in the results, leading to consider isokinetic testing as a useful examination before individualized rehabilitation. Its use as a muscle strengthening method in a global rehabilitation program seems interesting in order to correct rotator muscle strength deficiencies and/or asymmetries, which may be infra-clinical, even though strong scientific evidence is still lacking. CONCLUSION: Isokinetics is a safe tool for evaluation and seems to be effective in rehabilitation for microtraumatic instability of the shoulder. It would, however, be necessary to standardize practices thanks to rigorous clinical studies, so as to determine precisely the indications of this technique in the comprehensive management of shoulder instability.

Association between preseason functional tests and injuries in youth football: a prospective follow-up.

This prospective cohort study aimed at identifying player-related risk factors for injuries in youth football as determined by extensive preseasonal screening. All male U15-U19 players from a regional football school (season 2007-2008; n = 67) underwent preseason evaluations assessing physical fatigue, emotional stress and injury history (questionnaire), anthropometric variables, general joint laxity (Beighton score), lower limb coordination (functional hop tests), aerobic fitness (shuttle run test), strength of knee extensor and flexor muscles (isokinetic tests), static and dynamic balance (force plate tests), and explosive strength (jump tests on force plate). Football exposure and all football-related injuries (n = 163) were recorded during the entire subsequent season (44 weeks). Total injury incidence was 10.4 injuries/1000 h and was higher in competition than in training [relative risk = 3.3; CI(95%) (2.39; 4.54); P < 0.001]. Lower limb injuries were most frequent (87%). Acute contact injuries represented 37%, while intrinsic (noncontact and chronic) injuries amounted to 63%. Of all the variables tested, only physical fatigue was significantly associated with injury, as revealed by univariate and multivariate analyses. The same result was observed when considering only intrinsic injuries as outcome. A single preseason test session may be of limited interest in the framework of an injury prevention strategy.

Effect of the lengthening of the protocol on the reliability of muscle fatigue indicators.

The aim of this study was to examine absolute and relative reliability of fatigue measures calculated from peak torque or total work during 20, 30, 40 and 50 reciprocal maximal concentric contractions performed on an isokinetic dynamometer at 180 degrees x s(-1). Eighteen moderately active men performed 50 reciprocal maximal concentric contractions on three occasions with one 7-10 days recovery between each session. Peak torque and total work were computed for each contraction and subsequently summed to compute cumulated performance after respectively 20, 30, 40 and 50 repetitions. Muscle fatigue was determined after 20, 30, 40 and 50 repetitions by the fatigue index, the percent decrease in performance and the slope. Reliability of average peak torque or average total work was similar and was not affected by the lengthening of the protocol, although a learning effect was evident for knee flexors. Reliability of fatigue measures calculated from peak torque or total work was similar, improved with the lengthening of the protocol and was better for knee extensors. Measuring average peak torque or average total work and the slope during a protocol involving 30 maximal reciprocal concentric contractions appear to represent a better compromise between reliability and physiological interpretability of the data.

Muscular strength, functional performances and injury risk in professional and junior elite soccer players.

Muscle strength and anaerobic power of the lower extremities are neuromuscular variables that influence performance in many sports activities, including soccer. Despite frequent contradictions in the literature, it may be assumed that muscle strength and balance play a key role in targeted acute muscle injuries. The purpose of the present study was to provide and compare pre-season muscular strength and power profiles in professional and junior elite soccer players throughout the developmental years of 15-21. One original aspect of our study was that isokinetic data were considered alongside the past history of injury in these players. Fifty-seven elite and junior elite male soccer players were assigned to three groups: PRO, n=19; U-21, n=20 and U-17, n=18. Players benefited from knee flexor and extensor isokinetic testing consisting of concentric and eccentric exercises. A context of lingering muscle disorder was defined using statistically selected cut-offs. Functional performance was evaluated throughout a squat jump and 10 m sprint. The PRO group ran faster and jumped higher than the U-17 group (P<0.05). No significant difference in isokinetic muscle strength performance was observed between the three groups when considering normalized body mass parameters. Individual isokinetic profiles enabled the identification of 32/57 (56%) subjects presenting lower limb muscular imbalance. Thirty-six out of 57 players were identified as having sustained a previous major lower limb injury. Of these 36 players, 23 still showed significant muscular imbalance (64%). New trends in rational training could focus more on the risk of imbalance and implement antagonist strengthening aimed at injury prevention. Such an intervention would benefit not only athletes recovering from injury, but also uninjured players. An interdisciplinary approach involving trainers, a physical coach, and medical staff would be of interest to consider in implementing a prevention programme.

Analysis of sex-specific injury patterns and risk factors in young high-level athletes.

This study analyzed sex-specific injury patterns and risk factors in young athletes (n=256) from 12 sport disciplines practicing at the national or the international level in the Grand-Duchy of Luxembourg. Injury occurrence as a result of sport practice was analyzed retrospectively over the year 2006 using a standardized self-administered questionnaire. Overall incidence was not different between girls and boys (1.20 and 1.21 injuries/1000 athlete-hours, respectively), but in the context of team sport competition girls tended to be at a greater risk (rate ratio 2.05, P=0.053). Girls had a higher proportion of injuries in the ankle/foot region compared with boys (34.8% vs 16.8%). No sex-related differences were found regarding injury severity. Multivariate logistic regression (controlling for age and practice volume) revealed that girls' team sports were associated with a greater injury risk compared with individual sports [odds ratio (OR) of 4.76], while in boys this was observed for racket sports (OR=3.31). Furthermore, physical or emotional stress tended to be a specific risk factor in girls. There was a tendency for injury outside sports to be coupled to a higher injury risk in girls and boys. Consideration of sex-specific injury patterns and risk factors could be of importance for effective injury prevention.

The ability of isoinertial assessment to monitor specific training effects.

AIM: The aim of this study was to investigate the ability of isoinertial assessment to monitor training effects. Both parametric and curve analysis of the results were used to underline the specificity of maximal strength and maximal velocity resistance training methods. METHODS: Twenty-four untrained subjects were randomly assigned into three groups: a maximal strength-training group (heavy loads: 80% to 98% of the one repetition maximum [1-RM]), a maximal velocity-training group (light loads: 25% to 50% of 1-RM) and a control group. All the subjects were tested in bench press exercises before and after the 6-week training period. An isoinertial dynamometer was used to assess velocity and power at four increasing loads: 35%, 50%, 70% and 95% of the 1-RM load. Post-test protocol also included a trial at 105% of the 1-RM load. RESULTS: Isoinertial assessment demonstrated for both training groups significant gains at each load. Some specific adaptations appeared: strength training presented a greater increase for average power (+49%, P<0.001) and average velocity (+48%, P<0.001) at 95% of 1-RM, while velocity training emerged as a more effective way to improve performance at 35% and 50% of 1-RM (+11 to 22%) in comparison with strength training (+7 to 12%). The analysis of power and velocity curves specified that strength training enhanced performance earlier in the movement, while velocity training extended the propulsive action at the end of movement. CONCLUSION: The original combination of parametric and curve isoinertial assessment appears to be a relevant method for monitoring specific training effects. The complementarity of both strength and velocity training programmes underlined in this study could lead to practical applications in profiling training programmes.

Influence of a dynamic seating habit on lumbar motor control in schoolchildren.

BACKGROUND: Adequate motor control is considered important for spinal stability and the prevention of low back pain in adulthood and in childhood. OBJECTIVE: Given that the sitting position can affect proprioception, this study aimed to evaluate the influence of using at school a triangular and dynamic cushion on schoolchildren's trunk motor control. METHODS: Thirty 8-year-old schoolchildren were randomized into a control group (n= 15) and a "cushion group" (n= 15), in which the children used the cushion for one year and a half. At the end of this period, a 3D-analysis was used to assess lumbar spine proprioception by means of a trunk repositioning task performed blindfolded in a seated position in two conditions (on a stable and on an unstable surface). RESULTS: The schoolchildren in the cushion group performed better at the trunk repositioning task (p= 0.02) and hold their lumbar lordosis (p= 0.03) better than the control children, in both conditions (stable and unstable). CONCLUSIONS: This preliminary study suggests that daily use of a triangular dynamic cushion has a beneficial impact on children's lumbar proprioception. Further studies are needed to confirm these results and investigate the effectiveness of its use to prevent low back pain in adulthood.