Biomedical subjects

Jean-Michel Crielaard

Publications and source records attributed to Jean-Michel Crielaard.

10 recordsLinked to original sources

PubMed2007

An isokinetic eccentric programme for the management of chronic lateral epicondylar tendinopathy.

BACKGROUND: Lateral epicondylitis represents a frequent overuse injury. In spite of many conservative treatment procedures, prolonged symptoms and relapse are frequently observed. OBJECTIVE: To compare the outcome of patients performing an isokinetic eccentric training with that of age-, gender-, activity-matched patients receiving a non-strengthening classical rehabilitation. METHODS: Ninety-two patients with unilateral chronic lateral epicondylar tendinopathy (mean duration of symptoms 8+/-3 months) were assigned either to a control group (n = 46) or to an eccentrically trained group (n = 46). The control group underwent a passive standardised rehabilitation programme that excluded strengthening exercises. In addition to this programme, the trained group also performed eccentric exercises based on the repetitive lengthening of the active musculo-tendinous unit. The latter exercises started with submaximal contraction intensity and slow speed movement. Modalities were progressively intensified (increase in intensity contraction and speed movement) over a long period of treatment. Programme effectiveness was assessed through pain score evaluation, a disability questionnaire, muscle strength measurement and ultrasonographic examination. RESULTS: Compared to the non-strengthening control group, the following observations were made in the eccentrically trained group: (1) a significantly more marked reduction of pain intensity, mainly after one month of treatment; (2) an absence of strength deficit on the involved side through bilateral comparison for the forearm supinator and wrist extensor muscles; (3) an improvement of the tendon image as demonstrated by decreasing thickness and a recovered homogenous tendon structure; and (4) a more marked improvement in disability status during occupational, spare time and sports activities. CONCLUSION: These results highlight the relevance of implementing isokinetic adapted eccentric training in the management of chronic lateral epicondylar tendinopathy.

Adult↗

PubMed2006

Spinal muscle evaluation in healthy individuals and low-back-pain patients: a literature review.

This article reviews available techniques for spinal muscle investigation, as well as data on spinal muscles in healthy individuals and in patients with low back pain. In patients with chronic low back pain, medical imaging studies show paraspinal muscle wasting with reductions in cross-sectional surface area and fiber density. In healthy individuals, the paraspinal muscles contain a high proportion of slow-twitch fibers (Type I), reflecting their role in maintaining posture. The proportion of Type I fibers is higher in females, leading to better adaptation to aerobic exertion compared to males. Abnormalities seen in paraspinal muscles from patients with chronic low back pain include marked Type II fiber atrophy, conversion of Type I to Type II fibers, and an increased number of nonspecific abnormalities. Limited data are available from magnetic resonance spectroscopy used to investigate muscle metabolism and from near infrared spectroscopy used to measure oxygen uptake by the paraspinal muscles. Surface electromyography in patients with chronic low back pain shows increased paraspinal muscle fatigability, often with abolition of the flexion-relaxation phenomenon.

Electromyography↗

PubMed2006

Spinal muscle evaluation using the Sorensen test: a critical appraisal of the literature.

The first test for evaluating the isometric endurance of trunk extensor muscles was described by Hansen in 1964. In 1984, following a study by Biering-Sorensen, this test became known as the "Sorensen test" and gained considerable popularity as a tool reported to predict low back pain within the next year in males. The test consists in measuring the amount of time a person can hold the unsupported upper body in a horizontal prone position with the lower body fixed to the examining table. This test has been used in many studies, either in its original version or as variants. Although its discriminative validity, reproducibility, and safety seem good, debate continues to surround its ability to predict low back pain; in addition, the gender-related difference in position-holding time remains unexplained and the influence of body weight unclear. A contribution of the hip extensor muscles to position holding has been established, but its magnitude remains unknown. The influence of personal factors such as motivation complicates the interpretation of the results. Despite these drawbacks, the Sorensen test has become the tool of reference for evaluating muscle performance in patients with low back pain, most notably before and after rehabilitation programs.

Exercise Test↗

PubMed2006

Avocado/soybean unsaponifiables prevent the inhibitory effect of osteoarthritic subchondral osteoblasts on aggrecan and type II collagen synthesis by chondrocytes.

OBJECTIVE: To determine the effects of avocado/soybean unsaponifiables (ASU) on osteoblast-induced dysregulation of chondrocyte metabolism. METHODS: Human chondrocytes were isolated from osteoarthritis (OA) cartilage and cultured in alginate beads for 4 or 10 days in the absence or presence of osteoblasts isolated from nonsclerotic (NSC) or sclerotic (SC) zones of OA subchondral bone plate in monolayer. Before co-culture, osteoblasts were incubated or not with 10 microg/ml ASU for 72 hours. Aggrecan, type II collagen, matrix metalloproteinase-3 (MMP-3) and MMP-13, tissue inhibitor of metalloproteinase (TIMP-1), transforming growth factor-beta1 (TGF-beta1) and TGF-beta3, inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2) mRNA levels in chondrocytes were quantified by RT-PCR. Aggrecan, osteocalcin, TGF-beta1, interleukin 1beta (IL-1beta), and IL-6 production were assayed by immunoassays. RESULTS: In co-culture, SC osteoblasts induced a significant inhibition of matrix protein production and a significant increase of MMP synthesis by chondrocytes. In contrast, SC osteoblasts did not modify TIMP-1, TGF-beta1 and TGF-beta3, iNOS, or COX-2 mRNA levels in chondrocytes. The pretreatment of SC osteoblasts with ASU fully prevented the inhibitory effects of SC osteoblasts on matrix component production, and even significantly increased type II collagen mRNA level over the control (chondrocytes alone) value. In contrast, pretreatment of SC osteoblasts with ASU did not significantly modify the expression of MMP, TIMP-1, TGF-beta1, TGF-beta3, iNOS, or COX-2 gene by chondrocytes. CONCLUSION: ASU prevent the osteoarthritic osteoblast-induced inhibition of matrix molecule production, suggesting that this compound may promote OA cartilage repair by acting on subchondral bone osteoblasts. This finding constitutes a new mechanism of action for this compound, known for its beneficial effects on cartilage.

Aged↗

PubMed2005

Factors correlated with volleyball spike velocity.

BACKGROUND: Spike effectiveness represents a determining element in volleyball. To compete at a high level, the player must, in particular, produce a spike characterized by a high ball velocity. HYPOTHESIS: Some muscular and physical features could influence ball velocity during the volleyball spike. STUDY DESIGN: Descriptive laboratory study. METHODS: A total of 19 male volleyball players from the 2 highest Belgian national divisions underwent an isokinetic assessment of the dominant shoulder and elbow. Ball velocity performance (radar gun) during a spike test, morphological feature, and jump capacity (ergo jump) of the player were measured. We tested the relationship between the isokinetic parameters or physical features and field performances represented by spike velocity. We also compared first-division and second-division player data. RESULTS: Spike velocity correlated significantly with strength performance of the dominant shoulder (internal rotators) and of the dominant elbow (flexors and extensors) in the concentric mode. Negative correlations were established with the concentric external rotator on internal rotator ratio at 400 deg/s and with the mixed ratio (external rotator at 60 deg/s in the eccentric mode on internal rotator at 240 deg/s in the concentric mode). Positive correlations appeared with both the volleyball players' jump capacity and body mass index. First-division players differed from second-division players by higher ball velocity and increased jump capacity. CONCLUSION: Some specific strength and physical characteristics correlated significantly with spike performance in high-level volleyball practice. CLINICAL RELEVANCE: Our results could provide useful information for training management and propose some reflections on injury prevention.

Adult↗

PubMed2004

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-retest PPT 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.

Adult↗

PubMed2002

[Dorsal and lumbar paraspinal electromyographic study. Multi-MUP analysis and drawing up normal values in a reference population].

OBJECTIVE: The aim of this study was to contribute to draw up reference values relating to electromyographic (EMG) parameters in dorsal and lumbar paraspinal muscles. MATERIALS AND METHODS: 75 healthy subjects without back pain underwent electromyography of multifidus bundles, which are innervated uni-segmentally by the dorsal ram of the spinal nerve. T8, L3, L4, L5 and S1 myotomes were systematically explored. Output variables were spontaneous denervation activity and quantitative EMG data obtained by multi-MUP (Motor Unit action Potential) analysis. RESULTS: No abnormal insertional or spontaneous activity (such as fibrillation, positive sharp waves or fasciculation) was recorded at rest. Neither sex nor age influenced motor unit action potential features in our series. Reference values were drawn up for T8 and L5 segmental levels using the mean values of 20 motor unit potentials in each patient studied, the reference interval being defined by the lower and the upper outlier limits on individual values. CONCLUSION: This study offers reference data to electromyographers to help better identifying possible myogenic or neurogenic pathological changes, especially in lumbosacral radiculopathies.

Adult↗

PubMed2002

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.

Adult↗

PubMed2002

Blood flow variation in human muscle during electrically stimulated exercise bouts.

OBJECTIVES: To evaluate, with a high spatial resolution, the blood flow variations in human skeletal muscle during neuromuscular electric stimulation (NMES) and hence to gain better understanding of the mechanisms of muscle spatial recruitment during NMES. DESIGN: One thigh was submitted to 3 stimulation bouts of different durations (S1=4min, S2=8min, S3=12min) with a workload corresponding to 10% of quadriceps maximal isometric voluntary torque. SETTING: A cyclotron research center at a Belgian university. PARTICIPANTS: Ten healthy male volunteers. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants were studied with positron emission tomography and H(2)(15)O. Tissue blood flow was evaluated during the last 4 minutes of each stimulation bout in multiple regions of interest (ROIs) selected in the transverse section of the stimulated thigh. RESULTS: Mean tissue blood flow was significantly lower during S1 (5.9+/-1.3mL. min(-1). 100g(-1)) than during S2 (10.6+/-3.4mL. min(-1). 100g(-1)) and S3 (11.6+/-3.7mL. min(-1). 100g(-1)) (P<.05). For each ROI, an arbitrary tissue blood flow activation level of 5mLmin(-1)100g(-1) was fixed. The mean percentage of activated ROIs reached 42.4%, 62.7%, and 63.6% during S1, S2, and S3, respectively. Between S1 and S3, the newly recruited ROIs were preferentially located far from the electrode. CONCLUSION: During NMES, new muscular regions situated far from the stimulation site are recruited. These recruitment mechanisms are particular and contrast with the recruitment of motor units seen during voluntary contraction.

Adult↗

PubMedDate not supplied

Hamstring muscle strain recurrence and strength performance disorders.

We determined the frequency of strength disorders in 26 athletes with a history of hamstring muscle injury and recurrent strains and discomfort. We also assessed the effectiveness of rehabilitation to correct muscle performance. After concentric and eccentric isokinetic assessment, 18 athletes were found to have strength deficits, as determined by statistically selected cutoffs of peak torque, bilateral differences, and the flexors/quadriceps ratio. The discriminating character of the eccentric trial was demonstrated, combining a preferential eccentric peak torque deficit and a significant reduction of the mixed eccentric flexors/concentric quadriceps ratio. The athletes with muscle imbalances followed a rehabilitation program individually adapted from their strength profile. Treatment length was from 10 to 30 sessions and resulted in isokinetic parameter normalization in 17 of 18 subjects. Isokinetically corrected subjects were observed for 12 months after return to athletics. None sustained a clinically diagnosed hamstring muscle reinjury. Subjective intensity of pain and discomfort were significantly reduced, and they all returned to their prior level of competition. These results demonstrate that persistent muscle strength abnormalities may give rise to recurrent hamstring injuries and discomfort. An individualized rehabilitation program emphasizing eccentric training based on specific deficits contributes to a decrease in symptoms on return to sports.

Adult↗