Mechanical properties of bone as a function of position and orientation.
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Animals↗
Biomedical subjects
M H Pope
Publications and source records attributed to M H Pope.
Boot top fractures of the fibula.
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Adolescent↗
The fracture characteristic of bone substance.
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Animals↗
Biomechanical testing as an aid to decision making in low-back pain patients.
Frequently, the diagnosis of disease of the low back is a difficult matter due to the multitude of factors affecting the patient's symptoms. In this report an attempt is made to use biomechanical testing to objectify certain aspects of the diagnostic process. Our philosophy is that a biomechanical assessment is one of the disciplines that should be brought to bear on the low-back pain patient. A group of biomechanical tests has been developed by adding quantitative measurement techniques to certain standard clinical maneuvers: muscle testing, range of motion testing, and straight leg raising testing. Moire fringe topography is employed for studying posture. Results of application of these techniques to 117 patients and 10 controls indicate potential utility in the method for epidemiologic and clinical research.
Back Pain↗
Objective measurement of L4-5 instability. A case report.
Segmental instability as a consequence of disc degeneration is presented as an entity capable of producing low-back pain which responds to surgical stabilization with spinal fusion, and is illustrated with a case report. Data from lumbar radiographs were analyzed with a computer, and the position changes of the lumbar vertebrae were computed relative to the neutral positions of each. The results indicate that segmental instability is a complex disruption of intervertebral motion, consistent with the coupling behavior of the spine.
Adult↗
The relation between biomechanical and psychological factors in patients with low-back pain.
Behavioral factors are increasingly being recognized for their role in determining the course and outcome of low-back disorders. This paper examines the relation between behavioral variables, which include psychological symptoms and pain tolerance, and biomechanical variables. The majority of the 89 patients tested could be classified into two groups. One group was intolerant of pain and showed reduced spinal mobility, restricted straight leg raising, and altered flexor-extensor muscle balance. The other group was more tolerant of pain and did not show restriction of motion or muscle imbalance. Spinal mobility was also related to psychological symptoms. A model is proposed which points to a feedback between spinal motion and the patient's ability to cope with pain as one mechanism that determines return to a functional range of motion.
Adaptation, Psychological↗
Epidemiologic studies of low-back pain.
The records of 3920 patients (2068 females, 1852 males) entering a model family practice unit between 1975 and 1978 have been analyzed. Eleven percent of males and 9.5% of females reported an episode of low-back pain during that 3-year interval. The complaint of medically reported low-back pain was significantly related to occupational factors such as truck driving (p < 0.001), lifting, carrying, pulling, pushing, and twisting (P < 0.001 for all variables) as well as nondriving vibrational exposure (P < 0.001). Patients reporting low-back pain also reported more episodes of anxiety (P < 0.001) and depression (P < 0.001) and had more emotionally stressful occupations (P < 0.001). The mean number of pregnancies was greater in women with low-back pain (2.6) than in those without (1.6) (P < 0.001). The low-back pain sufferers were more likely to be cigarette smokers (P < 0.001), particularly when smoking was accompanied by a chronic cough (P < 0.001). This population is currently under prospective study to define the relevance of each of these risk factors to the complaint of low-back pain.
Adolescent↗
The functional topography of the sacroiliac joint.
This work analyzes the motion permitted by the topography of the sacroiliac joint surface. Gross contour profiles of the joint were recorded in the frontal and sagittal planes. Best-fit axes of rotation for each contour profile were obtained by statistical methods and were compared with those reported in the literature. There was considerable scatter of the locations of the most likely centers, or axes, of rotation in the frontal and sagittal planes. Were motion to occur about these axes, the articular surfaces would first separate by a distance sufficient to allow them to move over one another. Energy would be needed to separate the joint surfaces being pulled together by the surrounding ligaments. Thus, the sacroiliac joint may function as a shock- absorbing structure by virtue of energy absorbed in the ligamentous tissue.
Female↗
1980 Volvo award in clinical sciences. Assessment of patients with low-back pain by biplanar radiographic measurement of intervertebral motion.
Abnormalities of intervertebral joint motion including hypermobility, reduced mobility, torsional abnormality, and displacement of the center of rotation have been associated with degenerative change. However, measurement of these signs in plane X-ray films is handicapped by the three-dimensional motion and geometry of the spine. This study aimed to relate three-dimensional motion of the joints to their pathological state. We have used biplanar radiography to measure intervertebral motion during voluntary movements by patients with low back pain. Primary (or intentional) and coupled motions were measured by a refined technique, along with disc shear and facet joint motion. Abnormalities were found, especially in the "coupled" motions which were related to narrowed disc space, and to proximity to previous fusions. There was asymmetry of motion specific to joints with herniated nucleus pulposus.
Back Pain↗
Vibration and the human spine.
Vibrational effects have been found to be associated with increased frequency of low-back pain in various industries, and because of this the study herein reported was conducted to assess the physiologic response of the spinal system to sinusoidal vibrations. A device replicating industrial vibration was constructed and employed on healthy human volunteers to determine the stiffness, impedence, and resonant characteristics of the subjects. Three peaks of enhanced transmissibility corresponding to the resonant frequency of the spinal system were found. The greatest transmissibility of vibratory input occurs at the first resonant frequency (5Hz) where marked enhancement of vibrational input occurs as vibrations pass through the spinal system. A progressive stiffening of the system occurs in response to vibrational inputs of increasing frequency. The effects of posture, the Valsalva maneuver, and fatigue alter the normal response. Structures vibrated at the first resonant frequency have greater potential for damage.
Adolescent↗
The relationship between work history, work environment and low-back pain in men.
Interviews were conducted with 303 men to determine aspects of work history and working environment that are related to low-back pain. Respondents included no pain, moderate pain, and severe pain samples. Data were obtained for 150 variables including task frequencies, weights lifted, lifting postures, type of floor surface, type of chair support, pushing, pulling, and carrying activities, driving vehicles, and attributions of pain occurrence to particular situations. Univariate analyses showed difference among the three pain groups for lifting method, having had lifting instruction, stretching and reaching activities, amount of sitting and twisting in seat, pushing materials of varied weights, and contributions of pain onset. Multivariate regression analyses selected activities from (1) standing and lifting, (2) carrying, pushing, and pulling, (3) sitting, (4) driving vehicles, and (5) using vibrating equipment that jointly explained pain group variance. The significant variables from each domain were used in second-level multiple regressions to explain differences between no pain and pain, and between moderate and severe pain. Computed weights for pulling, lifting method, weight carried, reaching and stretching, chair support, number of times/day in-out of chair, and heavy vibration exposure explained 27% of variance between moderate and severe pain groups. Weights for automobile driving, number of times/day in-out of vehicle, number of lifts/day, maximum weight pulled, sitting with feet on floor, and exposure to heavy vibration explained 23% of the variance between no pain and pain groups.
Absenteeism↗
Body height changes from vibration.
A device for measuring body height is reported (SD, 1 mm). The change in body height before and after vibration and quiet sitting respectively was studied in eight men aged 22-44 years who were free of back pain. The vibration frequency was set at 5 Hz and the acceleration at 2 msec-2. Subjects were asked to report for testing within 2 hours after arising from bed. Body height was measured before and immediately after vibration or sitting exposure and the measurements were repeated at different intervals up to 2 hours after the experiment. Results show that exposure to vibration increases the overall creep response in most subjects. There is a great deal of variability in response between subjects, but most of them show a recovery to the average creep response within a 2-hour time interval.
Adult↗
Ski injuries and equipment function.
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Aptitude↗
Tibial shaft fractures in skiing.
A prospective study of all tibial shaft fractures produced during a single ski season in a Northern Vermont area is presented. Very little previous work concerning skiing-induced tibial fractures was present in the literature. Younger, lighter, and less skilled skiers are more frequently so injured. Spiral fractures account for 41.9% and boot top fractures for 37.9% of the total. Spiral fractures occurred by an internal rotation mechanism just as frequently as by external rotation, and were observed more frequently in slower moving skiers who were using shorter skis and lower, softer boots. Associated fibular fractures were commonly not observed in children. Tibial fractures occurring in skiing are the result of relatively low energy trauma. The level and type of fracture had little effect on healing time. With rare exceptions these fractures heal satisfactorily with nonsurgical techniques.
Adolescent↗
Knee injury in skiing. A multifaceted approach.
During the past four ski seasons, all 1,141 ski injuries which occurred in a large northern Vermont ski area were evaluated prospectively. Of these injuries, 21.6% involved knee ligaments and 18.6% involved sprains of the medial collateral ligament. Females sustained a disproportionately high incidence of Grade I medial collateral sprains, but suffered the more severe sprains at a rate similar to that of males. Individuals who were smaller, younger, less experienced, and less skilled sustained a higher incidence of Grade I injuries. Skiers suffering complete tears of the medial collateral ligament were no smaller, younger, or less skilled or experienced than our control population. Medial collateral sprains are produced primarily by external rotation and valgus forces. Two-mode release bindings are insensitive to several loading configurations which could produce knee sprains. Bindings which allow release in roll, shear, and twist at the heel, as well as twist at the toe and forward lean, appear to be necessary to protect the knee.
Athletic Injuries↗
Cyclic loading in knee ligament injuries.
The effect of cyclic loading on knee ligaments was studied both in vivo and in vitro. The compliance of the medial collateral ligaments of athletes participating in hockey, basketball, soccer, and downhill skiing was determined by using a specially built machine. Tests were conducted before and after participation in the various sports. Most subjects tested showed an increased compliance after their respective sporting activities. This observation was confirmed in the laboratory by imparting cyclic loading to 10 people under controlled conditions. The in vitro studies were conducted on the medial collateral ligaments of rats. These were tested to determine the effect of cyclic loading on the strength and stiffness of the ligaments. Results show a clear relationship between decreased stiffness or softening and a reduction in strength of the ligament. The amount of softening was related to the cyclic stress in the ligament.
Animals↗
Trends in skiing injuries. Analysis of a 6-year study (1972 to 1978).
The trends in skiing injuries showed a decrease during a study conducted over six seasons, 1972 to 1978, at a Vermont ski resort. Over 11,000 interviews were conducted and nearly 1,000 control skiers were evaluated. The injuries totaled 1,711 in 407,600 skier days. Upper body injuries (pelvis, trunk, neck, head, and upper extremities) totaled 713 (42%) and lower extremity injuries totaled 998 (58%). Eighty percent of the lower extremity injuries were classified as (potentially) equipment related. The overall injury rate decreased 41% (upper body, 25%; lower extremity equipment-related (LEER), 43%; and lower extremity nonequipment-related rate was down 71%). Knee sprains did not decline as rapidly as the tibial fractures and ankle sprains. An increase in the relative frequency of properly functioning equipment is primarily responsible for the decline in LEER injuries. Although the relative frequency of properly adjusted bindings is increasing, more than one-half of the equipment in use is still set higher than recommended. Cooperation between all individuals responsible for equipment design, manufacture, installation, and use must continue, if further improvements in alpine skiing safety are to be realized.
Age Factors↗
Upper extremity injuries in skiing.
In a six-year study, 1,711 ski injuries and 998 controls at Sugarbush North Ski Area were studied. Upper extremity injuries, which constituted 25% of all ski injuries, did not increase in frequency. Men and women were at equal risk of injury. When edging conditions were poor, upper extremity injuries were more common than lower extremity injuries. Forty percent of all upper extremity injuries involved the thumb (85% included injuries to the ulnar collateral ligament of the metacarpophalangeal joint). Twenty-five percent of 405 skiers interviewed had, at one time, injured their thumbs while skiing but only one-quarter of these reported their injury. Our study suggests that injury to the ulnar collateral ligament of the metacarpophalangeal joint may be the most frequent in skiing and that gripping the ski pole outside the strap may prevent these injuries.
Arm Injuries↗