Didier Maquet

Pressure pain thresholds of tender point sites in patients with fibromyalgia and in healthy controls

Pressure pain threshold (PPT) is defined as the minimum force applied which induces pain. This measure has proven to be commonly useful in evaluating tenderness symptom. Our aim was to study the intra‐examiner reproducibility of PPT measurement, define cutoffs in normal groups, and compare these results with patients with fibromyalgia (FM). Fifty healthy females, 50 healthy males, and 20 patients with FM participated in the study. PPTs were assessed for 18 specific tender point sites by a dolorimeter. The intra‐individual coefficient of variation determined by a test—retestPPT measurement procedure with 3‐days interval reached, respectively, 17% and 13% in healthy females and males, versus 24% in patients with FM. PPTs were significantly lower in healthy females than in healthy males (p<0.01). Statistical analysis failed to show any differences between the dominant and nondominant side for both normal groups. PPTs were lower over all examined areas in patients with FM than those obtained in healthy females (p<0.000). Lower cutoff levels were calculated from normal values for all specific tender point sites. On average, 14 tender point sites in patients with FM were under the established lower cutoffs. In conclusion, pressure pain sensitivity was influenced by the anatomical localization of tender point and gender differences. Lowest PPTs were localized in trapezius, occiput, anterior cervical, and second rib. The reduction of total tender point score in patients with FM averaged 60% comparatively with normal values. PPT reproducibility and discrimination between the two groups were optimal for the gluteal and knee sites.

Muscle performance in patients with fibromyalgia

OBJECTIVES To compare muscle performance in women with fibromyalgia and in healthy women. PATIENTS AND METHODS Sixteen women with fibromyalgia syndrome (FMS) and 85 healthy women who were physically inactive or engaged in recreational sports underwent measurements of four parameters: maximal concentric isokinetic muscle strength of the knee extensors and flexors in the dominant limb, isometric grip strength on a Colin dynamometer, muscle fatigue resistance during 30 maximal concentric isokinetic contractions of the dominant knee flexors and extensors at 180 degrees angular velocity, and static endurance during posture maintenance. RESULTS All muscle variables were decreased in the FMS patients as compared to the controls. The decreases were more marked during aerobic than during anaerobic exercise. Mean decreases were 39% (P<0.001) for muscle strength, 40% (P<0.0001) for fatigue resistance, and 81% (P<0.0001) for static endurance. Pain during exercise as evaluated using a visual analog scale was more marked in the FMS patients. CONCLUSION This study of the three pathways supplying energy to muscle confirms that muscle function is globally impaired in FMS patients. The results suggest that the impairment predominates on aerobic processes.

Explosive Strength Imbalances in Professional Basketball Players

CONTEXT Despite the high rate of lower limb injuries in basketball players, studies of the dominant-limb effect in elite athletes often neglect injury history. OBJECTIVE To determine lower limb explosive-strength asymmetries in professional basketball players compared with junior basketball players and control participants. DESIGN Cohort study. SETTING Academic medical institution. PATIENTS OR OTHER PARTICIPANTS 15 professional basketball players, 10 junior basketball players, and 20 healthy men. MAIN OUTCOME MEASURE(S) We performed an isokinetic examination to evaluate the knee extensor (Ext) and flexor (Fl) concentric peak torque at 60 degrees .s(-1) and 240 degrees .s(-1) and (Fl only) eccentric peak torque at 30 degrees .s(-1) and 120 degrees .s(-1). Functional evaluation included countermovement jump, countermovement jump with arms, 10-m sprint, single-leg drop jump, and single-leg, 10-second continuous jumping. Variables were compared among groups using analysis of variance or a generalized linear mixed model for bilateral variables. RESULTS The 2 groups of basketball players demonstrated better isokinetic and functional performances than the control group did. No differences in functional or relative isokinetic variables were noted between professional and junior basketball players. Professional players with a history of knee injury failed to reach normal knee extensor strength at 60 degrees .s(-1). Knee Ext (60 degrees .s(-1)) and Fl (eccentric 120 degrees .s(-1)) torque values as well as 10-second continuous jumping scores were higher in those professional players without a history of knee injury than those with such a history. Compared with the group without a history of knee injury, the group with a history of knee injury maintained leg asymmetry ratios greater than 10% for almost all isokinetic variables and more than 15% for unilateral functional variables. CONCLUSIONS The relative isokinetic and functional performances of professional basketball players were similar to those of junior players, with no dominant-side effect. A history of knee injury in the professional athlete, however, was reflected in bilateral isokinetic and functional asymmetries and should be considered in future studies of explosive strength.

Gait analysis in elderly adult patients with mild cognitive impairment and patients with mild Alzheimer’s disease: simple versus dual task: a preliminary report

Background/Aims:  The aim of this study was to assess gait characteristics during simple and dual task in patients with mild cognitive impairment (MCI) and compare them with those of healthy elderly subjects and mild Alzheimer’s disease (AD) patients.

Translation validation of a new back pain screening questionnaire (the STarT Back Screening Tool) in French

BackgroundLow back pain (LBP) is a major public health problem and the identification of individuals at risk of persistent LBP poses substantial challenges to clinical management. The STarT Back questionnaire is a validated nine-item patient self-report questionnaire that classifies patients with LBP at low, medium or high-risk of poor prognosis for persistent non-specific LBP. The objective of this study was to translate and cross-culturally adapt the English version of the STarT Back questionnaire into French.MethodsThe translation was performed using best practice translation guidelines. The following phases were performed: contact with the STarT Back questionnaire developers, initial translations (English into French), synthesis, back translations, expert committee review, test of the pre-final version on 44 individuals with LBP, final version.ResultsThe linguistic translation required minor semantic alterations. The participants interviewed indicated that all items of the questionnaire were globally clear and comprehensible. However, 6 subjects (14%) wondered if two questions were related to back pain or general health. After discussion within the expert committee and with the developer of the STarT Back tool, it was decided to modify the questionnaire and to add a reference to back pain in these two questions.ConclusionsThe French version of the STarT Back questionnaire has been shown to be comprehensible and adapted to the French speaking general population. Investigations are now required to test the psychometric properties (reliability, internal and external validity, responsiveness) of this translated version of the questionnaire.

Development and validation of an accelerometer-based method for quantifying gait events

An original signal processing algorithm is presented to automatically extract, on a stride-by-stride basis, four consecutive fundamental events of walking, heel strike (HS), toe strike (TS), heel-off (HO), and toe-off (TO), from wireless accelerometers applied to the right and left foot. First, the signals recorded from heel and toe three-axis accelerometers are segmented providing heel and toe flat phases. Then, the four gait events are defined from these flat phases. The accelerometer-based event identification was validated in seven healthy volunteers and a total of 247 trials against reference data provided by a force plate, a kinematic 3D analysis system, and video camera. HS, TS, HO, and TO were detected with a temporal accuracy ± precision of 1.3 ms ± 7.2 ms, -4.2 ms ± 10.9 ms, -3.7 ms ± 14.5 ms, and -1.8 ms ± 11.8 ms, respectively, with the associated 95% confidence intervals ranging from -6.3 ms to 2.2 ms. It is concluded that the developed accelerometer-based method can accurately and precisely detect HS, TS, HO, and TO, and could thus be used for the ambulatory monitoring of gait features computed from these events when measured concurrently in both feet.

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.

Validity and reliability of the French version of the STarT Back screening tool for patients with low back pain.

Study Design. Observational prospective study. Objective. Our objective was to assess the reliability and validity of the French version of the Keele STarT Back Screening Tool (SBST). Summary of Background Data. The SBST is a recently validated tool developed to identify subgroups of patients with low back pain (LBP) to guide early secondary prevention in primary care. Methods. Outpatients 18 years or older with LBP, attending a rehabilitation center, a back school, a private physiotherapy unit, or a fitness center were included. Patients were assessed through the SBST, Roland-Morris Disability Questionnaire, Örebro Musculoskeletal Pain Screening Questionnaire, Medical Outcomes Survey Short Form-36 questionnaire, and a pain visual analogue scale. Test-retest reliability was assessed with Kappa score or the intraclass correlation coefficient, internal consistency of the Psychological subscale with the Cronbach &agr; coefficient, construct validity with the Spearman correlation coefficient, and floor and ceiling effects by percentage frequency of lowest or highest possible score achieved by respondents. Results. One hundred eight patients with LBP were included. The test-retest reliability of the SBST total score was excellent with an intraclass correlation coefficient of 0.90 (0.81–0.95). The Cronbach &agr; coefficient was 0.73 showing a good internal consistency for the Psychological subscale. High Spearman correlation coefficients of 0.74 between SBST and Roland-Morris Disability Questionnaire, and 0.74 between the SBST and Örebro Musculoskeletal Pain Screening Questionnaire were observed. As expected, low-to-moderate correlations were observed between the SBST total score and some dissimilar measures of the Short-Form 36. The lowest possible SBST score was observed for 8 patients (7.4%), whereas only 3 patients (2.8%) had the highest possible SBST score. Conclusion. The French version of the SBST is a reliable and valid questionnaire consistent with the original English version. Therefore, this new version may help French-speaking clinicians and scientists to stratify patients with LBP. Level of Evidence: 2

Effects of 3 months of short sessions of controlled whole body vibrations on the risk of falls among nursing home residents

BackgroundFatigue, lack of motivation and low compliance can be observed in nursing home residents during the practice of physical activity. Because exercises should not be too vigorous, whole body vibration could potentially be an effective alternative. The objective of this randomized controlled trial was to assess the impact of 3-month training by whole body vibration on the risk of falls among nursing home residents.MethodsPatients were randomized into two groups: the whole body vibration group which received 3 training sessions every week composed of 5 series of only 15 seconds of vibrations at 30 Hz frequency and a control group with normal daily life for the whole study period. The impact of this training on the risk of falls was assessed blindly by three tests: the Tinetti Test, the Timed Up and Go test and a quantitative evaluation of a 10-second walk performed with a tri-axial accelerometer.Results62 subjects (47 women and 15 men; mean age 83.2 ± 7.99 years) were recruited for the study. No significant change in the studied parameters was observed between the treated (n=31) and the control group (n=31) after 3 months of training by controlled whole-body-vibrations. Actually, the Tinetti test increased of + 0.93 ± 3.14 points in the treated group against + 0.88 ± 2.33 points in the control group (p = 0.89 when adjusted). The Timed Up and Go test showed a median evolution of - 1.14 (− 4.75-3.73) seconds in the treated group against + 0.41 (− 3.57- 2.41) seconds in the control group (p = 0.06). For the quantitative evaluation of the walk, no significant change was observed between the treated and the control group in single task as well as in dual task conditions.ConclusionsThe whole body vibration training performed with the exposition settings such as those used in this research was feasible but seems to have no impact on the risk of falls among nursing home residents. Further investigations, in which, for example, the exposure parameters would be changed, seem necessary.Trial registrationTrial registration number: NCT01759680

Gait feature extraction in Parkinson's disease using low-cost accelerometers

The clinical hallmarks of Parkinsons disease (PD) are movement poverty and slowness (i.e. bradykinesia), muscle rigidity, limb tremor or gait disturbances. Parkinsons gait includes slowness, shuffling, short steps, freezing of gait (FoG) and/or asymmetries in gait. There are currently no validated clinical instruments or device that allow a full characterization of gait disturbances in PD. As a step towards this goal, a four accelerometer-based system is proposed to increase the number of parameters that can be extracted to characterize parkinsonian gait disturbances such as FoG or gait asymmetries. After developing the hardware, an algorithm has been developed, that automatically epoched the signals on a stride-by-stride basis and quantified, among others, the gait velocity, the stride time, the stance and swing phases, the single and double support phases or the maximum acceleration at toe-off, as validated by visual inspection of video recordings during the task. The results obtained in a PD patient and a healthy volunteer are presented. The FoG detection will be improved using time-frequency analysis and the system is about to be validated with a state-of-the-art 3D movement analysis system.