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Biomedical subjects

Martin C Normand

Publications and source records attributed to Martin C Normand.

9 recordsLinked to original sources

Postural development in school children: a cross-sectional study.

BACKGROUND: Little information on quantitative sagittal plane postural alignment and evolution in children exists. The objectives of this study are to document the evolution of upright, static, sagittal posture in children and to identify possible critical phases of postural evolution (maturation). METHODS: A total of 1084 children (aged 4-12 years) received a sagittal postural evaluation with the Biotonix postural analysis system. Data were retrieved from the Biotonix internet database. Children were stratified and analyzed by years of age with n = 36 in the youngest age group (4 years) and n = 184 in the oldest age group (12 years). Children were analyzed in the neutral upright posture. Variables measured were sagittal translation distances in millimeters of: the knee relative to the tarsal joint, pelvis relative to the tarsal joint, shoulder relative to the tarsal joint, and head relative to the tarsal joint. A two-way factorial ANOVA was used to test for age and gender effects on posture, while polynomial trend analyses were used to test for increased postural displacements with years of age. RESULTS: Two-way ANOVA yielded a significant main effect of age for all 4 sagittal postural variables and gender for all variables except head translation. No age x gender interaction was found. Polynomial trend analyses showed a significant linear association between child age and all four postural variables: anterior head translation (p < 0.001), anterior shoulder translation (p < 0.001), anterior pelvic translation (p < 0.001), anterior knee translation (p < 0.001). Between the ages of 11 and 12 years, for anterior knee translation, T-test post hoc analysis revealed only one significant rough break in the continuity of the age related trend. CONCLUSION: A significant linear trend for increasing sagittal plane postural translations of the head, thorax, pelvis, and knee was found as children age from 4 years to 12 years. These postural translations provide preliminary normative data for the alignment of a child's sagittal plane posture.

Journal Article↗

Validation of a computer analysis to determine 3-D rotations and translations of the rib cage in upright posture from three 2-D digital images.

Since thoracic cage posture affects lumbar spine coupling and loads on the spinal tissues and extremities, a scientific analysis of upright posture is needed. Common posture analyzers measure human posture as displacements from a plumb line, while the PosturePrint claims to measure head, rib cage, and pelvic postures as rotations and translations. In this study, it was decided to evaluate the validity of the PosturePrint Internet computer system's analysis of thoracic cage postures. In a university biomechanics laboratory, photographs of a mannequin thoracic cage were obtained in different postures on a stand in front of a digital camera. For each mannequin posture, three photographs were obtained (left lateral, right lateral, and AP). The mannequin thoracic cage was placed in 68 different single and combined postures (requiring 204 photographs) in five degrees of freedom: lateral translation (Tx), lateral flexion (Rz), axial rotation (Ry), flexion-extension (Rx), and anterior-posterior translation (Tz). The PosturePrint system requires 13 reflective markers to be placed on the subject (mannequin) during photography and 16 additional "click-on" markers via computer mouse before a set of three photographs is analyzed by the PosturePrint computer system over the Internet. Errors were the differences between the positioned mannequin and the calculated positions from the computer system. Average absolute value errors were obtained by comparing the exact inputted posture to the PosturePrint computed values. Mean and standard deviation of computational errors for sagittal displacements of the thoracic cage were Rx=0.3+/-0.1 degrees , Tz=1.6+/-0.7 mm, and for frontal view displacements were Ry=1.2+/-1.0 degrees , Rz=0.6+/-0.4 degrees , and Tx=1.5+/-0.6 mm. The PosturePrint system is sufficiently accurate in measuring thoracic cage postures in five degrees of freedom on a mannequin indicating the need for a further study on human subjects.

Biomechanical Phenomena↗

Learning spinal manipulation: the importance of augmented feedback relating to various kinetic parameters.

BACKGROUND CONTEXT: Spinal manipulation is a widely accepted therapeutic approach in the treatment of back pain. In standard training programs, feedback on student performances is provided by an instructor based on teaching and clinical experience. Systematic study of the type of augmented feedback provided and skill learning is lacking in the literature. PURPOSE: The goal of this investigation is to compare the performance of two groups of chiropractic students, one receiving traditional training from experienced instructors, and the other, augmented feedback on specific biomechanical aspects of spinal manipulation therapy using an instrumented manikin. STUDY DESIGN: Randomized controlled study. PATIENT SAMPLE: Thirty-one fourth-year students from the Department of Chiropractic of Université du Québec à Trois-Rivières participated in this study. OUTCOME MEASURES: Kinetic parameters (force-time curves) of spinal manipulation were evaluated. METHODS: Spinal manipulation parameters were measured before and after a 5-week training period in which one group received standard chiropractic training while a second group received augmented feedback about specific biomechanical parameters of spinal manipulation. For both groups, practice scheduling and time duration were similar and consisted of a weekly practice session of 90 minutes for five consecutive weeks. Both groups had to practice thoracic spine manipulation throughout the training period. RESULTS: Both groups showed a decrease in peak force applied, with a diminution in the number of trials where a downward incisural point was present in preload force. Participants in the feedback training group significantly reduced their peak force variability and significantly increased their preload force. No significant difference was observed for time to peak force. CONCLUSIONS: The results of this study highlight the merits of practicing with an instrumented manikin or other instrumented training aids. Such a device can provide specific feedback on specific parameters of the task during learning; it can also serve as a tool to assess the progress of students and eliminate the risks relating to repetitive spinal manipulative therapy practice on student colleagues.

Adult↗

Measurement of the pressure applied during motion palpation and reliability for cervical spine rotation.

OBJECTIVE: To measure the pressure applied during motion palpation for cervical spine rotation and to verify its effect on reliability when the kinematics of the test are standardized. METHODS: The pressure of palpation used during the test of cervical spine rotation was measured by means of flexible and extra-fine pressure sensors linked to an electronic interface. Seven pressure measurements (left rotation from C1 to C7) for each of 24 examiners were taken. In addition, the examiners were asked to detect the presence of intervertebral fixation while palpating. RESULTS: Pressure of palpation varied from 4.0 to 41.0 N/cm2 among the examiners. Standardization of the kinematics of the test establishes a strong reliability of identifying a fixation (kappa varying from 0.701 to 0.748). CONCLUSIONS: The pressure applied during motion palpation for cervical spine rotation is light to moderate. It can vary tenfold (4-41 N/cm2) and remain reliable for identifying a fixation as long as the kinematics of the test are standardized.

Adult↗

Reliability and measurement error of the BioTonix video posture evaluation system--Part I: Inanimate objects.

OBJECTIVE: To investigate the reliability, concurrent validity, and error of a new video digitizing system for evaluating posture when applied to inanimate objects. DESIGN: Delayed repeated measures of digital images of inanimate objects. SETTING: University laboratory. METHODS: Digital video images of inanimate objects (5 parallelograms) of different sizes and shapes were obtained with the BioTonix postural evaluation system. Three examiners digitized video images of inanimate objects twice; the second data collection was 1 week after the first set. The objects were digitized with both high- and low-resolution settings of the video screen. The Tonix's measurements were statistically compared with the actual object dimensions. Statistical evaluations of reliability and validity were conducted. RESULTS: For distances, both intraclass and interclass correlation coefficients were very high, 0.99 for the estimate. The low- versus high-resolution settings were comparable for distances. For angles, on the low-resolution setting, both intraclass and interclass correlation coefficients were very high: 0.969 and 0.953. On the high-resolution setting, for angles, both intraclass and interclass coefficients were well above 0.99. The difference of the actual size and the means of the digitized measurements of the means were small: at most 1.5 degrees for angles and 3.3 mm for distances. The standard deviations were small, and the confidence intervals were narrow. CONCLUSIONS: Our results demonstrate that the BioTonix's video system has high degrees of reliability and validity. Thus this system would seem suitable for clinical use in the analysis of posture.

Biomedical Technology↗

The kinematics of motion palpation and its effect on the reliability for cervical spine rotation.

BACKGROUND: The reliability of a test depends on its standardization. Instrumental measurement of the reproducibility of the test is an effective way to evaluate the level of standardization obtained. Improved standardization is believed to yield greater reliability. OBJECTIVE: The objectives of this study were to measure the technical ability of an examiner to reproduce the kinematics of motion palpation for cervical spine rotation and to evaluate the effect of standardization on the reliability of the test. DESIGN: A study of reproducibility of the kinematics of the test for cervical spine rotation was conducted by means of a computerized system of analysis of movement. The reliability when reproducibility was achieved was compared with reliability when it failed. RESULTS: The data collected enable us to establish a standardized protocol for the execution of the test. The standardized palpation is executed within 6 of inclination from the pure plane of rotation. The successful reproduction of the kinematics of the test raises its reliability to detect the presence of fixations (kappa raising from 0.337 and 0.352 to 0.682). CONCLUSIONS: A greater reliability, arising from a high level of reproducibility, enables us to document the advantages of the standardization of motion palpation in chiropractic.

Adult↗

Evaluation of a specific home exercise program for low back pain.

BACKGROUND: The prescription of exercise as a conservative treatment for lumbar pain is frequent and seems effective for the chronic cases of nonspecific low back pain. However, there is no evidence favoring one type of exercise over another. Often, exercise programs are prescribed without adequate evaluation of the individual characteristics like posture, muscular force, and extensibility. Patients with totally different causes of low back pain will often be given the same type of exercises. OBJECTIVE: Our objective was to compare the effectiveness of 2 home exercise programs in decreasing disability and pain related to subacute and chronic nonspecific low back pain. To do so we compared a specific (individualized) exercise program with a program of commonly prescribed exercises for low back pain. METHOD: In a control group study, 20 patients with chronic or subacute nonspecific low back pain participated after giving their informed consent. All subjects were evaluated (physical evaluation of lumbar and pelvic muscles [1] force and [2] extensibility, [3] trunk range of motion) and then divided in 2 groups: 10 patients received specific exercises (experimental group) based on their evaluation, and 10 patients received a commonly prescribed exercise program for low back pain (control group). Six weeks later a second physical evaluation was conducted. Pain (visual analog pain scale) and disability (modified Oswestry) questionnaires were also completed by each subject at both evaluations. DESIGN: This was a randomized experimental study. RESULTS: Both groups had similar age, weight, and sex characteristics. The experimental group showed significant improvements for some components targeted by the program. The control group significantly had improvement of some physical characteristics not related to their initial deficits. Even if both groups showed some improvements in muscular force and extensibility, only the members of the group who received specific exercises significantly reduced their level of pain and disability. Both groups showed a similar rate of participation in the program. CONCLUSION: The results of this study suggest that applying a specific physical evaluation and exercise prescription is an appropriate treatment for people having subacute or chronic nonspecific pain. Thus clinicians should prescribe exercise programs based on individual muscular deficits rather than most commonly prescribed exercise programs.

Activities of Daily Living↗

Comparison of mechanical force of manually assisted chiropractic adjusting instruments.

OBJECTIVE: To quantify the force-time and force-delivery characteristics of six commonly used handheld chiropractic adjusting devices. METHODS: Four spring-loaded instruments, the Activator Adjusting Instrument; Activator II Adjusting Instrument, Activator III Adjusting Instrument, and Activator IV Adjusting Instrument, and two electromechanical devices, the Harrison Handheld Adjusting Instrument and Neuromechanical Impulse Adjusting Instrument, were applied to a dynamic load cell. A total of 10 force-time histories were obtained at each of three force excursion settings (minimum to maximum) for each of the six adjusting instruments at preload of approximately 20 N. RESULTS: The minimum-to-maximum force excursion settings for the spring-loaded mechanical adjusting instruments produced similar minimum-to-maximum peak forces that were not appreciably different for most excursion settings. The electromechanical adjusting instruments produced short duration ( approximately 2-4 ms), with more linear minimum-to-maximum peak forces. The force-time profile of the electromechanical devices resulted in a more uniform and greater energy dynamic frequency response in comparison to the spring-loaded mechanical adjusting instruments. CONCLUSIONS: The handheld, electromechanical instruments produced substantially larger peak forces and ranges of forces in comparison to the handheld, spring-loaded mechanical devices. The electromechanical instruments produced greater dynamic frequency area ratios than their mechanical counterparts. Knowledge of the force-time history and force-frequency response characteristics of spinal manipulative instruments may provide basic benchmarks and may assist in understanding mechanical responses in the clinical setting.

Benchmarking↗

Diagnosis and management of posttraumatic piriformis syndrome: a case study.

OBJECTIVE: The aim of this study is to describe the clinical management of a young male patient with sciatica symptoms that developed after an avulsion of the ischial tuberosity. This is a rare injury, but complications may occur. CLINICAL FEATURE: A 19-year-old patient developed sciatica 6 months after a football injury. The patient described his symptoms as a shooting pain from the buttock to the lateral part of the foot, along the back of his thigh and calf, sometimes accompanied by paresthesia. Physical examination showed restricted hip range of motion and a positive Bonnet's test. X-ray analysis revealed a bony overgrowth of the right ischial tuberosity. INTERVENTION AND OUTCOME: A treatment plan was designed to decrease the pain level, increase sacroiliac and lumbar joint mobility, and augment muscular extensibility. The patient received 20 treatments over a period of approximately 3 months. Complete recovery was observed 5 months later. CONCLUSION: Although many differential diagnoses were contemplated, it is most likely that changes in muscular tension and gait pattern, resulting from the ischial tuberosity avulsion, contributed to overuse of the piriformis muscle leading to a piriformis syndrome.

Adult↗