Measurement of various intensities of physical activities and categorization of "Locomotive" and "Household" activities provide a subject-specific detailed assessment.

This study aimed to compare the physical activity (PA) measured by a wearable sensor device (WSD) and the step count measurement, and to investigate the association between PAs and lifestyle. Data of 301 participants were collected from March 2019 to March 2021. Step counts, sedentary behavior, performance time of light/moderate/vigorous PA, METs × hour of "Locomotive" and "Household" categorized activities, and energy expenditure (EE) were measured by the WSD, respectively. Furthermore, the participants were classified into student, standing worker, and sitting worker groups. Data were analyzed using the Steel-Dwass and Pearson correlation coefficient tests. The correlation between the performance time of each PA and step count was weak, except for moderate PA. "Household" EE and step count also had a weak correlation. In the comparison of lifestyle, there was a significant difference in the mean performance time of each type of PA between the groups. Additionally, the standing worker and sitting worker groups had a significant difference in METs × hour of "Household" activities, indicating that the difference between the occupations is reflected in "Household" activities. The WSD measurement can be used to evaluate detailed individual PA, whereas the step count measurement showed weakness in the PA estimation.

The relationship between clinically measured hip rotational motion and shoulder biomechanics during the pitching motion.

OBJECTIVES: To examine how clinically measured hip motion is related to shoulder biomechanics during the pitching motion. DESIGN: Cross-sectional. METHODS: Bilateral hip rotational range of motion was measured clinically among 34 collegiate baseball pitchers. External rotation torque and maximum horizontal adduction range of motion of the throwing shoulder were measured using a three-dimensional, high speed video capture system. RESULTS: Separate standard multiple regression analyses showed that the total hip rotational range of motion of the lead leg had a significant relationship with shoulder external rotation torque during the throwing motion (r=0.56, P=0.003). Both lead leg hip external rotation range of motion (r=-0.39, P=0.02) and internal rotation range of motion (r=0.42, P=0.009) made significant contributions to this dependent variable. Lead leg external rotation range of motion also had a significant negative relationship with shoulder horizontal adduction range of motion (r=-0.36, P=0.04). The total rotational range of motion of the trail leg had a significant relationship with shoulder horizontal adduction range of motion (r=0.43, P=0.04). However, trail leg external rotation range of motion was the only significant contributor to this relationship (r=-0.35, P=0.04). No other significant relationships were noted (r<0.37, P>0.11). CONCLUSIONS: Our results demonstrate that altered hip rotational range of motion, measured clinically, has a direct effect on the amount of external rotation torque and horizontal adduction range of motion of the shoulder during the throwing motion.

Thoracolumbar range of motion in baseball pitchers and position players.

INTRODUCTION/BACKGROUND: Optimal baseball throwing mechanics require a significant contribution of thoracolumbar motion, particularly in the sagittal and transverse planes. This motion is key for proper transmission of forces from the lower to upper extremity, thereby minimizing a throwing athlete's risk of injury and maximizing athletic performance. PURPOSE: To define the active-assisted thoracolumbar ROM of both baseball pitchers and position players and to compare these motions both within and between groups. METHODS: Fifty-six asymptomatic, collegiate and minor league baseball pitchers and 42 position players volunteered to participate. Active-assisted thoracolumbar flexion, extension, and bilateral rotation ROM, were measured in a standing position, using two bubble inclinometers. Two-tailed t tests were used to determine differences in ROM between and within the pitchers and position players. RESULTS: The pitchers had significantly more rotation to the non-throwing arm side as compared to the position players (p = .007, effect size = .61). The pitchers also had more rotation to the non-throwing arm side as compared to their throwing side (p = .006, effect size = .47). There were no other significant differences between the pitchers and the position players (p > .53). Furthermore, the position players did not have a side-to-side rotation difference (p = .99). CONCLUSIONS: Pitchers have a greater amount of rotation ROM towards the non-throwing arm side as compared to position players. Pitchers also have a greater amount of rotation ROM to the non-throwing arm side as compared to their throwing side rotation. Because pitchers often present with posterior shoulder tightness and subsequent altered shoulder horizontal adduction and internal rotation ROM, the increase in non-throwing side rotation ROM may occur in response to these adaptations. More specifically, this increase in non-throwing side trunk rotation ROM may allow such athletes to bring the arm across the body during the follow-through phase of the throwing motion despite posterior shoulder tightness. However, future research is necessary to investigate this relationship. Based on these results, clinicians should consider these thoracolumbar ROM adaptations in the prevention, evaluation, and treatment of baseball players. LEVEL OF EVIDENCE: 2b.