Investigation of reaction force magnitude and orientation during supine thoracic thrust manipulation applied to intervertebral and costovertebral regions.

BACKGROUND: Spinal manipulative techniques are commonly used in manual therapies but quantified descriptive and reliability data are lacking considering supine thoracic thrust manipulation. OBJECTIVES: The purpose of this study is to explore and compare kinetic parameters during supine thoracic thrust manipulation performed at two different thoracic regions. Intra-rater task repeatability and influence of practitioners were estimated. DESIGN: Exploratory and agreement study. METHODS: Kinetic parameters were assessed by examining reaction force magnitude and orientation (on the basis of the zenithal angle) using force platforms. Manipulative procedure (consisting in the application of 3 preloads followed by one thrust adjustment) at both intervertebral and costovertebral region was performed by different practitioners at three sessions. Application of thrust was allowed for experienced practitioners only. Preload force, peak force magnitude and vector force orientation were compared between anatomical sites, sessions and practitioners, and bias with limit of agreement were estimated. RESULTS: Repeatability analysis showed that practitioners achieved similar preload and peak force independent of the session, with comparable force orientation. Differences between practitioners were observed for preload and peak force but not regarding the zenithal angle during the thrust phase. CONCLUSIONS: The present study is the first that explores kinetic parameters for supine thoracic thrust manipulation applied on two different regions of the thorax. Results confirm consistency of performance among practitioners for supine manipulative techniques at intervertebral and costovertebral region. While task repeatability was confirmed, several differences were observed between practitioners. Further investigations would examine velocity, acceleration and potential neurophysiological effect of such manipulative technique.

Assessment of cervical stiffness in axial rotation among chronic neck pain patients: A trial in the framework of a non-manipulative osteopathic management.

BACKGROUND: Cervical stiffness is a clinical feature commonly appraised during the functional examination of cervical spine. Measurements of cervical stiffness in axial rotation have not been reported for patients with neck pain. The purpose of this study was to investigate cervical spine stiffness in axial rotation among neck pain patients and asymptomatic subjects, and to analyze the impact of osteopathic management. METHODS: Thirty-five individuals (17 patients) were enrolled. Measurements were carried out for left-right axial rotation using a torque meter device, prior and after intervention. Passive range of motion, stiffness, and elastic-and neutral zone magnitudes were analyzed. Pain intensity was also collected for patients. The intervention consisted in one single session of non-manipulative osteopathic treatment performed in both groups. FINDINGS: A significant main effect of intervention was found for total range of motion and neutral zone. Also, treatment by group interaction was demonstrated for neutral-, elastic zone, stiffness in right axial rotation, and for total neutral zone. Significant changes were observed in the clinical group after intervention, indicating elastic zone decrease and neutral zone increase. In contrast, no significant alteration was detected for the control group. INTERPRETATIONS: Stiffness characteristics of the cervical spine in axial rotation are prone to be altered in patients with neck pain, but seem to be relieved after a session of non-manipulative manual therapeutic techniques. Further investigations, including randomized clinical trials with various clinical populations and therapeutic modalities, are needed to confirm these preliminary findings.

Effect of neurodynamic mobilization on fluid dispersion in median nerve at the level of the carpal tunnel: A cadaveric study.

OBJECTIVES: To evaluate the effect of neurodynamics mobilization (NDM) on an artificially induced edema in the median nerve at the level of the carpal tunnel in unembalmed cadavers and to assess whether NDM tensioning techniques (TT) and NDM sliding techniques (SLT) induce similar effects on intraneural fluid dispersion. DESIGN: Fourteen upper extremities of seven unembalmed cadavers were used in this study. A biomimetic solution was injected directly under the epineurium of the median nerve at the level of the proximal transverse carpal ligament. The initial dye spread was allowed to stabilize and measured with a digital caliper. Tensioning and sliding techniques were applied following a randomized crossover design to each upper extremity and were performed for a total of 5 min each. Post-intervention dye spread measurements were taken after each technique. RESULTS: After the first mobilization, the mean longitudinal dye spread (7.5 ± 6.6 mm) was significantly greater (p = 0.024) compared to the stabilized dye spread. There was a significant longitudinal diffusion effect with both, TT (p = 0.018) and SLT (p = 0.016), with no statistically significant difference between techniques (p = 0.976). The order in which techniques were administered did not influence the diffusion. CONCLUSION: Five minute of passive NDM in the form of tensioning or sliding technique induced significant fluid dispersion in the median nerve at the carpal tunnel of unembalmed human cadavers. This study provides support for clinical mechanism of NDM in reducing intraneural edema.

Analysis of the upper cervical spine stiffness during axial rotation: A comparative study among patients with tension-type headache or migraine and asymptomatic subjects.

BACKGROUND: Many studies reported the implication of the cervical musculoskeletal system in patients with tension type headache and migraine. The objective of this study is to investigate the upper cervical spine stiffness features in axial rotation among headache patients in comparison with a healthy population. METHODS: 48 subjects including 30 migraine patients with/without aura and 18 patients with tension-type headache, aged between 18 and 60years (mean 36, SD 11years) have been evaluated. Stiffness measurements were carried out for passive axial rotation using a torque meter device. The flexion-rotation test was used to emphasize assessment of the upper cervical spine. FINDINGS: Neither the stiffness nor the neutral zone varies between different populations studied. Passive range of motion in axial rotation is unilaterally reduced in symptomatic subjects (p=0.001). Considering the elastic zone, right and left motion magnitude was significantly lower for clinical groups compared to the control group. INTERPRETATION: Stiffness seems not to be altered among tension type headache and migraine patients. However, patients seem prone to display a larger right-left asymmetry of axial rotation and a reduction in the motion range tolerance, emphasizing the likely link between the cervical discomfort and these pathologies. Any difference is observed in the elastic behavior of the upper cervical spine between the two primary headache populations. However, further investigations are needed to confirm these previous results taking various specific clinical characteristics into consideration.

In vitro biomechanical study of femoral torsion disorders: effect on moment arms of thigh muscles.

BACKGROUND: Lower limb torsion disorders have been considered as a factor inducing gonarthrosis and the three-dimensional effect of the surgical correction is not well reported yet. This paper reports an in vitro study aiming at quantifying the relationships between experimental femoral torsion disorders and moment arms of thigh muscles. METHODS: Five unembalmed lower limbs were used and fixed on an experimental jig. Muscles were loaded and 6 Linear Variable Differential Transformers were used to measure tendon excursions. Experimental osteotomies were performed to simulate torsions by steps of 6° up to 18°. Moment arms of the main thigh muscles were estimated by the tendon excursion method during knee flexion. FINDINGS: Moment arms of the tensor of fascia latae, the gracilis and the semitendinosus were significantly influenced by experimental conditions while the rectus femoris, the biceps femoris and the semimembranosus did not show modifications. Medial femoral torsion decreased the moment arm of both the gracilis and the semimembranosus. Opposite changes were observed during lateral femoral torsion. The moment arm of the tensor of fascia latae decreased significantly after 30° of knee flexion for 18° of medial femoral torsion. INTERPRETATION: Our results showed that medial and lateral femoral torsion disorders induced alterations of the moment arms of the muscles located medially to the knee joint when applied in aligned lower limbs. These results highlight a potential clinical relevance of the effect of femoral torsion alterations on moment arms of muscles of the thigh which may be related, with knee kinematics modifications, to the development of long-term knee disease.

In vitro biomechanical study of femoral torsion disorders: effect on femoro-tibial kinematics.

BACKGROUND: Gonarthrosis is a degenerative disease mainly found in elderly persons. Frontal plane deviations are known to induce lateral and medial gonarthrosis. Nevertheless, patients suffer from gonarthrosis without frontal deviations. Lower limb torsions disorders have been considered as a factor inducing lateral and medial gonarthrosis. This paper reports an in vitro study aiming at quantifying the relationships between experimental femoral torsion disorders and femoro-tibial kinematics. METHODS: Five fresh-frozen lower limbs were used. Specimens were fixed on an experimental jig and muscles were loaded. A six-degree-of-freedom Instrumented Spatial Linkage was used to measure femoro-tibial kinematics. Experimental femoral osteotomies were performed to simulate various degrees of medial and lateral torsion. Internal tibial rotation, abduction/adduction and proximo-distal, medio-lateral and antero-posterior translations were measured during knee flexion. FINDINGS: Internal tibial rotation and abduction/adduction were significantly influenced (P<0.001) by femoral torsion disorder conditions. Medial femoral torsion increased tibial adduction and decreased internal rotation during knee flexion. Opposite changes were observed during lateral femoral torsion. Concerning translations, medial femoral torsion induced a significant (P<0.05) decrease of medial translation and inversely for lateral femoral torsion. No interactions between femoral torsion disorders and range of motion were observed. INTERPRETATION: Our results showed that medial and lateral femoral torsion disorders induced alterations of femoro-tibial kinematics when applied in normally aligned lower limbs. These results highlight a potential clinical relevance of the effect of femoral torsion alterations on knee kinematics that may be related to the development of long-term knee disease.

Tolerance of upper extremity pneumatic tourniquets and their effect on grip strength.

This study was undertaken to evaluate tourniquet tolerance in healthy people. An arm tourniquet was inflated to 100 mmHg above systolic blood pressure for 21 minutes. We measured pain and grip strength before, during and at various times after deflation. We tested 40 subjects (20 women and 20 men) with an average age of 38 (range 22-58) years. Eight individuals did not tolerate the tourniquet for this length of time and the test was stopped. Visual analogical scale had a globally linear increase during tourniquet application. We noted a sensation of well-being just after deflation, quickly replaced by pain in the tested limb due to limb reperfusion. We also noted a significant loss of strength in the tested limb, which completely recovered by 48 hours. We also observed a significant loss of strength in the contralateral hand, which also recovered by 48 hours. The possible reasons for these temporary losses of strength in both the ipsilateral and contralateral limbs are discussed.

Global 3D head-trunk kinematics during cervical spine manipulation at different levels.

OBJECTIVE: Determination of the three-dimensional kinematics of the head relative to the upper trunk obtained during a manipulation applied on two different cervical levels and on both sides. DESIGN: Descriptive study performed on 14 asymptomatic volunteers. The range of motion was measured by a 3D electrogoniometer during manipulation executed by the same practitioner. BACKGROUND: Spinal manipulative therapy is a common treatment approach in patients suffering from some spinal disorders. Complications exist; they are thought to be related to the force applied by the practitioner and the range of spinal motion obtained during the manipulation. Yet, little is known about cervical spine motion during manipulation. METHODS: Three dimensional electrogoniometry using a 6 degree-of-freedom spatial linkage fixed between the head and the upper trunk was used to record the pattern of motion and the amplitudes obtained during a manipulation on two cervical levels (C3 and C5) and on left and right sides. On single practitioner applied the same technique to all subjects in a seated position. RESULTS: The side and the spinal level manipulated did not influence 3D ranges of motion. The mean ranges of motion obtained were 30 degrees axial rotation, 46 degrees lateral bending and 2 degrees flexion. A significant difference of the flexion-extension range existed between manipulations with and without audible release. Axial rotation and lateral bending ranges were correlated. Except for lateral bending which was close to active range, the motion ranges obtained during manipulation were well below active range of motion reported in literature. CONCLUSIONS: The results of this study suggest that for the kind of manipulation applied, maximal amplitude between head and trunk does not exceed physiological active range of motion. The amplitude for rotation, which is generally assumed to involve greatest risks for negative side effects, is significantly lower than during active motion. As the study was performed with one practitioner, this result may only be generalized with care. RELEVANCE: In spinal manipulative therapy, extreme range of motion as the result of the forces applied is generally believed to represent a major risk for negative side effects, especially with regard to the cervical spine. With a multiple component technique, amplitudes between head and upper trunk were shown not to differ significantly with regard to the side nor to the spinal level. Recorded ranges of motion did not exceed those reported for active motion in literature.