Musculoskeletal and neuromuscular conditions of instrumental musicians.

Performing Arts Medicine is a broad field that includes the study of medical conditions and injuries incurred by dancers, instrumental musicians, and vocalists. This article summarizes the most relevant literature of approximately the past 10 years concerning the musculoskeletal and neuromuscular conditions of musicians. A literature search was done for relevant articles in English by physicians or scientists. Some older, but fundamental, articles are included; incidental case reports were excluded to the extent possible. Included were articles on incidence, prevalence, pathophysiology, diagnosis, treatment, and biomechanical studies in musicians. Although nearly all of these conditions are the same ones seen in the general work force, it is clear that their occurrence patterns in the professional musician are unique, as is their impact on the life and livelihood of the patient. The content of the Arts Medicine literature does not permit a truly critical review. Research in the last 10 years appears not to have been done in a true blinded, random case-controlled fashion. Many authors support their statements with only their respective clinical experiences. The research cited here includes 58 series, 9 case studies, 5 surveys, 2 pre/post intervention studies, and 1 double-blind crossover clinical trial.

Analysis of upper-extremity performance in athletes and musicians.

Injuries can result from direct or indirect trauma and overuse in sports and the performing arts. These injuries occur when the objective exceeds the physiologic tolerance. Biomechanics analysis enables the estimation of the capacities of the body as well as the loading environment encountered by the tendons, muscles, bones, and joints during various types of sports and musical activities.

A comparison of nonweight-bearing and weight-bearing radiographs of the foot.

This study compares the standardized measurements of the foot in nonweight-bearing and weight-bearing radiographs. Both normal and hallux valgus patients were studied. The results show that some changes thought to occur with weight-bearing cannot be consistently demonstrated. Obtaining both weight-bearing and nonweight-bearing views may not be routinely indicated in all patients.

Postural kinematics of trumpet playing.

This paper examines the effects of anthropometry on body posture of trumpeters playing in standing position. Sixteen virtuosi trumpeters were photographed while hitting three notes (low C, high F and high F sustained) during performance of musical tasks. Initial standing posture and anthropometric data were recorded. Six body segment angles were computed and a vectorial sum was obtained to describe whole body posture in neutral and playing conditions. Horn angle and dental overbite were also computed. Earlier results showed that the musical task has no effect on playing posture. One-way ANOVA showed notable differences between the neutral posture and the note-related playing postures. A multiple regression model showed that in addition to the note effect, anthropometric variables, mainly neck length, explain the changes in playing posture. Horn angle is determined by the dental overbite. The importance of the anthropometric variables in playing the more demanding notes indicate that anthropometry may act to constrain trumpeters' performance.

Musculoskeletal demands on flamenco dancers: a clinical and biomechanical study.

The flamenco dancer acts on the floor like a drummer. The percussive footwork and vibration patterns created during dancing impose unusual demands on the musculoskeletal system. This study investigated the clinical and biomechanical aspects of this task. Using the electrodynogram and skin-mounted accelerometers, foot pressures as well as hip and knee vibrations were recorded in 10 female dancers after a thorough clinical evaluation. A health questionnaire was also distributed to 29 dancers. Foot pressures and acceleration data reveal the percussive nature of the dance. Some clinical findings, like calluses, are related to pressure distribution. Urogenital disorders, as well as back and neck pain, may be related to the vibrations generated by the flamenco dance form. The hip joint seems to absorb most of the impacts. "Vibration-pressure" diagrams are suggested as a useful tool for evaluating a dancer's biomechanical behavior, as well as the effect of floors and footwear on this behavior.

Basal osteotomy of the fifth metatarsal with intermetatarsal pinning: a new approach to tailor's bunion.

The direct approach to the fifth metatarsophalangeal joint for the treatment of metatarsus quintus valgus often has been unsuccessful, mainly because of technical difficulties in the osteotomy of the narrow fifth metatarsal neck and the fixation of the unstable head fragment. Complications such as delayed union, nonunion, or recurrence have been reported. This paper describes a surgical technique for optimal correction of this deformity. The technique has a biomechanically sound fixation and a shortened bone healing time with minimum complications. Results of 12 patients presenting severe deformities are reported, with 1-year average follow-up.

Occupational biomechanics of athletes and dancers: a comparative approach.

Muscle strains represent more than a third of all injuries in both dancers and athletes. Although often overlooked, anatomic variations play an important role in the etiology of these injuries, as does strength imbalance between agonists and antagonists. The incidence of spondylolysis is unusually high in ballet dancers and certain athletic groups, such as gymnasts, javelin throwers, and weight-lifters. Mechanical factors play a major role and can be exacerbated by congenital abnormalities. Various permanent adaptive musculoskeletal changes have been described both in dancers and athletes, especially those that start at a very young age. Task-related adaptive changes can also be seen in isokinetic strength measurements of various muscle groups, such as the spine muscles of Flamenco dancers. Shoes and floor surfaces can be directly responsible in part or in whole for many sports and dance injuries. "Vibration-pressure" diagrams are suggested as an objective way to document their effect on biomechanical behavior.

Kinematics of the first metatarsophalangeal joint.

The kinematics of both the first metatarsophalangeal joint and the articulation of the hallux sesamoid bones with the metatarsal head were investigated with fifteen fresh-frozen below-the-knee amputation specimens using a radiographic technique. Six feet were of normal structural anatomy, six displayed hallux valgus, and three had hallux rigidus. Normal specimens demonstrated an average total range of motion in the sagittal plane of 111 degrees, with about 76 degrees of dorsiflexion and 34 degrees of plantar flexion. The abnormal specimens revealed a decreased total arc of motion, with a limitation of plantar flexion in feet with hallux valgus and a loss of dorsiflexion in feet with hallux rigidus. Motion analysis of the normal metatarsophalangeal joints demonstrated minimum scattering of instant centers of rotation. This was in contrast to the diseased articulations, which displayed markedly displaced instant centers of rotation located eccentrically about the metatarsal head. Surface motion in the normal joints was characterized as tangential sliding from maximum plantar flexion to moderate dorsiflexion, with some compression at maximum dorsiflexion. The feet with hallux valgus and the feet with hallux rigidus displayed distinctive patterns of distraction and jamming throughout specific portions of the range of motion in the sagittal plane. Motion of the metatarsophalangeal joint in the transverse plane concomitant with motion in the sagittal plane, which has been hypothesized by other investigators, was confirmed and quantified in this study. The feet with hallux rigidus displayed a reduction in this motion.(ABSTRACT TRUNCATED AT 250 WORDS)

The lifting stress calculator.

The Lifting Stress Calculator is a microprocessor-based device, programmed to select from a group of workers the one best suited for a specified lifting task. It also prompts this worker with the ideal position for him to lift the load in question. The concept is based on a theoretical study that deals with lifting as a total body exertion. The goal of this device is to educate the worker for better prevention of lifting injuries by minimizing the loads on the body.

Model for static lifting: relationship of loads on the spine and the knee.

An experimental study based on a trigonometric, anthropometric model, was conducted on thirty-five healthy subjects to determine the relationship between knee and back forces during symmetric sagittal plane lifting. Total joint reaction forces for the knee and the back, along with their compressive and shear components, were calculated for each subject, as a function of the knee, back and ankle angles. The shear component was significantly higher in females than in males; the compressive component was significantly higher in males. Strong inverse correlations were found between the back and the knee forces on all subjects. Strong correlations were also found between subject anthropometry and minimum and maximum joint reaction forces. The magnitudes of both back and knee joint reaction forces should be considered in recommending the lift type and position, based upon individual worker anthropometry, and size and weight of the load to be lifted.