This paper presents some hypotheses concerning the identification of homogeneous subgroups among fibromyalgia (FM) patients in order to improve the management of the disease. It also reviews the available literature about this subject. Three methods for subgrouping are discussed according to clinical features, biomarkers, and gait analysis. Clinical subgrouping based on cluster analysis has been used for the identification of homogeneous subgroups of patients and, more recently, homogeneous clinical features. So far, longitudinal studies using clinical subgroups to direct treatment and predict outcome are still required. Biomarkers in FM, which is a neurobiological disease, are of promising interest, nevertheless currently, none of them can be used to subgroup FM patients. Due to the fact that cortical and subcortical mechanisms of gait control share some cognitive functions which are involved in FM, gait markers have been proposed to evaluate and to subgroup FM patients, in clinical settings. Three out of 4 core FM symptoms are linked to gait markers. Kinesia measured by means of cranio-caudal power is correlated to pain, and could be proposed to assess pain behavior (kinesiophobia). Stride frequency, which is linked to physical component, allows the identification of a hyperkinetic subgroup. Moreover, SF has been correlated to fatigue during the 6 minute walking test. Stride regularity, which expresses the unsteadiness of gait, is correlated to cognitive dysfunction in FM. Decreased stride regularity allows the recognition of a homogeneous subgroup characterized by an increased anxiety and depression, and decreased cognitive functions. These results need further studies to be validated and so used in the daily clinical practice.

AIM:The purpose of this study was to analyze the continuous changes in stride patterns of athletes running at speed elicited VO(2max).METHODS:Six male sub-elite middle-distance runners carried out a constant track running test to exhaustion (time to exhaustion: 409+/-71 s) at their maximal aerobic speed (17.4+/-1.1 km.h(-1)). The body accelerations were measured with a triaxial accelerometer fixed at the low back. A set of variables was computed from the accelerometer output: stride frequency, stride symmetry and regularity, signal energies and impulses in each axis and the integral of the total acceleration vector. An ANOVA with repeated measures was performed to test the changes of these variables during the three times: the onset point, midway point and end point of exercise.RESULTS:The following changes were observed: the regularity index which describes the similarity of crania-caudal movements over successive strides, decreased significantly between the start and the end of the test (309.9 to 274.5; P<0.05). During the same time, the media-lateral impulse (4.69%BW.s to 5.71%BW.s; P<0.001; BW: body weight) and signal energy (1.40 G(2).s to 2.06 G(2).s; P<0.001; G=9.81 m.s(-2)) increased significantly.CONCLUSIONS:The changes in medio-lateral axis (increase of energy expenditure which is not useful for propulsion) and in the regularity index (modifications in the temporal-spatial periodicity of the running cycle) could be considered as early alterations of running pattern when the athletes got fatigued.

The objective of this study was to analyse stabilized gait disorders in newly diagnozed Parkinson patients using an accelerometric device, which had been previously validated for human locomotion analysis (Auvinet et al., 1999), and to compare Parkinson's gait variables with those obtained in a matched normal population (same gender, age, height and weight). The patient group included 22 subjects (women: 9, men: 13; age: 69+/-9 y; height: 164+/-9 cm; weight: 71+/-15 kg) with motor score from 4 to 59 (mean: 23.5+/-3.0). Gait analysis system included two accelerometers held over the middle of the low back by means of a semi-elastic belt, cranio-caudal and side to side accelerations were recorded at a frequency of 50 Hz. Subjects were asked to walk at their own speed along a straight 40 meter long corridor. A 20 second period of stabilized walking was used to calculate stride frequency, step symmetry, stride regularity and cranio-caudal activity (related to hypokinesia). The walking speed was measured with an electronic stop watch. Parkinson's gait was characterized by a reduction of walking velocity (p<0.0001) which was explained by reduction of stride frequency (p<0.001) and step length (p<0.001), but mainly we noticed a reduction of walking regularity (p<0.0001) and of the cranio-caudal activity (p<0.0001). These two last variables were strongly correlated to the motor score ((r=-0.59 (p<0.01); r=-0.65 (p<0.003), respectively)). In conclusion regularity and cranio-caudal activity appeared as the most interesting variables to characterize stabilized Parkinson's gait.

The objective of this study was to measure gait abnormalities in elderly fallers with the Locometrix™ gait-analysis system. This accelerometric device provided the following gait variables: walking speed and stride frequency, length, symmetry, and regularity. The variables were analyzed over a 20-s period of stable walking on a flat track of 40 m. Participants were 20 elderly patients hospitalized for falls (mean age 80.8 ± 5.0 years) and 33 older adults living at home (mean age 77.2 ± 6.5 years). All gait variables were found to be significantly lower in the faller group (p < .05). The lower gait speed, stride length, and stride frequency were previously recognized as nonrelevant in predicting the risk of falling, whereas lower stride symmetry was related to an underlying pathology and lower stride regularity was correlated to the risk of falls. The Locometrix appears to be well suited to measure gait regularity in routine practice.

The purpose of this study was to analyse the strides of middle distance runners using a new ambulatory gait analysis system adapted to field and track conditions. Nine middle distance runners performed a locomotor test which consisted of three step-tests close to their anaerobic threshold with an increase of 0.5 m.s-1 between each step-test. The increase in velocity was correlated to an increase in stride length (p< 0.001), and a decrease of stride symmetry and regularity (p< 0.05) and a decrease of left and right stance duration (p< 0.05). Wavelet analysis provided a pictorial description of gait particularities which could be of interest for trainers or practitioners.

Summary Aim: The high incidence of patients who have suffered from falls in the Laval hospital prompted the establishment to create a falling study group which included general and hospital practitioners, and a laboratory specializing in gait analysis. Methods: Three studies were carried out : Clinical comparison between fallers and elderly non-fallers (n = 68 and 42 respectively), Gait analysis: reference data for normal subjects (138 men and 144 women between 20 to 98 years old) obtained with an accelerometric device ; Gait abnormalities in elderly fallers (n = 20) compared to a control group (n = 33). Results: Clinical comparison between fallers and elderly non-fallers showed that there were few differences related to the pathologies of the subjects; however daily living activities, Tinetti and monopodal tests were highly im

We collected gait analysis data for 282 healthy adults and elderly people (144 women and 138 men aged 20–98) using an accelerometric device, whose reproducibility (intra-tester and inter-testers) has been validated for gait studies. The subjects walked at their own speed along a corridor (40 m). Stride frequency (SF) (after correction for height), step symmetry (Sym), stride regularity (Reg), and vertical harmonic (slope) were all independent of age or gender. The median-lateral harmonic (slope) (MSH) was influenced by gender, but not by age. Other variables (walking speed, stride length (SL), cranial–caudal activity and raw accelerations at heel contact, mid-stance and initial push-off) were dependent on gender and age. They were higher in men than in women, and began to decrease during the sixth decade in men and the seventh decade in women. The raw acceleration at foot flat was independent of gender but was influenced by age. This accelerometric device is easy to use and requires no specialized equipment and could be used to analyze walking in clinical practice.

ROULEAU, F., et al. : Echocardiographic Assessment of the Interventricular Delay of Activation and Correlation to the QRS Width in Dilated Cardiomyopathy. The aim of the study was to define criteria for left ventricular pacing in dilated cardiomyopathy (DCM) using an echocardiographic evaluation of interventricular electromechanical delay (IMD) and a correlation of IMD to QRS duration. Standard 12‐lead ECG and echocardiography with pulsed Doppler tissue imaging (DTI) were recorded in 35 DCM patients ( mean age 58 ± 11 years ) with QRS duration from narrow (80 ms) to broad (222 ms) patterns. The time for left ventricular activation was evaluated from the onset of QRS to the onset of aortic flow (Q‐Ao) by standard pulsed Doppler (SP) or to the onset of mitral annulus systolic wave (Q‐Mit) (DTI). The time for right ventricular activation was determined from the onset of QRS to the onset of pulmonary flow (Q‐Pulm) (SP) or to the onset of tricuspid annulus systolic wave (Q‐Tri) (DTI). (Q‐Ao)–(Q‐Pulm) and (Q‐Mit)–(Q‐Tri) determined IMD for each method, respectively. QRS width and IMD showed correlation coefficients of r = 0.86 ([Q‐Ao]‐[Q‐Pulm]) and r = 0.82 ([Q‐Mit]‐[Q‐Tri]) ( P ≤ 0.001 ). Mean IMD of 77 ± 15 ms (SP) and 88 ± 26 ms (DTI) were noted for QRS width above 150 ms. Left ventricle delayed activation was positively correlated to QRS widening with both methods, ( r = 0.90, [Q‐Ao] ), ( r = 0.83, [Q‐Mit] ) ( P ≤ 0.001 ). In conclusion, QRS duration is a good marker of an interventricular mechanical asynchrony. According to IMD correction, left ventricular pacing may be mainly proposed to symptomatic DCM patients with QRS duration > 150 ms.