Specific sites of bone expansion depend on the level of volleyball practice in prepubescent boys

Using human-in-the-loop optimization for guiding manual prosthesis adjustments: a proof-of-concept study

Introduction: Human-in-the-loop optimization algorithms have proven useful in optimizing complex interactive problems, such as the interaction between humans and robotic exoskeletons. Specifically, this methodology has been proven valid for reducing metabolic cost while wearing robotic exoskeletons. However, many prostheses and orthoses still consist of passive elements that require manual adjustments of settings. Methods: In the present study, we investigated if human-in-the-loop algorithms could guide faster manual adjustments in a procedure similar to fitting a prosthesis. Eight healthy participants wore a prosthesis simulator and walked on a treadmill at 0.8 ms-1 under 16 combinations of shoe heel height and pylon height. A human-in-the-loop optimization algorithm was used to find an optimal combination for reducing the loading rate on the limb contralateral to the prosthesis simulator. To evaluate the performance of the optimization algorithm, we used a convergence criterium. We evaluated the accuracy by comparing it against the optimum from a full sweep of all combinations. Results: In five out of the eight participants, the human-in-the-loop optimization reduced the time taken to find an optimal combination; however, in three participants, the human-in-the-loop optimization either converged by the last iteration or did not converge. Discussion: Findings from this study show that the human-in-the-loop methodology could be helpful in tasks that require manually adjusting an assistive device, such as optimizing an unpowered prosthesis. However, further research is needed to achieve robust performance and evaluate applicability in persons with amputation wearing an actual prosthesis.

A comparison of the associations between bone turnover markers and different sports fields: combat versus team sports

Sedentary life brings risks that include osteoporosis, while physical activity has many benefits for health in general and the skeletal system. Irisin is a hormone-like myokine regulated by mechanical force and it contributes to cortical and trabecular bone mineral density. This study aimed to investigate the effects of different types of sports on bone health by measuring elite athletes’ fibronectin type III domain 5 (FNDC5), N-terminal collagen type I extension propeptide (PINP), and C-terminal cross-linking telopeptide of type I collagen (CTXI) levels. Combat sports athletes, team sports athletes, and sedentary control subjects were enrolled. Serum levels of proteins were measured by ELISA. FNDC5 levels of elite athletes were higher compared to the sedentary controls (P=0.0014). The highest FNDC5 level was measured in wrestlers among all considered groups. The PINP levels of the athletes were also higher than those of the sedentary control group (P=0.1431). The highest PINP level was determined in boxers. The CTXI levels of the athletes were lower than those of the sedentary control (P<0.0001). The lowest CTXI level was seen in boxers. The FNDC5 and PINP levels of combat sports athletes were higher than those of team sports athletes (P=0.0134 and P=0.0262, respectively), while the CTXI levels of combat sports athletes were lower than those of team sports athletes (P<0.0001). Our results indicated that FNDC5, PINP, and CTXI levels are associated with physical activity. The effect of the exercises performed by athletes of specific sports on bone health has not been studied in much detail before. Combining different exercises for athletes of a particular sport may be more beneficial for bone health.

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

The aim of this longitudinal study was to examine the effects of 1-yr of volleyball practice on the bone mass development in the growing skeleton among prepubescent children. Twenty volleyball players and nine teen matched control boys (Tanner stage 1, at the start of the study) were followed over a 1-yr period. Bone mineral density (BMD, g/cm²), bone mineral content (BMC, g) were measured by dual-energy X-ray absorptiometry on the whole body, lumbar spine (L2–L4), legs, arms, femoral necks, hips and radii. At follow-up, in comparison with controls, volleyball players gained more BMD in whole body (4.5% vs 1.7%; p = 0.014), both nondominant and dominant arms (5.8% vs 1.1% p = 0.005, and 6% vs 2.1%; p = 0.003, respectively), both nondmoninat and dominant legs (9% vs 4.8%; p = 0.005 and 10.7% vs 6% p = 0.0025; respectively), dominant ultradistal radius (10.4% vs 0.9%; p = 0.005), dominant third distal radius (9.6% vs 3.71%; p = 0.023), dominant whole radius (7.4% vs 3.1%; p = 0.017), lumbar spine L2-L4 (9.9% vs 2.8%; p = 0.004), femoral neck (4.7% vs 1.6%; p = 0.034), trochanter (6% vs 1.5%; p<0.001) and total hip (6.1% vs 2.6%; p = 0.006). Volleyball players gained more BMC in both nondominant and dominant arms (25.1% vs 13.4%; p = 0.003, and 26.1% vs 15.6%; p<0.001 respectively), both nondominant and dominant legs (20.2% vs 14.5%; p = 0.004 and 23% vs 16%; p = 0.004, respectively), dominant ultradistal radius (22.4% vs 8.7%; p = 0.002), dominant third distal radius (20.9% vs 5.9%; p = 0.001), dominant whole radius (20% vs 13%), nondominant third distal radius (14.5% vs 5.9%; p = 0.001), nondominant whole radius (21.1% vs 12%; p = 0.002), lumbar spine L2-L4 (21.1% vs 13.7%; p = 0.007), femoral neck (25.9% vs 8.7%; p = 0.007), trochanter (23.5% vs 17.1%; p = 0.006), and total hip (16.3% vs 11.3%; p = 0.009) than controls. A close correlation was observed between the increment (Δ) of whole body lean mass and increased (Δ) BMD and BMC in whole body (r = 0.43, p<0.01, r = 0.73, p<0.001; respectively), lumbar spine (r = 0.54, r = 0.61, p<0.001; respectively), trochanter (r = 0.46, p<0.01, r = 0.35, p<0.05; respectively), and total hip (r = 0.53, p<0.01, r = 0.6, p<0.0001; respectively). In summary, 1-yr of volleyball practice has an osteogenic effect on bone mass in loaded sites in prepubescent boys.

Health Effects of Wrist-Loading Sports During Youth: A Systematic Literature Review

BACKGROUND

The benefits and risks of performing popular wrist-loading sports at a young age have not been investigated systematically. We aimed to evaluate positive and negative long-term wrist-related health effects of sports performance requiring repetitive wrist loading during youth.

METHODS

Six databases were searched for cohort and cross-sectional studies. Three investigators selected studies evaluating quantitatively measured health effects of upper extremities in athletes practicing wrist-loading sports (gymnastics, tennis, volleyball, field hockey, rowing, and judo) for minimally 4 months before the age of 18.

RESULTS

A total of 23 studies with 5 outcome measures, nearly all of moderate to good quality, were eligible for inclusion. Bone mineral density and bone mineral content were higher in athletes compared with controls and in tennis players' dominant arm. Mixed results were found for ulnar variance in gymnasts. Handgrip strength was greater in tennis players' dominant arm and in experienced gymnasts.

CONCLUSIONS

Wrist-loading sports performance during youth can promote bone strength in wrists and dominant handgrip strength, but evidence on the lasting of these effects and on prevalence of wrist joint degeneration in former young athletes is limited. For better counseling of young athletes and their parents, future studies with increased comparability are essential, for which recommendations are provided.

Judo Practice in Early Age Promotes High Level of Bone Mass Acquisition of Growing Boys' Skeleton

The current study aimed to exhibit effects of judo training for at least 2 yr on bone mass parameters in growing boys. Our population was composed of one hundred and thirty boys in tanner stage 1 and aged 10.52 ± 0.86 yr. Eleven judo players were therefore, excluded from the study because they do not have participate regularly to the judo training sessions during the last 2 yr. The resting sample was divided into two groups: 50 judo players (JU group) and 69 controls (C group). Bone mineral density (BMD), bone mineral content (BMC), and bone area (BA) were evaluated by using dual-photon X-ray absorptiometry on weight-bearing sites: the whole body, lumbar spine (L2-L4), legs, femoral necks and hips and on the non-weight bearing sites: arms and radiuses. Our findings displayed that judo participation was markedly associated with greater values of bone mass parameters in young judo players than control group. Accordingly, the BMD and BA results exhibited significant differences in the whole body, legs, dominant total hip, arms and both whole radiuses in addition to the dominant femoral neck, the non-dominant total hip and except the non-dominant whole radius for the BMC parameter. Additionally, data of the subject within t test has shown significant differences of bone mass parameters only in the non weight-bearing sites in the judo players without any obvious variation in the controls. Differences of BMD observed on the dominant arm and whole radius in addition to the increased BMC values showed in the dominant whole radius compared with their contra-lateral sites in judo players without any marked variation of BA parameters in all sites in both groups. In growing boys, judo practice was obviously associated with osteogenic effects in specific sites.

Analysis of Bone Mineral Density/Content of Paratroopers and Hoopsters

The different mechanical stimulus affects the bone mass and bone strength. The aim of this study was to investigate the effect of landing posture of the hoopster and paratrooper on the bone mass. In this study, 39 male participants were recruited including 13 paratroopers, 13 hoopsters, and 13 common students (control groups). Bone area (BA), BMD and BMC of calcaneus, and 1-5th of the metatarsus, hip, and lumbar spine (L₁-L₄) were measured by the dual-energy X-ray absorptiometry. Also, the vertical ground reaction forces (GRFs) of hoopsters and paratroopers were measured by the landing of 1.2 m 3D force platform. BA of hoopsters at the calcaneus, lumbar spine, and hip were significantly higher than the control group. The lumbar spine, hip, calcaneus, the 1st and 2nd metatarsals, BMC of paratroopers, and control groups were significantly lower than hoopsters. BMD of the lumbar spine, hip, and right and left femoral necks in hoopsters were significantly higher than the other participants. BMC and BMD of lower limber showed no significant difference between paratroopers and the control group. Besides, peak GRFs of paratroopers (11.06 times of BW) were significantly higher than hoopsters (6.49 times of BW). The higher GRF in the landing train is not always in accordance with higher BMD and BMC. Variable loads in hoopsters can improve bone remodeling and play an important role in bone expansions for trabecular bones. This will be considered by the method of training to prevent bone loss.

Bone Turnover Markers and Lean Mass in Pubescent Boys: Comparison Between Elite Soccer Players and Controls

The aim of this study was to examine the relationship between bone mass and bone turnover markers with lean mass (LM) in pubescent soccer players. Two groups participated in this study, which included 65 elite young soccer players who trained for 6-8 hours per week and 60 controls. Bone mineral density; bone mineral content in the whole body, lower limbs, lumbar spine, and femoral neck; biochemical markers of osteocalcin; bone-specific alkaline phosphatase; C-telopeptide type I collagen; and total LM were assessed. Young soccer players showed higher bone mineral density and bone mineral content in the whole body and weight-bearing sites (P < .001). Indeed, the total LM correlated with whole-body bone mineral density and bone mineral content (P < .001). There were significant differences within the bone formation markers and osteocalcin (formation)/C-telopeptide type I collagen (resorption) ratio between young soccer players compared with the control group, but no significant difference in C-telopeptide type I collagen was observed between the 2 groups. This study showed a significant positive correlation among bone-specific alkaline phosphatase, osteocalcin, and total LM (r = .29; r = .31; P < .05) only for the young soccer players. Findings of this study highlight the importance of soccer practice for bone mineral parameters and bone turnover markers during the puberty stage.

Handball Practice Enhances Bone Mass in Specific Sites Among Prepubescent Boys

This investigation's purpose is to focus on the effects of practicing handball for at least 2 yr on bone acquisition among prepubescent boys. One hundred prepubescent boys aged 10.68 ± 0.85 yr were divided into 2 groups: 50 handball players (HP group) and 50 controls (C group). Bone mineral density (BMD), bone mineral content (BMC), and bone area (BA) were evaluated by using dual-photon X-ray absorptiometry on the whole body, lumbar spine (L2-L4), legs, arms, femoral necks, hips and radiuses. Results showed greater values of BMD in both right and left femoral neck and total hip in handball players than in controls. In addition, handball players had higher values of legs and right total hip BMC than controls without any obvious variation of BA measurement in all sites between groups. All results of the paired t-test displayed an obviously marked variation of bone mass parameters between the left and right sides in the trained group without any marked variation among controls. Data showed an increased BMD of the supporting sites between the left and the right leg among handball players. However, "BMC" results exhibited higher values in the right than in the left total hip, and in the right total radius than in the left correspondent site. In addition, differences in the "BA" measurements were observed in the left total hip and in the right arm. Specific bone sites are markedly stimulated by handball training in prepubescent boys.

Volleyball and Basketball Enhanced Bone Mass in Prepubescent Boys

The aim of this study was to examine the effect of volleyball and basketball practice on bone acquisition and to determine which of these 2 high-impact sports is more osteogenic in prepubertal period. We investigated 170 boys (aged 10-12 yr, Tanner stage I): 50 volleyball players (VB), 50 basketball players (BB), and 70 controls. Bone mineral content (BMC, g) and bone area (BA, cm(2)) were measured by dual-energy X-ray absorptiometry at different sites. We found that, both VB and BB have a higher BMC at whole body and most weight-bearing and nonweight-bearing sites than controls, except the BMC in head which was lower in VB and BB than controls. Moreover, only VB exhibited greater BMC in right and left ultra-distal radius than controls. No significant differences were observed between the 3 groups in lumbar spine, femoral neck, and left third D radius BMC. Athletes also exhibited a higher BA in whole body, limbs, lumbar spine, and femoral region than controls. In addition, they have a similar BA in head and left third D radius with controls. The VB exhibited a greater BA in most radius region than controls and a greater femoral neck BA than BB. A significant positive correlation was reported between total lean mass and both BMC and BA in whole body, lumbar spine, total hip, and right whole radius among VB and BB. In summary, we suggest that volleyball and basketball have an osteogenic effect BMC and BA in loaded sites in prepubescent boys. The increased bone mass induced by both volleyball and basketball training in the stressed sites was associated to a decreased skull BMC. Moreover, volleyball practice produces a more sensitive mechanical stress in loaded bones than basketball. This effect seems translated by femoral neck expansion.

[Practice of martial arts and bone mineral density in adolescents of both sexes]

OBJECTIVE

The purpose of this study was to analyze the relationship between martial arts practice (judo, karate and kung-fu) and bone mineral density in adolescents.

METHODS

The study was composed of 138 (48 martial arts practitioners and 90 non-practitioners) adolescents of both sexes, with an average age of 12.6 years. Bone mineral density was measured using Dual-Energy X-ray Absorptiometry in arms, legs, spine, trunk, pelvis and total. Weekly training load and previous time of engagement in the sport modality were reported by the coach. Partial correlation tested the association between weekly training load and bone mineral density, controlled by sex, chronological age, previous practice and somatic maturation. Analysis of covariance was used to compare bone mineral density values according to control and martial arts groups, controlled by sex, chronological age, previous practice and somatic maturation. Significant relationships between bone mineral density and muscle mass were inserted into a multivariate model and the slopes of the models were compared using the Student t test (control versus martial art).

RESULTS

Adolescents engaged in judo practice presented higher values of bone mineral density than the control individuals (p-value=0.042; Medium Effect size [Eta-squared=0.063]), while the relationship between quantity of weekly training and bone mineral density was significant among adolescents engaged in judo (arms [r=0.308] and legs [r=0.223]) and kung-fu (arms [r=0.248] and spine [r=0.228]).

CONCLUSIONS

Different modalities of martial arts are related to higher bone mineral density in different body regions among adolescents.