Volleyball practice increases bone mass in prepubescent boys during growth: A 1-yr longitudinal study

Prevalence and risk factors of low bone mineral density in Chinese Han male patients with alcohol dependence

OBJECTIVE

To investigate the prevalence of low bone mineral density (BMD) along with its possible risk factors in male Han Chinese patients with alcohol dependence (AD).

METHODS

This retrospective, cross-sectional study included male patients with AD, classified into normal and low BMD groups according to bone densitometry T scores. Demographic and alcohol-related data, and routine laboratory parameters were compared between the two groups. Binary logistic regression analysis was employed to evaluate risk factors associated with low BMD, and correlations between the T-score and demographic, alcohol-related, and routine laboratory data were evaluated.

RESULTS

Among a total of 107 patients with AD included in the study, the prevalence of low BMD was 70.09% (75/107). Patients with low BMD were older, consumed more alcohol daily, and had higher lactate dehydrogenase (LDH) and lower Ca2+ levels than patients with normal BMD. Regression analysis revealed that increased daily alcohol intake, low serum Ca2+ levels, high serum LDH levels, and comorbid hypertension was related to low BMD in patients with AD. Further correlation analysis revealed a positive association between T-score and serum Ca2+ levels.

CONCLUSION

Increased daily alcohol intake, low serum Ca2+ levels, high serum LDH levels, and comorbid hypertension may be risk factors for low BMD.

Damage for gain: The useful damage of the Pitcher's paradox

Introduction

Sport-specific adaptations of the glenohumeral joint may arise in adolescent overhead athletes who begin high-performance sports early in life. Research mainly addresses overuse injuries, leaving gaps in prevention, with adults studied more than youths.

Objective

This study aims to investigate sport-adaptations of the glenohumeral joint in asymptomatic adolescent volleyball players to identify potential shoulder injury risk factors.

Design

Observational study.

Setting

Clinical screening campaign conducted at the Physical Medicine and Rehabilitation Unit of Policlinic Hospital in Catania, Italy.

Participants

Forty asymptomatic under-16 athletes were evaluated.

Interventions

Shoulder internal rotation (IR) and external rotation (ER), range of motion (ROM), total-rotation ROM, glenohumeral IR deficit (GIRD), general joint laxity using Beighton score, apprehension, relocation, O'Brian tests, and ultrasound (US) glenohumeral distance were tested bilaterally. Variables such as the player's position, the age they began the sport, limb dominance, weight, and height were also considered.

Results

The median US glenohumeral distance was at 0.42 ± 0.26 cm, which is consistent with the range found in non-dislocated shoulders of a healthy non-athletic population. The ER ROM was significantly greater in the dominant shoulder than the contralateral one (P = 0.0001), and there was a significant correlation between the ER ROM of attackers and their US glenohumeral distance (P = 0.0413). Furthermore, shoulder IR ROM and US glenohumeral distance were not significantly different between the dominant and contralateral limbs (P = 0.05). None of the athletes presented GIRD. Other tests, including the Beighton score, apprehension, and relocation tests, yielded no significant differences between the dominant and contralateral limbs.

Conclusions

Despite an increased shoulder ER in the dominant limb, the glenohumeral joint remains stable, suggesting that greater ROM in ER does not equate to instability in overhead athletes without hyperlaxity. Nevertheless, increased ER impacts glenohumeral distance in attacker volleyball players. This finding suggests that the shoulder morphological adaptation process starts early in attackers.

Correction: Volleyball practice increases bone mass in prepubescent boys during growth: A 1-yr longitudinal study

[This corrects the article DOI: 10.1371/journal.pone.0266257.].

Musculoskeletal health in children and adolescents

The purpose of this narrative review was to investigate the key determinants of musculoskeletal health in childhood and adolescence, with particular attention to the role of physical activity. First, we examined the importance of bone modeling and remodeling in maintaining the bone health and the integrity and mechanical characteristic of the skeleton. In addition, we reported the evidence on an appropriate calcium and vitamin D intake, as well as local load variation in achieving proper peak bone mass. Proteomic and transcriptomic studies identified the skeletal muscle "secretoma", consisting of several myokines involved in endocrine and paracrine functions. Among these, we explored the role of irisin, a myokine involved in the muscle-bone crosstalk, and in the regulation of metabolic pathways. It is known that physical activity during growing positively impacts on skeleton and can protect by bone loss in adulthood. However, there are still concerns about the optimal interval duration and exercise intensity, particularly at the pubertal growth spurt which represents a window of opportunity to increase skeletal strength. We reported data from clinical trials performed in the last 5 years analyzing the impact of the type and timing of physical activity during childhood on skeletal development. Finally, we reported recent data on the significance of physical activity in some rare diseases.