Relationship between static and dynamic foot postures in professional baseball players.

STUDY DESIGN: Observational study of static and dynamic foot postures in professional baseball players. BACKGROUND: Throughout the course of a professional baseball season, running, cutting, and sprinting activities can produce a breakdown in players' foot function, causing overuse injuries. OBJECTIVES: To investigate the relationship between static and dynamic foot postures; to determine the occurrence of abnormal foot postures in professional baseball players and the incidence of overuse injuries in the lower extremity; and to compare the foot postures of pitchers to those of positional players. METHODS AND MEASURES: The foot postures of 74 professional baseball players were evaluated at rest and during gait. Measures of static foot posture were obtained with a goniometer and included the subtalar neutral position, forefoot/rearfoot position, ankle joint dorsiflexion, tibial angle in standing, and calcaneal angle in standing. The FootTrak motion analysis system provided measures of dynamic foot posture (rearfoot supination and pronation) during the stance phase of gait. A questionnaire was completed by players who reported previous lower extremity injuries. The chi-square statistic was used to determine the associations between forefoot position (varus or valgus) and the amount of foot pronation during gait. RESULTS: The forefoot varus and calcaneal valgus in standing was significantly associated with the maximum pronation during the stance phase of gait. Of the 65 players who demonstrated excessive pronation (> 8 degrees), 28 (43%) also reported a previous lower extremity injury. No statistically significant difference occurred, however, between injured and uninjured players with respect to the mean values of static or dynamic foot posture. In addition, foot postures were not associated with a player's position. CONCLUSIONS: Selected measures of static rearfoot and forefoot postures may have value in predicting dynamic rearfoot movement during the stance phase of gait. Excessive pronation in the baseball players we studied was not found to be a significant contributing factor in the development of overuse injuries.

Attitudes toward standardized data collection.

BACKGROUND AND PURPOSE: Clinical databases will gain importance as physical therapists need to determine the effectiveness and justify the expense of treatment. Obstacles impeding participation in standardized data collection need to be identified and addressed to construct high-quality databases. SUBJECTS: Subjects were clinicians involved in patient care in a multisite physical therapy/occupational therapy practice that had initiated a standardized data collection program. METHODS: Questionnaires, asking about participation in the data collection project, were distributed to participating clinics. Factor analysis identified attitudes toward standardized data collection. Relationships between efforts to learn standardized methods, attitudes, clinic and clinician characteristics, and levels of participation in the project were investigated. RESULTS: Most respondents (66%) had made some effort to learn the standardized procedures. Five attitudes were identified: inconvenience, acceptance of operational definitions, automation, paperwork, and training. CONCLUSION AND DISCUSSION: Inconvenience of data collection and training in standardized methods need to be addressed to construct large, high-quality databases.

Smoking cessation and absence from work.

BACKGROUND: This study examines the relationship between smoking cessation and absence from work by analyzing data collected from a large sample of ex-smokers. In particular, it is hypothesized that if smoking cessation is of benefit for work attendance, the incidence of absence should be inversely related to the amount of time elapsed since smoking cessation. METHODS: A multivariate logit model of absence incidence is proposed which includes variables measuring the amount of time since smoking cessation. This model is then estimated using data collected from a sample of 4,812 ex-smokers as part of the 1989/1990 Australian National Health Survey. RESULTS: The estimated coefficients indicate that the probability of absence among ex-smokers is highest for those who only stopped smoking in the past year and progressively falls with the number of years since smoking cessation, with persons who last smoked at least 20 years ago found up to 4.5 times less likely to be absent from work than persons who ceased smoking during the previous year. CONCLUSIONS: Smoking cessation is not only associated with improved health outcomes, but also with improved behavioral outcomes, such as increased work attendance. However, such improvement is observed only over relatively long periods of time.

Smoking and absence from work: Australian evidence.

This study reports on research into the relationship between absence from work and smoking. A key feature of the study is the data, which come from the National Health Survey (NHS) undertaken in 1989/90 in Australia. Involving responses from more than 54,000 individuals, the NHS provides what is almost certainly the largest and most comprehensive data set available in the world today containing information on both absence and smoking behaviour. Moreover, the data permit controls to be applied for a large number of influences thought to have some bearing on work attendance. Logit models of absence incidence over a two week period are estimated, and smoking is consistently found to have a large and significant impact on absence. This impact, however, is not consistent across the sexes. The probability of a male smoker being absent from work is estimated to be 66% greater than that for a male who has never smoked. For females, the corresponding figure is just 23%. The findings also suggest that it is important to distinguish ex-smokers from other non-smokers, with the incidence of absence among ex-smokers being almost as high as that for current smokers. Finally, no evidence was uncovered to suggest that absence varied with the actual quantity of tobacco smoked, as measured by both the number of cigarettes smoked and estimated daily nicotine and tar intakes.

The effect of two types of foot orthoses on rearfoot mechanics.

Little experimental data exist regarding the comparative biomechanical of various foot orthoses. This study evaluated the comparative effect of biomechanical orthoses and over-the-counter arch supports on controlling rearfoot pronation. Twenty-four patients with forefoot varus deformity were studied while walking on a treadmill. Two-dimensional, videotape motion analysis was used for studying rearfoot mechanics with three experimental conditions: 1) shoes only, 2) shoes plus arch supports, and 3) shoes plus biomechanical orthoses. The variables studied were: maximum pronation, calcaneal eversion, maximum pronation velocity, time-to-maximum pronation, and total pronation. No difference was noted in maximum pronation, calcaneal eversion, and total pronation between the three conditions. The data for maximum pronation velocity and time-to-maximum pronation were not reliable. Based on the results of this study, padded arch supports nor biomechanical orthoses can be preferentially recommended for their ability to control maximum pronation, calcaneal eversion, and total pronation during walking. Additional research is necessary to: 1) identify the biomechanical effects that are responsible for the clinical success of foot orthoses, and 2) determine better designs for controlling rearfoot movement.

The frontal plane relationship of the forefoot to the rearfoot in an asymptomatic population.

Physical therapists use biochemical orthotics to treat symptoms attributed to structural abnormalities of the feet. The purpose of this study was to determine the prevalence of forefoot varus, valgus, and neutral positions in a healthy population, and to compare forefoot positions between genders, legs, and age groups. Nonprobability sampling was used to obtain 120 healthy subjects. A repeated-measures, one-group design was used. A forefoot measuring device and a goniometer were used to measure the forefoot-rearfoot frontal plane relationship. Of the 234 measured feet, 86.67% had a varus, 8.75% had a valgus, and 4.58% had a neutral forefoot-rearfoot relationship. No significant difference in position was found between genders or legs within subjects. A certain amount of forefoot varus or valgus may be characteristic of a healthy population; however, future studies should include children and adolescents to determine if forefoot positions are acquired or congenital.

Effects of three different posting methods on controlling abnormal subtalar pronation.

BACKGROUND AND PURPOSE: The purpose of this study was to determine the effects of different orthotic posting methods on controlling abnormal foot pronation during ambulation. SUBJECTS: Twenty-two individuals with forefoot varus deformities of at least 8 degrees (13 women, aged 21-40 years, and 9 men, aged 20-50 years) participated in the study. The female subjects had an average height and weight of 162.6 cm (64 in) and 55.3 kg (122 lb), and the male subjects had an average height and weight of 175.3 cm (69 in) and 80.7 kg (178 lb). METHODS: The subjects were examined with a computerized video motion analysis system. A control trial consisted of walking at 4.0 km/h in running shoes. Experimental trials included walking at 4.0 km/h in running shoes with unposted orthotic shells and with orthotic shells posted in the forefoot, the rear foot, and both forefoot and rear foot. RESULTS: Maximal calf-to-calcaneus and calcaneus-to-vertical angles were decreased more by orthoses posted in both the forefoot and the rear foot than by orthoses posted only in the forefoot. No difference in maximal calf-to-calcaneus and calcaneus-to-vertical angles were found with combined forefoot and rear-foot posting compared with posting in the rear foot alone. The maximal calf-to-calcaneus angle was decreased by orthoses posted in any of the three methods and by the orthotic shell alone when compared with shoes alone. The maximal calcaneus-to-vertical angle was decreased by orthoses posted in any of the three methods, but not by the orthotic shell alone when compared with shoes alone. CONCLUSION AND DISCUSSION: Clinicians should consider combined posting or rear-foot posting alone when maximal control of rear-foot frontal-plane pronation is desired, though forefoot posting alone and the orthotic shell also provide control of rear-foot frontal-plane pronation.

Effects of strength training on throwing velocity and shoulder muscle performance in teenage baseball players.

Exercise protocols designed to improve muscle function and athletic performance are continually developed and revised, often without published research supporting their efficacy. This study compared the effects of isokinetic (IKN) and accommodative isotonic training in the individualized, dynamic, variable resistance (IDVR) mode. Twenty-seven teenage baseball players were tested isokinetically for dominant shoulder rotational peak torque and power and for throwing velocity. They were then randomly assigned to 5 weeks of IKN training, IDVR training, or a control group of no training. Following the training period, pretest protocols were repeated. Analysis of variance of differences in means and Newman-Keuls post hoc tests showed statistically significant increases in throwing velocity and external rotator torque in the IDVR group but not the IKN group. External rotator power improved in both groups. Internal rotator torque and power were not improved in either group. Results suggest that IDVR may be more effective than IKN training in improving throwing velocity and external rotator torque production. Clinicians should consider using IDVR protocols in improving shoulder muscle function and throwing performance. J Orthop Sports Phys Ther 1992;15(5):223-228.

Isokinetic evaluation of shoulder rotational strength between the plane of scapula and the frontal plane.

The purpose of this study was to determine whether shoulder rotational strength was greater in the plane of the scapula or the frontal plane. Isokinetic shoulder rotational strength was evaluated in 20 subjects. Using the Merac (Universal Gym Equipment, Inc., Cedar Rapids, IA), test data was gathered in the right shoulders, in 45 degrees abduction, at a speed of 60 deg/sec, in the plane of the scapula and the frontal plane. Each subject returned within 1 week for retests to establish reliability. The average correlational coefficient across tests was 0.87. The Merac computer system was used to analyze data. Mean and standard deviations for peak torque to body weight were calculated. A paired t-test was used to examine the difference in the means for internal and external rotation between the two positions. The results indicated no significant difference between the two positions for shoulder internal rotational strength values. However, shoulder external rotational strength values in the plane of the scapula were statistically significantly higher than in the frontal plane (P less than 0.001). These preliminary results suggest isokinetic strength training and testing may be preferable in the plane of the scapula rather than the frontal plane.

Preseason screening of the lumbar spine.

The author proposes a step-by-step method of lumbar spine examination which can be incorporated into the large scale preseason athletic participation screening process. This paper lists and describes examination techniques which can be administered quickly and accurately to large numbers of athletes in succession. In addition, the paper delineates two levels of proficiency required to perform the examination, outlines a practical format, and discusses general and specific precautions and contraindications to participation. J Orthop Sports Phys Ther 1981;3(1):6-10.