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1.
Eur Spine J ; 26(9): 2467-2474, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28776132

RESUMEN

PURPOSE: This paper evaluates the long-term impact of a Canadian mass media campaign on general public beliefs about staying active when experiencing low back pain (LBP). METHODS: Changes in beliefs about staying active during an episode of LBP were studied using telephone and web-based surveys. Logistic regression analysis was used to investigate changes in beliefs over time and the effect of exposure to campaign messaging. RESULTS: The percentage of survey respondents agreeing that they should stay active through LBP increased annually from 58.9 to ~72.0%. Respondents reporting exposure to campaign messaging were statistically significantly more likely to agree with staying active than respondents who did not report exposure to campaign messaging (adjusted OR, 95% CI = 1.96, 1.73-2.21). CONCLUSION: The mass media campaign had continued impact on public LBP beliefs over the course of 7 years. Improvements over time were associated with exposure to campaign messaging.


Asunto(s)
Educación en Salud/métodos , Conocimientos, Actitudes y Práctica en Salud , Dolor de la Región Lumbar/psicología , Dolor de la Región Lumbar/rehabilitación , Medios de Comunicación de Masas , Adolescente , Adulto , Anciano , Canadá , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Programas y Proyectos de Salud , Encuestas y Cuestionarios , Adulto Joven
2.
Can Fam Physician ; 62(3): e129-37, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27427564

RESUMEN

OBJECTIVE: To evaluate an a priori threshold for advanced imaging in patients with spinal pain. DESIGN: Patients with spinal pain in any region for 6 to 52 weeks were assessed to determine if radiologic studies beyond x-ray scans were indicated, including magnetic resonance imaging (MRI), computed tomography (CT), and radionuclide bone scans. An a priori threshold was set before MRI, CT, or bone scans would be considered. Those who did not have MRI, CT, or bone scans ordered were followed for at least 1 year to determine if any of them went on to be diagnosed with a more serious spinal disorder (eg, infection, fracture, spondylitis, tumour, neurologic compression). SETTING: Four large primary care clinics in Edmonton, Alta. PARTICIPANTS: A total of 1003 consecutively presenting patients with symptoms suspected to be related to the spine (for a duration of generally 6 to 52 weeks) who had not already undergone advanced imaging and did not have a diagnosis of nonbenign back pain. MAIN OUTCOME MEASURES: Number of cases of nonbenign spinal disorder in participants who underwent advanced imaging and participants who did not undergo advanced imaging (ie, did not have any red flags). RESULTS: There were 399 women (39.8%) and 604 men (60.2%). The mean (SD) age of the group was 47.2 (14.6) years. The mean (SD) duration of symptoms was 15.1 (8.6) weeks. Of the 1003 participants, 110 met an a priori threshold for undergoing at least 1 of MRI, CT, or bone scan. In these 110 participants, there were newly diagnosed cases of radiculopathy (n = 12), including a case of cauda equina syndrome; spondyloarthropathy (n = 6); occult fracture (n = 2); solitary metastasis (n = 1); epidural lipomatosis (n = 1); osteomyelitis (n = 1), and retroperitoneal hematoma (n = 1), each of which was considered likely to be the cause of the patient's spinal symptoms. The remaining 893 participants were followed for at least 1 year and none showed evidence of a nonbenign cause of his or her spinal pain. CONCLUSION: In the evaluation of nonspecific spinal pain and symptoms, setting and following an a priori threshold for ordering MRI, CT, or bone scans in the spirit of the current Choosing Wisely Canada recommendations has a very low risk of missing a case of a serious cause of back pain.


Asunto(s)
Dolor de Espalda/diagnóstico , Diagnóstico por Imagen/estadística & datos numéricos , Enfermedades de la Columna Vertebral/diagnóstico , Procedimientos Innecesarios/economía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Alberta , Diagnóstico por Imagen/economía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Auditoría Médica , Persona de Mediana Edad , Guías de Práctica Clínica como Asunto , Adulto Joven
3.
Rheumatol Int ; 35(1): 55-9, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24985364

RESUMEN

UNLABELLED: The aim of the study was to examine the effect of a daily pain diary on recovery from acute low back sprain. SUMMARY OF BACKGROUND DATA: Pain diaries are often recommended to or used by patients suffering with acute lumbar (low back) sprain. Diaries have been shown to be associated, however, with a slower rate of recovery after whiplash (neck) injury. The effect of diary use on recovery from low back injury is unknown. Subjects with acute lumbar (low back) sprain were randomly assigned to one of the two groups: a diary group and control group. A total of 58 out of 62 initially recruited subjects were seen in follow-up 3-month post-injury, 29 in the diary group, and 29 in the control group. Data were gathered within 1 week of injury on sex, age, and Oswestry Disability Questionnaire (ODQ) scores. The diary group was asked then to keep a record of their overall pain experience, rating their pain on a scale of 1-10 on a daily basis for 4 weeks. At the outset, both groups had similar mean age, sex distribution, and mean ODQ scores. After 4 weeks of pain diary use, fewer diary group subjects reported recovery at 3 months compared with the control group (52 vs. 79 %, respectively, p < 0.05). The use of a pain diary for 4 weeks in acute lumbar sprain subjects is associated with a reduced rate of recovery.


Asunto(s)
Dolor de la Región Lumbar/diagnóstico , Registros Médicos , Recuperación de la Función/fisiología , Esguinces y Distensiones/diagnóstico , Adulto , Evaluación de la Discapacidad , Femenino , Humanos , Dolor de la Región Lumbar/fisiopatología , Dolor de la Región Lumbar/psicología , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Índice de Severidad de la Enfermedad , Esguinces y Distensiones/fisiopatología , Esguinces y Distensiones/psicología , Encuestas y Cuestionarios , Adulto Joven
4.
Aust Fam Physician ; 43(8): 559-62, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25114995

RESUMEN

BACKGROUND: The effect of expectation of recovery on the recovery rate of whiplash patients in the primary care setting is not known. METHODS: Whiplash patients were assessed in a primary care setting within 1 week of their collision for their expectations of recovery and were re-examined 3 months later for recovery. RESULTS: Initial expectations of recovery predicted recovery. According to adjusted odds ratios, subjects who expected 'to get better slowly' had a recovery rate that was nearly 1.9 times that of subjects with poor recovery expectations. Subjects who expected 'to get better soon' had a recovery rate that was 2.6 times greater than either of those with poor recovery expectations. DISCUSSION: In the primary care setting, asking patients with whiplash about their expectations of recovery is a useful predictor of their outcome.


Asunto(s)
Atención Primaria de Salud , Lesiones por Latigazo Cervical/psicología , Adolescente , Adulto , Anciano , Actitud Frente a la Salud , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dolor de Cuello/etiología , Percepción , Pronóstico , Recuperación de la Función , Factores de Tiempo , Lesiones por Latigazo Cervical/complicaciones , Lesiones por Latigazo Cervical/fisiopatología , Adulto Joven
5.
J Manipulative Physiol Ther ; 36(6): 359-63, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23830710

RESUMEN

OBJECTIVE: The objective of this study was to compare the effect of customized foot orthotics in addition to usual care (UC) compared with UC alone for the treatment of patients with chronic low back pain after work-related injury. METHODS: Sixty-two consecutive patients presenting with chronic (>3 months), nonspecific, low back pain following work-related low back injury were included in the study. A total of 30 patients in the UC group were given a 6-week exercise therapy program along with prescription analgesics. The intervention group, composed of 32 patients, received UC in addition to customized foot orthotics (orthotics group). All subjects completed the Oswestry Disability Index at the initiation of the study and at 8-week follow-up. Work disability, as defined by working at usual, preinjury job labor level, was recorded at baseline and 8-week follow-up. RESULTS: A total of 28 subjects in the UC group and 32 in the orthotics group completed the study. The 2 groups were well matched in terms of age, sex distribution, and duration of low back pain as well as baseline Oswestry Disability Index score. At 8 weeks, both groups had improved. The orthotics group had a lower Oswestry Disability Index than the UC group (P < .01), with a smaller proportion of the orthotics group using any form of prescribed analgesics for back pain (P < .05). CONCLUSIONS: The findings showed that patients in this study with chronic, nonspecific low back pain following work-related low back injury had greater improvement in short-term outcomes with orthotics and UC than with UC alone.


Asunto(s)
Traumatismos de la Espalda/terapia , Dolor Crónico/terapia , Ortesis del Pié , Enfermedades Profesionales/terapia , Traumatismos Ocupacionales/terapia , Adulto , Traumatismos de la Espalda/complicaciones , Femenino , Humanos , Dolor de la Región Lumbar/etiología , Dolor de la Región Lumbar/terapia , Masculino , Persona de Mediana Edad , Enfermedades Profesionales/etiología , Traumatismos Ocupacionales/complicaciones , Adulto Joven
7.
Aust Fam Physician ; 39(11): 863-6, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21301661

RESUMEN

BACKGROUND: Central sensitisation is associated with chronic pain in whiplash patients. Predicting which patients will develop central sensitisation is difficult but patient expectations of recovery predict a variety of outcomes in whiplash patients. METHOD: Ninety-one whiplash patients were assessed within 1 week of their collision in order to ascertain their expectations of recovery and were then re-examined 3 months later with the Brachial Plexus Provocation Test (BPPT) as a sign of central sensitisation. RESULTS: Adjusting for a number of predictors, patient expectation of recovery was found to predict the results of the BPPT. Subjects who expected 'to get better soon' had a BPPT angle that was 42 degrees less (ie. closer to normal or full range) than any of the subjects who had poor recovery expectations. DISCUSSION: Whiplash patients who expect 'never to get better' or 'don't know' have a much higher likelihood of developing at least one sign of central sensitisation 3 months after their collision.


Asunto(s)
Plexo Braquial/lesiones , Hiperalgesia/etiología , Dolor/etiología , Lesiones por Latigazo Cervical/complicaciones , Adolescente , Adulto , Anciano , Análisis de Varianza , Plexo Braquial/patología , Estudios de Cohortes , Evaluación de la Discapacidad , Femenino , Indicadores de Salud , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Pronóstico , Medición de Riesgo , Factores de Riesgo , Encuestas y Cuestionarios , Resultado del Tratamiento , Lesiones por Latigazo Cervical/rehabilitación , Adulto Joven
9.
J Am Dent Assoc ; 138(1): 86-93, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17197407

RESUMEN

BACKGROUND: The authors report the incidence of and factors associated with reduced and/or painful jaw movement after motor vehicle collisions that resulted in whiplash-associated disorders (WADs). METHODS: All adults filing collision-related personal injury claims during an 18-month period in Saskatchewan, Canada, were evaluated via questionnaire to determine demographic characteristics, precollision health (including jaw pain), collision parameters and collision-related symptoms, including reduced and/or painful jaw movement and injury-related neck pain. The authors excluded patients who were hospitalized for more than two days and those who sustained injuries as a pedestrian, bicyclist or motorcyclist. In determining incidence rates, the authors also excluded those who had had jaw pain before the collision. RESULTS: The incidence of reduced and/or painful jaw movement was 14.9 percent (n = 1,158), and it was higher in subjects with WADs (15.8 percent) than in those without WADs (4.7 percent; relative risk = 3.36, 95 percent confidence interval, 2.36 to 4.78). Within the WAD injuries, multivariable logistic regression revealed that the onset of reduced and/or painful jaw movement was associated with female sex; age < 50 years; having hit one's head in the collision; and postinjury symptoms of difficulty swallowing, ringing in the ears, dizziness or unsteadiness, and more intense neck pain. Collision parameters, such as head position at the time of the crash and headrest use and type, were not associated with onset of jaw symptoms. CONCLUSIONS: Reduced or painful jaw movement was more common in people with WADs than in those with other collision-related injuries. Among those with WADs, reduced or painful jaw movement was more common in women and younger people. CLINICAL IMPLICATIONS: Reduced or painful jaw movement is an important aspect of WADs, and more studies are needed to determine how to best assess and treat this problem.


Asunto(s)
Accidentes de Tránsito , Trastornos de la Articulación Temporomandibular/etiología , Lesiones por Latigazo Cervical/complicaciones , Accidentes de Tránsito/clasificación , Adolescente , Adulto , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Traumatismos Cerrados de la Cabeza/complicaciones , Estado de Salud , Humanos , Hipoestesia/etiología , Masculino , Persona de Mediana Edad , Dolor de Cuello/etiología , Dimensión del Dolor , Vigilancia de la Población , Recuperación de la Función/fisiología , Factores Sexuales , Dolor de Hombro/etiología , Inconsciencia/complicaciones
10.
J Manipulative Physiol Ther ; 30(6): 456-8, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17693336

RESUMEN

PURPOSE: This study reports the responsiveness of the Short-Form 36 (SF-36) and Oswestry Disability Questionnaire (ODQ) to treatment with customized foot orthotics. METHODS: Thirty consecutive patients presenting to a primary care clinic with chronic (>3 months), nonspecific, low back pain and/or soft tissue lower limb disorders completed the SF-36 and ODQ before and 6 weeks after prescription of customized foot orthotics. Locations of any pain in the lower half of the body (including the low back), age, sex, and duration of the most chronic pain were recorded. Responsiveness statistics of the ODQ and SF-36 physical and mental summary scores were calculated, as was correlation among these scores and the self-reported pain improvement scores. RESULTS: All subjects completed the baseline and 6-week questionnaires. The mean age of the sample was 53.9 +/- 12.9 years, with 57% men and 43% women. The mean duration of the most chronic pain symptom was 14 +/- 14 months (range, 3-60 months). The mean ODQ score at baseline was 42.8% +/- 14. 8% and at 6 weeks was 16.6% +/- 5.0%. The physical component score of the SF-36 was 39.8 +/- 5.0 at baseline and at 6 weeks was 47.3 +/- 3.8. The mental component score of the SF-36 at baseline was 45.7 +/- 6.1 and at 6 weeks was 47.9 +/- 5.0. The responsiveness of the ODQ was calculated to be 9.40, the responsiveness being 1.77 for the physical component score of the SF-36 and 0.24 for the mental component score of the SF-36. CONCLUSIONS: In this cohort, the ODQ and the physical component of the SF-36 appear to be responsive to treatment effects, with the ODQ having the highest responsiveness. The ODQ may be a useful outcome measure in trials of the effectiveness of customized foot orthotics in patients with nonspecific, chronic low back and/or soft tissue lower limb pain.


Asunto(s)
Evaluación de la Discapacidad , Pie , Indicadores de Salud , Pierna , Dolor de la Región Lumbar/terapia , Aparatos Ortopédicos , Manejo del Dolor , Encuestas y Cuestionarios , Adulto , Enfermedad Crónica , Femenino , Humanos , Dolor de la Región Lumbar/complicaciones , Dolor de la Región Lumbar/fisiopatología , Dolor de la Región Lumbar/psicología , Masculino , Salud Mental , Persona de Mediana Edad , Dolor/complicaciones , Dolor/psicología , Encuestas y Cuestionarios/normas , Resultado del Tratamiento
12.
J Neuroeng Rehabil ; 3: 10, 2006 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-16704734

RESUMEN

BACKGROUND: The cervical muscles are considered a potential site of whiplash injury, and there is a need to understand the cervical muscle response under non-conventional whiplash impact scenarios, including variable body position and impact direction. There is no data, however, on the effect of occupant position on the muscle response to frontal impacts. Therefore, the objective of the study was to measure cervical muscle response to graded right anterolateral impacts. METHODS: Twenty volunteers were subjected to right anterolateral impacts of 4.3, 7.8, 10.6, and 12.8 m/s(2) acceleration with their trunk flexed forward 45 degrees and laterally flexed right or left by 45 degrees. Bilateral EMG of the sternocleidomastoids, trapezii, and splenii capitis and acceleration of the sled, torso, and head were measured. RESULTS AND DISCUSSION: With either direction of trunk flexion at impact, the trapezius EMGs increased with increasing acceleration (p < 0.05). Time to onset of the electromyogram and time to peak electromyogram for most muscles showed a trend towards decreasing with increasing acceleration. With trunk flexion to the left, the left trapezius generated 38% of its maximal voluntary contraction (MVC) EMG, while the right trapezius generated 28% of its MVC EMG. All other muscles generated 25% or less of this measure (25% for the left splenius capitis, 8% for the right splenius capitis, 6% for the left sternocleidomastoid, and 2% for the left sterncleidomastoid). Conversely, with the trunk flexed to the right, the right trapezius generated 44% of its MVC EMG, while the left trapezius generated 31% of this value, and all other muscles generated 20% or less of their MVC EMG (20% for the left splenius capitis, 14% for the right splenius capitis, 4% for both the left and right sternocleidomastoids). CONCLUSION: When the subject sits with trunk flexed out of neutral posture at the time of anterolateral impact, the cervical muscle response is dramatically reduced compared to frontal impacts with the trunk in neutral posture. In the absence of bodily impact, the flexed trunk posture appears to produce a biomechanical response that would decrease the likelihood of cervical muscle injury in low velocity impacts.

13.
J Manipulative Physiol Ther ; 29(2): 115-25, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16461170

RESUMEN

OBJECTIVE: The objective of this study was to determine the effect of a standard 3-point lap-and-shoulder seat belt and car seat on the electromyogram (EMG) response of the cervical muscles to increasing low-velocity impacts in comparison with that of a rigid seat and 5-point restraint. METHODS: Seventeen healthy volunteers were subjected to rear, frontal, right and left lateral and bilateral anterolateral, and posterolateral impacts with an acceleration varying from 4.4 to 16.8 m/s(2) while in a car seat with lap-and-shoulder seat belt. RESULTS: For rear-end impacts, whether straight on, right posterolateral, or left posterolateral, all muscles generated 50% or less of the maximal voluntary contraction (MVC) EMG. In straight-on rear impacts, the sternocleidomastoid was symmetrically the most active; however, in posterolateral impacts, the sternocleidomastoid contralateral to impact direction was more active than its counterpart. For a right lateral impact, at the highest acceleration, the left splenius capitis generated 47% of its MVC and the left trapezius did 46% of its MVC. In a left lateral impact, the right splenius capitis generated 48% of its MVC and the right trapezius did 57% of its MVC. In a straight-on frontal impact, the left trapezius generated 35% of its MVC and the right trapezius did 48% of its MVC. In a left anterolateral impact, the right splenius generated 60% of its MVC and the right trapezius did 66% of its MVC. Similarly, in a right anterolateral impact, the contralateral splenius muscle increased its activity to 52% of its MVC and the left trapezius was at 52% of its MVC. CONCLUSIONS: Compared with previously reported impact studies with a rigid seat and 5-point harness, the use of a 3-point lap-and-shoulder seat belt with a standard car seat did not appear to adversely affect cervical muscle response. In very-low-velocity and low-velocity impact experiments, seat belt and seat type may not significantly alter cervical EMG and kinematics.


Asunto(s)
Electromiografía , Músculos del Cuello/fisiopatología , Cinturones de Seguridad , Lesiones por Latigazo Cervical/fisiopatología , Aceleración , Adulto , Diseño de Equipo , Cabeza/fisiopatología , Humanos , Contracción Muscular , Valores de Referencia , Factores de Tiempo , Lesiones por Latigazo Cervical/diagnóstico
14.
Aust Fam Physician ; 35(5): 367-8, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16680223

RESUMEN

BACKGROUND: Excess cerumen (earwax) in the external auditory canal is associated with symptoms of earache, fullness in the ears, and diminished hearing. These symptoms, and tinnitus, are commonly associated with whiplash injury. METHODS: Eighty-six whiplash patients were examined to determine if there was a correlation between symptoms of earache, fullness in the ear, diminished hearing, and tinnitus, and the degree of cerumen occlusion. Cerumen occlusion was measured by visualisation of the tympanic membrane and graded according to a 4 point scale. RESULTS: Of 71 subjects reporting no acute onset (within 7 days of the collision that caused their whiplash) earache, fullness in the ears, hearing loss, or tinnitus, 62 had little or no cerenum occlusion. Of seven subjects reporting tinnitus but no other auditory symptoms, none had greater than moderate cerenum occlusion. Of eight subjects reporting one or more of acute onset earache, fullness in the ears, diminished hearing, and tinnitus, seven had complete cerenum occlusion in the affected ear. DISCUSSION: The findings suggest high grade cerumen occlusion frequently occurs in the ear affected by acute auditory symptoms. However, tinnitus alone has no apparent association with cerumen occlusion. It is possible that a significant number of acute onset auditory symptoms reported in whiplash patients have a benign cause.


Asunto(s)
Cerumen , Enfermedades del Oído/epidemiología , Lesiones por Latigazo Cervical/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Alberta/epidemiología , Causalidad , Comorbilidad , Conducto Auditivo Externo , Enfermedades del Oído/clasificación , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad
15.
Aust Fam Physician ; 35(8): 653-4, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16894446

RESUMEN

BACKGROUND: General practitioners often need to track outcomes of whiplash patients, and a disability questionnaire may be useful. METHODS: Whiplash patients who attended primary care clinics in Edmonton, Canada were interviewed 3 months postcollision. Subjects were asked a global recovery question: "Do you feel you have recovered fully from your accident injuries?" Subjects then completed the Whiplash Disability Questionnaire (WDQ). RESULTS: A total of 131 subjects participated. Of these, 52 (39.7%) reported that they felt they had recovered. Those who reported complete recovery had a mean WDQ score of 2.5 and those who reported they had not recovered had a mean WDQ score of 29.9. All who responded "yes" to the recovery question had a WDQ score below 13, while all those responding "no" to the recovery question had a WDQ score of 13 or more. DISCUSSION: The WDQ as an outcome measure may be useful in clinical practice.


Asunto(s)
Evaluación de la Discapacidad , Medicina Familiar y Comunitaria , Atención Primaria de Salud , Resultado del Tratamiento , Lesiones por Latigazo Cervical/rehabilitación , Adolescente , Adulto , Anciano , Alberta , Femenino , Encuestas Epidemiológicas , Humanos , Seguro de Salud , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Lesiones por Latigazo Cervical/fisiopatología
16.
Eur J Rheumatol ; 3(4): 175-178, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28149662

RESUMEN

Practice audits are useful opportunities to improve practice efficiency and effectiveness, reduce clinical errors, demonstrate quality care to stakeholders, promote high standards of practice, lower the risk of liability, and foster practice change. However, a benefit that is usually overlooked is the possibility of publication of the results of a practice audit. Publication (research) has a number of benefits for the clinician, including skill development as a scholar, communicator, professional, and collaborator. A practice audit is beneficial to an individual physician; furthermore, publication of the audit results could be beneficial for many others such as health care providers, patients, and other stakeholders in a health care system. The problem is that practice audits often begin without a clear plan. The important steps in planning and carrying out a practice audit can be captured by thinking about how a research publication evolves. Thus, a good researcher is a good practice auditor. This paper reviews the author's experience and provides examples and directions of the process of practice-audit-publish.

17.
J Orthop Res ; 23(1): 224-30, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15607897

RESUMEN

OBJECTIVE: To determine the response of the cervical muscles to whiplash-type perturbations through low-velocity frontal impacts when the head is rotated to the right and left. METHODS: Twenty healthy volunteers were subjected to increasing acceleration in low-velocity frontal impacts, randomly with head rotated either left or right. Bilateral EMG of the sternocleidomastoids, trapezii, and splenii capitis and acceleration of the sled, torso, and head were recorded. RESULTS: With either direction of head rotation at the time of impact, the muscle responses increased with increasing levels of acceleration (p < 0.01). The time to onset and peak electromyogram for all muscles progressively decreased with increasing levels of acceleration. With the head rotated to the left, the left trapezius generated 77% of its maximal voluntary contraction (MVC) EMG (more than double the response of other muscles). In comparison, the right trapezius generated only 33% of its MVC. The right sternocleidomastoid (25%) and left splenius muscles (32%), the ones responsible for head rotation to the left, were more active than their counterparts (the left sternocleidomastoid generated only 5% of its MVC EMG and the right splenius 9%). On the other hand, with the head rotated to the right, the right trapezius generated 71% of its MVC EMG, while the left trapezius generated only 30% of this value. Again, the left sternocleidomastoid (27% of its MVC EMG) and right splenius (28% of its MVC EMG), being responsible for head rotation to the right, were more active than their counterparts (the right sternocleidomastoid generated only 4% of its MVC EMG and the left splenius 13%). CONCLUSIONS: Frontal impacts tend to generate the most muscle activity in the ipsilateral trapezius muscle, increasing the risk of their injury.


Asunto(s)
Movimientos de la Cabeza/fisiología , Músculos del Cuello/fisiología , Lesiones por Latigazo Cervical/prevención & control , Aceleración , Adulto , Electromiografía , Humanos , Rotación , Lesiones por Latigazo Cervical/etiología
18.
J Orthop Res ; 23(5): 1105-11, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15908160

RESUMEN

OBJECTIVE: To determine the effect of occupant positioning on the response of the cervical muscles to whiplash-type posterolateral impacts. METHODS: Twenty healthy volunteers underwent left posterolateral whiplash-type impacts with the volunteers seated "out-of-position". Electromyograms of the cervical muscles were recorded. RESULTS: Whether having the trunk flexed to the left or right at the time of impact, the muscle responses were low in magnitude, showing a trend to increasing EMG responses with increasing acceleration (P>0.05). The time to onset and time to peak electromyogram for most muscles showed a trend to progressively decrease with increasing levels of acceleration. With the subject flexed to the left, all muscles generated 31% or less of the maximal voluntary contraction electromyogram. With the subject flexed to the right, all muscles generated 27% or less of their maximal electromyogram. In both positions, the trapezii were the most active (P<0.05). Thus, having the trunk flexed out of neutral posture at the time of impact produces a very low magnitude cervical muscle response compared to impacts with the trunk in neutral posture. CONCLUSIONS: In the absence of bodily impact, the flexed trunk posture appears to produce a biomechanical response that would probably decrease the likelihood of cervical muscle injury in low velocity posterolateral impacts.


Asunto(s)
Electromiografía , Músculos del Cuello/fisiología , Postura , Lesiones por Latigazo Cervical/fisiopatología , Fenómenos Biomecánicos , Humanos , Factores de Tiempo
19.
Spine J ; 5(2): 130-9, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15749612

RESUMEN

BACKGROUND CONTEXT: Knowledge is increasing about the electromyographic and kinematic response of the neck muscles to rear impact, and also recent information is available on the effect of a rear impact offset to the left (posterolateral). The effect of head rotation, however, at the time of rear impact is not known. PURPOSE: The purpose of this study was to examine the effects of head rotation to the left and right on the cervical muscle response to increasing low-velocity posterolateral impacts. STUDY DESIGN/SETTING: Twenty healthy volunteers were subjected to rear impacts of 4.7, 8.3, 10.9 and 13.7 m/s2 acceleration, offset by 45 degrees to the subject's left, with head rotation to right and left. METHODS: Bilateral electromyograms of the sternocleidomastoids, trapezii and splenii capitis were recorded. Triaxial accelerometers recorded the acceleration of the sled, torso at the shoulder level, and head of the participant. RESULTS: With the head rotated to the right, at an acceleration of 13.7 m/s2, the left sternocleidomastoid generated 59% and the right sternocleidomastoid 20% of their maximal voluntary contraction (MVC) electromyogram (EMG). Under these conditions, the remaining muscles (both splenii capitis and trapezius) generated 25% or less of their MVC. With the head rotated to the left, at an acceleration of 13.7 m/s2, the right sternocleidomastoid generated 65% and the left sternocleidomastoid only 11% of the MVC EMG. Under these conditions, again the remaining muscles had low EMG activity (27% or less) with the exception of the left trapezius which generated 47% of its MVC. Electromyographic variables were significantly affected by the levels of acceleration (p<.01). The time to onset and time to peak EMG for all muscles progressively decreased with increasing levels of acceleration, for both head rotation conditions. The kinetic variables and the electromyographic variables regressed significantly on the acceleration (p<.01). CONCLUSIONS: Direction of impact is a factor in determining the muscle response to whiplash, but head rotation at the time of impact is also important in this regard. More specifically, when a rear impact is left posterolateral, it results in increased EMG generation mainly in the contralateral sternocleidomastoid, as expected, but head rotation at the same time in this type of impact reduces the EMG response of the cervical muscles. Muscle injury seems less likely under these conditions in low-velocity impacts.


Asunto(s)
Movimientos de la Cabeza/fisiología , Contracción Muscular/fisiología , Músculos del Cuello/fisiopatología , Lesiones por Latigazo Cervical/fisiopatología , Aceleración , Adulto , Electromiografía , Femenino , Humanos , Masculino , Hombro/fisiopatología , Lesiones por Latigazo Cervical/etiología , Lesiones por Latigazo Cervical/prevención & control
20.
Clin Biomech (Bristol, Avon) ; 20(6): 553-68, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15927733

RESUMEN

Despite the fact that whiplash patients often report they had their head rotated or were in a twisted posture at the time of impact, the effect of these postures on the cervical muscle response to impact remains uninvestigated in impact studies. Prior impact studies have positioned the volunteers in the recommended driving position, for example, with head and trunk in a neutral posture. Using an approach of sled impacts with volunteers in very-low velocity impacts to describe the head kinematics and cervical muscle electromyography in response has provided a wealth of data. From this approach, the effect of varying impact direction and level of impact awareness can be discerned without subjecting the volunteers to injury. In part 1 of this review, a further series of results of impacts from eight directions is presented, revealing that the cervical electromyography response to whiplash-type impacts varies according to the presence and direction of head rotation. In part 2, additional data is summarised concerning whiplash-type impacts from 8 directions in the presence of trunk flexion. Contrary to a popular notion, head rotation or trunk flexion at the time of impact are factors that probably reduce injury risk. This data adds to attempts to approach an understanding of the human response to more complex scenarios of low-velocity road collisions.


Asunto(s)
Lesiones por Latigazo Cervical/fisiopatología , Aceleración , Fenómenos Biomecánicos , Electromiografía , Humanos , Músculo Esquelético , Rotación
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