Risk factors for injuries along an infantry commanders course.

To determine the influence of prevention programme on somatosensory ability in combat soldiers during 14-weeks of an infantry commanders course, two cohorts were recruited (INT-group, n = 196; CONT-group, n = 169). Soldiers were tested pre-and post-course for anthropometric measurements, proprioceptive ability, dynamic postural balance, and filled CAIT questionnaire. The INT-group performed injury prevention exercises and the CONT-group continued with their routine physical fitness lessons. All musculoskeletal injuries were recorded along the course. In the CONT-group 24.2% and in the INT-group 19.9% suffered injury during the course. The rates of injuries were not significantly different between groups (χ2(1) = .677 p = .411). Previous injury (OR = 3.349, 95% CI = 1.283-8.740), pre-course BMI (OR = 1.216, 95% CI = 1.064-1.389), and pre-course proprioception ability (OR = .870, 95% CI = .810-.935) were factors associated with injury in the CONT-group. Pre-course proprioception ability (OR = .769, 95% CI = .699-.846) and pre-course CAIT score (OR = .087, 95% CI = .027-.276) were factors in the INT-group. Soldiers who received injury prevention exercises had a similar prevalence of total musculoskeletal injuries as those who did not receive these exercises. Risk factors for injuries were different in the two groups.

Is there an association between joint range of motion and muscle strength in young female dancers? And, does it depend on the effects of age and menarche?

Aiming to determine the association between joint range of motion (ROM) and muscle strength; and, the effect of age and menarche on those two factors; 132 pre-and post-menarche dancers, aged 12-14 years were assessed for joint ROM and for muscle strength at the hip, knee and ankle and foot joints. En-pointe ROM was significantly correlated with ankle plantar-flexors' (r = -.184) and with ankle dorsiflexors' muscle strength (r = -.221). Hip external rotation ROM was significantly correlated with knee extensors' strength (r = -.263). Pre-menarche dancers had higher joint ROM compared with post-menarche dancers; yet, dancers at post-menarche were stronger compared to dancers at pre-menarche. The slope coefficient was negative at the age of 12 in hip external rotation and in en-pointe (-0.80 and -0.52, respectively) and became steeper with age (age 13: -3.52 and -3.28, respectively; age 14: -6.31 and -4.42, respectively). Along maturation, dancers with high joints ROM showed reduced muscle strength. Pre-menarche dancers have higher joint ROM, yet reduced muscle strength, compared with post-menarche dancers. As the association between joint ROM and muscle strength might be involved with growth and development, young dancers should be screened along pubertal stages in order to decide the correct curricula and to prevent future injuries.

The Function of the Proprioceptive, Vestibular and Visual Systems Following Fatigue in Individuals With and Without Chronic Ankle Instability.

To maintain postural balance, the proprioceptive, vestibular, and visual systems continuously provide body position and movement data to the central nervous system. In this study, our main aim was to examine, for the first time, the influence of anaerobically or aerobically induced fatigue on these separate functions in persons with and without chronic ankle instability (CAI). We obtained assessments pre- and post-fatigue protocols from 60 physical education students (Mage = 24.3, SD = 3.4) Twenty-seven students had CAI, and 33 students did not have CAI). To measure proprioception, we used the AMEDA device; for vision, we used near point of convergence (NPC); and, for vestibular function, we used subjective visual vertical (SVV). We found a pre-post proprioception (AMEDA) effect in the aerobic group (p < .001), and a visual (NPC) effect in both anaerobic and aerobic participant groups (both p < .001). There were no visual system (NPC) fatigue effect differences among aerobic or anerobic participants who had or did not have CAI (p = .047); there was a significant aerobic fatigue effect on proprioception (AMEDA) (p = .010) that favored participants without CAI. There was a significant interaction effect between time of testing and CAI for visual (NPC) (p = .003) in the aerobic group only. In both the anaerobic and aerobic groups, post-fatigue vestibular function (AMEDA) was significantly lower for those with than those without CAI (anaerobic: p = .030; and aerobic: p =.016). Thus, post-fatigue, participants with CAI showed worse proprioceptive, visual, and vestibular function than those without CAI. Future investigators should further examine each movement sense system in individuals with CAI.

Achilles Tendon and Patellar Tendon Structure in Combat Soldiers Following Prevention Exercises.

INTRODUCTION: Military training that increases physical stress on musculoskeletal morphology also increases the risk of orthopedic injuries. Somatosensory prevention programs that reduce stress and improve functionality could be beneficial for better organization of tendon structure. The aim of this study was to investigate the impact of a somatosensory prevention exercise on the tendon structure (percentage of echo-type fibers; A-P and M-L diameters and cross-sectional area) of the Achilles tendon and patellar tendon among combat soldiers. MATERIALS AND METHODS: These tendons of male Infantry soldiers aged 18-21 were screened before and after a 14-week training course. The intervention group, who performed preventative exercises, included 108 soldiers (BMI = 23.85 ± 2.76), while the control group, who participated in the same military course without these exercises, included 98 soldiers (BMI = 24.26 ± 4.03). Ultrasound scanning for tendon structure included percent of echo-type I-IV fibers, A-P diameter, M-L diameter, and cross-sectional area parameters. RESULTS: Time by group interaction was found for echo-type I and II in both tendons. No significant differences were found between the two groups in the pretesting percentage of echo-type IV fibers of the Achilles tendon (P = .522), in echo-type III fibers of the Achilles tendon (P = .833), and echo-type IV fibers of the patellar tendon (P = .162). Greater pre-post differences in echo-type III and IV fibers were found in the control group compared with the intervention group for both the Achilles tendon (P = .021, P = .002) and the patellar tendon (P < .001, P < .001). CONCLUSION: Increased damaged fibers (echo-type III and IV) of both tendons were found among the control group, yet not among soldiers who performed prevention exercises.

Another Look at Fatigued Individuals with and without Chronic Ankle Instability: Posturography and Proprioception.

Fatigue can impair function of the three sensory systems (vestibular, visual, and somatosensory) that control postural balance. Yet impairment may be greater among individuals with than those without chronic ankle instability (CAI). The present study used posturography assessment to extend previous findings demonstrating reduced function of the three systems in CAI participants following fatigue. Our aim in this study was to examine the influence of anaerobic and aerobic protocols on the function of these three sensory systems in individuals with and without CAI. We assessed 60 healthy physical education students (Mage = 24.3, SD = 3.4) by a Tetrax® Posturography device for Stability-Index and Fourier-frequencies [low sway (F1) visual input, medium-low sway (F2-F4) vestibular input, medium-high sway (F5-F6) somatosensory input] and by the Active Movement Extent Discrimination Assessment (AMEDA) for active ankle somatosensory ability, before and after performing anaerobic or aerobic protocols. Among participants, 45% were identified with CAI. We found significant Time effect (pre-post), CAI effect, and CAI X Time interactions for Fourier frequencies, Stability-Index, and AMEDA scores, indicating greater pre-post deterioration for those with CAI compared to those without CAI (p < .05). CI (95%) showed that, although there was a Time effect for F1, F2-F4, and F5-F6, only F5-F6 frequencies (i.e., somatosensory input) showed the CAI effect and the Time X CAI interaction. Thus, participants with and without CAI showed reduced visual, vestibular, and somatosensory ability following fatigue. While we found greater deterioration in both passive and active somatosensory ability (F5-6 and AMEDA) among individuals with CAI compared with those with no-CAI, we recommend intervention programs for improving vestibular abilities following fatigue in both those with and without CAI.

Common genetic basis of ALS patients and soccer players may contribute to disease risk.

OBJECTIVE: The aim of the present study was to determine the prevalence of the ACSL A/G single nucleotide polymorphism among athletes and patients with amyotrophic lateral sclerosis (ALS). ALS is a progressive neurodegenerative disorder of motor neurons that leads to paralysis and death usually within 3-5 years from onset. Previous epidemiological studies reported a higher risk of ALS among soccer players. The ACSL (long-chain-fatty-acid-CoA ligase 1) gene codes the long-chain fatty-acid-coenzyme A ligase family that plays a key role in lipid biosynthesis and fatty acid oxidation. The ACSL A/G polymorphism is associated with endurance trainability. METHODS: One hundred and seventy-eight ALS patients, 172 athletes (60 soccer players, 112 middle- and long-distance runners), and 111 nonathletic controls participated in the study. Genomic DNA was extracted from blood or buccal cells according to the salting-out procedure. Genotypes were determined using the TaqMan allelic discrimination assay. RESULTS: The prevalence of the ACSL AA genotype was significantly higher among soccer players (35.0%) and ALS patients (39.3%) compared to runners (16.1%) and controls (18.0%). However, ALS GG carriers had a higher mortality rate. CONCLUSION: We postulate that soccer players and ALS patients carry a common genetic predisposition that is related to impaired fatty acid utilization. Moreover, while the A allele might be associated with a genetic predisposition toward ALS, especially among soccer players, the G allele might be associated with disease severity. Further research is needed in order to explore the role of the ACSL rs6552828 polymorphism in ALS.

Predictors of Future Walking Speed: A 12-Month Monitoring Program.

The purpose of the current study was to identify significant predictors of walking speed (WS) among community-dwelling older adults, as it is one of the most representative measures of functioning in their daily lives. Seventy-seven (24 adult men, 26 adult women, and 27 older-adult women) community-dwelling older adults (73.7 ± 4.9 years) performed two assessments, over a 12-month period. Several physical, cognitive, and psychological tests were performed, as well as assessing the preferred WS. Multiple linear regression, stratified by gender, was used to identify significant predictors of future WS. For the adult men, walking and functional performances at the first assessment predicted 71.9%; for adult women, reaction time, walking, and balance performance predicted 64.4%; and, for the older-adult women, fast walking and reaction time predicted 48.2% of the variance of future WS. Clinicians should consider including different exercises for each group of older adults to evaluate and preserve functional abilities.

The Influence of a 14-Week Infantry Commanders Courses on the Achilles Tendon and Patellar Tendon Structure.

INTRODUCTION: Alternated tendon structure may raise stress to the musculoskeletal structures and may increase the potential for overuse injury. Screening the tendon structure of soldiers pre- and post-participation in a strenuous combat course is essential. The aim of the present study was to investigate the influence of a 14-week infantry commanders courses on the Achilles tendon (AT) structure and patellar tendon (PT) structure in combat soldiers. MATERIALS AND METHODS: Ninety-eight participants from an infantry commanders course were screened pre- and post-course for the AT and PT structures, using ultrasonographic tissue characterizaton (UTC) imaging to capture a 3D structure of four echo-type fibers (I-IV). RESULTS: In both tendons, the mean relative frequency of echo-type I fibers significantly decreased from pre- to post-testing, with a significant increase in the relative frequency of echo-types II, III, and IV fibers. In the AT, 60.2% of the subjects showed positive differences (between pre- and post-testing in the echo-type III + IV fiber ("worsened" tendon structure), whereas in the PT, 92.2% of the subject showed an increased frequency. No significant correlation (r = 0.108; P = .324) was found between the differences of echo-type III + IV fibers of the AT and that of the PT. CONCLUSIONS: Loads to the musculoskeletal structures along the combat course increased the mean relative frequency of the "reduced" echo-type fibers (III + IV) in both the AT structure and the PT structure. Yet, whereas in the AT around 40% of the soldiers showed an improved tendon structure along the course, in the PT less than 10% of the soldiers showed that improvement. Soldiers and commanders should be aware of the different influence of the loading exercises along the course on the AT and on the PT structure, as "reduced" tendons structure might put the soldiers at higher risk for injury in the future.

A Comparison between Different Types and Frequency of Physiotherapy Treatment for Children and Adolescents with Postural Problems and Low Back Pain.

AIM: To examine the effect of a once-a-week group physiotherapy session in addition to a once-a-month individual physiotherapy treatment, in comparison to a monthly individual physiotherapy treatment. METHODS: Fifty children and adolescents aged 10-18 years with poor back posture, some of whom had LBP, met individually with a physiotherapist once a month. The intervention group received an additional once-a-week group physiotherapy session for 12 weeks. Thorax curve angle, postural behavior, and low back pain (LBP) were measured before and after intervention. RESULTS: The thorax curve angle decreased from 39.2 ± 9.3 to 28.2 ± 6.8 (p < 0.001) in the group + individual therapy group and from 38.9 ± 9.3 to 27.9 ± 7.8 in the individual therapy only group (p < 0.001). LBP decreased from 5.6 ± 2.2 to 1.6 ± 1.9 (p < 0.001) and from 5.5 ± 2.1 to 2.8 ± 2.0 (p < 0.001). A significantly greater improvement in postural behavior was found in the group + individual therapy group (p = 0.04). Moreover, attrition rates were lower in the experimental group. CONCLUSION: A lower-frequency individual physiotherapy treatment for 12 weeks proved as beneficial as the same program with an additional higher-frequency group physiotherapy in improving thorax curve angle and LBP. However, the higher-frequency group physiotherapy in addition to the lower-frequency individual treatment was significantly more effective in improving postural behavior and adherence to treatment.

Achilles and patellar tendon structure following a prevention program in male combat soldiers.

OBJECTIVES: The aims of the study were to compare the prevalence of soldiers with musculoskeletal symptoms between soldiers that participated in a prevention program (INT) and a control group (CONT); and, to assess whether 'high risk' for a symptom indicator [participants with patellar tendon (PT) echo-type III+IV >10% or Achilles tendon (AT) echo-type III >8.5%] applies when a prevention intervention is used. METHODS: Soldiers from two consecutive infantry commanders courses (year 1-CONT, n = 165; year 2-INT, n = 196) were examined pre-course for AT and PT structure using ultrasound tissue characterization (UTC), and their musculoskeletal overuse symptoms were assessed and recorded by military physicians throughout the course. A prevention program was provided to the INT group (year 2) during the 14-week course. RESULTS: No significant differences were found in the prevalence of soldiers with symptoms between the two groups [INT: 39 (19.9%), CONT: 40 (24.2%); p = .32]. Using the indicator at baseline, 20 soldiers (10.2%) were suggested to be at 'high risk.' Of those 20 soldiers, 17 actually had symptoms during the course (positive predictive value-85%). The prevalence of soldiers with a suggested 'high risk' according to our indicator who had no symptoms during the course was low (3/20, 15%). Twenty-two soldiers who had symptoms during the course had not been suggested to be at 'high risk' by our indicator. CONCLUSION: Our intervention did not reduce the prevalence of soldiers with symptoms. Our 'high risk' pre-course, AT and PT structure indicator is valid and can be used as a screening tool to reduce the prevalence of symptoms in combat soldiers; with the caution that soldiers that were not identified by the indicator, might also have symptoms along the course.

Physical activity, resilience, emotions, moods, and weight control, during the COVID-19 global crisis.

OBJECTIVES: This study aimed at exploring the relationships between physical activity, weight control, and psycho-social aspects of the COVID-19 lockdown, which have characterized the Israeli population's behavior during the COVID-19 global crisis. DESIGN: Cross-sectional survey research. METHODS: Participants included 1855 men and women aged 18 and above, from different regions in the country and representing different sectors. They were recruited through the social media in a "snowball" sampling, and filled out a self-administered six-part survey: Demographic background, the International Physical Activity Questionnaire (IPAQ), the positive and negative affect scales (PANAS), the Conor and Davidson resilience scale, a questionnaire for measuring depressive symptoms, and questions regarding weight change based on the Israeli National Health and Nutrition (MABAT) survey. RESULTS: Routine physical activity (PA) was reported by 76.3% of the participants before the lockdown, 19.3% stopped exercising during this period, and 9.3% began exercising during the lockdown. The participants who were physically active during the lockdown period reported a higher level of resilience and positive feelings, and a lower level of depression, compared with those who were not physically active. People who were physically active during the lockdown maintained their weight compared with those who were inactive. Concerning weight change, 44.8% of the respondents maintained their weight, and a higher percentage of people reported weight gain than those who reported weight loss. CONCLUSIONS: Continuous PA before and during the COVID-19 lockdown were associated with higher resilience and positive emotions, and depressive symptoms, in people aged 18 and above. Although a causal link cannot be established, in light of the results of the present study, encouraging physical activity may contribute to improving mental health and a sense of self-efficacy, as well as to maintaining weight during a crisis.

Physical activity, resilience, emotions, moods, and weight control of older adults during the COVID-19 global crisis.

BACKGROUND: The main purpose of the research was to examine the differences between adults in the age group 70+ and two other age groups (45-59 and 60-69), concerning their healthy and active lifestyle. The death toll of the current COVID-19 pandemic is strongly biased toward the elderly. However, some studies of crises suggest that older adults tend to perceive events as less stressful than do younger people. Therefore, we examined healthy behavior in populations at risk according to the age cutoff-points used by the Ministry of Health at the time of vaccination, and divided the participants into three age groups (45-59, 60-69, and 70+) following health organizations' recommendations. METHODS: Participants were 1202 people, 381 males and 821 females, aged 45-90. A survey comprised of six parts was used: Demographic background, the International Physical Activity Questionnaire-short version, Positive and Negative Affect Schedule - PANAS, the Connor and Davidson Resilience Scale, a questionnaire for measuring depressive moods, and questions regarding weight change, based on the Israeli National Health and Nutrition (MABAT) survey. Data were collected in Israel during the first complete lockdown. The questionnaire was distributed via e-mail, WhatsApp, Twitter, and Facebook using a snowball sampling method. RESULTS: Resilience and negative feelings and depression symptoms were higher in age group 45-59 compared to 70+ year-old participants, and the depression symptoms score was also higher among participants aged 45-59 compared to ages 60-69. Physical activity was associated with higher resilience, fewer depression symptoms, and fewer negative emotions. Regarding gender and psychological variables, no differences were found. During the time of lockdown, weight change was not prevalent and sleeping hours increased. CONCLUSION: In adults at 70+, the physical activity level, physical activity before and during the lockdown, emotions, sleeping hours, and weight change were similar to the other adult groups that were examined (45-59 and 60-69). However, in the older adults groups (70+ and 60-69), resilience and depression symptoms were lower than in the youngest age group.

Weight change adjusted equations for assessing resting metabolic rate in overweight and obese adults.

BACKGROUND: Although over one hundred equations have been developed to predict the energy expenditure of individuals, none are sensitive to weight change in assessment of resting metabolic rate (RMR) before and after weight loss. OBJECTIVE: To formulate adjusted equations for overweight and obese individuals and to compare their accuracy with existing prediction RMR equations before and after weight loss. SUBJECTS/MATERIALS: This is historical prospective study. Participants included 39 overweight and obese men and women before and after losing 10-20% from baseline weight on a diet and physical activity regimen for at least three months. Pre and post weight loss measured RMR results were compared to estimated RMR using several existing prediction equations: Harris and Benedict, Ravussin and Bogardus, and Mifflin et al. To improve the accuracy of these prediction equations, we suggest new equations adjusted for weight loss, based on measured RMR and evaluated their accuracy. RESULTS: Pre and post weight loss data indicated: significant fat reduction in both genders; reduction in free-fat mass only in men, and a significant decrease in measured RMR only in women. Our suggested equations were the most accurate and closest to measured RMR in both genders, in comparison to the Harris and Benedict, Ravussin and Bogardus, and Mifflin et al equation results. Estimated RMR using the latter equations was significantly lower than measured RMR in both genders at pre and post weight loss (P < 0.01). CONCLUSIONS: This study highlights the need for adjusting RMR equations before and after weight loss in overweight and obese individuals. Further research is needed to validate our suggested equations.

Generalized joint hypermobility, scoliosis, patellofemoral pain, and physical abilities in young dancers.

BACKGROUND: Many young girls with generalized joint hypermobility (GJH) choose to participate in dance because their bodies are suited for this activity. Scoliosis tends to occur often in thin girls, who also are more likely to choose dance. Both anomalies (GJH and scoliosis) may be related to reduced abilities such as diminished strength and insufficient postural balance, with increased risk for musculoskeletal conditions. The main objectives of the present study were to determine the prevalence of dancers with GJH, the prevalence of dancers with scoliosis, and the prevalence of dancers with these two anomalies; and, to determine differences in physical abilities and the presence of patellofemoral pain (PFP) between young female dancers with and without such anomalies. METHODS: One hundred thirty-two female dancers, aged 12-14 years, were assessed for anthropometric parameters, GJH, scoliosis, knee muscle strength, postural balance, proprioception ability, and PFP. RESULTS: GJH was identified in 54 dancers (40.9%) and scoliosis in 38 dancers (28.8%). Significant differences were found in the proportion of dancers with no anomalies (74 dancers, 56.1%) and dancers with both anomalies (34 dancers, 25.8%) (p < .001). Dancers with both anomalies had reduced dynamic postural balance in the anterior direction (p = .023), reduced proprioception ability (p < .001), and weaker knee extensors (p = .036) and flexors (p = .040) compared with dancers with no anomalies. Among dancers with both anomalies, 73.5% suffered bilateral PFP, 17.6% suffered unilateral PFP, and 8.8% had no PFP (p < .001). CONCLUSIONS: A high prevalence of young girls participating in dance classes had GJH, as the increased joint flexibility probably provides them with some esthetic advantages. The high prevalence of scoliosis found in these young dancers might be attributed to their relatively low body mass, their delayed maturation, and the selection process of dancers. Dancers with both GJH and scoliosis had decreased muscle strength, reduced postural balance, reduced proprioception, with higher risk of PFP. The main clinical implications are the need to reduce the risk of PFP among dancers by developing appropriate strength and stabilizing exercises combined with proprioceptive and postural balance training, to improve the correct alignment of the hyperextended and hypermobile joints, and to improve their supporting muscle strength.

Can Achilles and patellar tendon structures predict musculoskeletal injuries in combat soldiers?

Aiming to investigate whether Achilles tendon (AT) structure and patellar tendon (PT) structure are risk factors for musculoskeletal injuries in combat soldiers, 168 participants were recruited from an infantry commander's course. The AT and PT were examined pre-course using UTC to capture the structure of four echo-type fibers (I-IV). All injuries were assessed by military physicians pre-course and throughout the 14-week course. Soldiers who were injured during the course had a significantly higher pre-course prevalence of AT and PT echo-type III and echo-type IV compared to soldiers that were not injured during the course. Variables that were found to be associated with injured/non-injured participants were echo-type III + IV of the PT (OR = 1.44, 95% CI = 1.24-1.68) and echo-type III of the AT (OR = 1.69, 95% CI = 1.35-2.12). ROC analyses showed that the best model, exhibiting both high sensitivity and low specificity, was that participants with PT echo-type III + IV > 10% or AT echo-type III >8.5% had the highest risk of being injured during the course. In conclusions, the tendon structure at the beginning of high-intensity activity or physical training program might be a risk factor for subsequent injury during the course. Soldiers and high-level athletes should be aware of the cutoff points for fiber types in tendon structure that might put them at high risk for future injury. At-risk soldiers/athletes should be provided with an intervention program before they start their training program, with the aim of improving the tendon structure and preventing subsequent injury.

Ultrasound Tissue Characterization (UTC) of the Achilles Tendon in Pre- and Post-Pubertal Dancers.

This study examined whether maturation status, body physique, and the impact of training are related to the development of Achilles tendon structure in young dancers. Seventy-one pre- and post-menarche dancers (12 to 15 years of age) were recruited. The Achilles tendon of each dancer was examined via ultrasonography tissue characterization (UTC) imaging. The cross-sectional area (CSA) and the fibrillar structure (echo types I to IV) were measured. The participants were screened for anthropometric parameters (weight, height, and leg length) with body mass index (BMI) and BMI percentile calculated; for hours and impact of training; for Tanner pubertal maturation; and for pain in their Achilles tendon (VAS scale). In addition, age and age at onset of menarche were documented. Tendon structure was found to differ between pre- and post-menarche dancers. Post-menarche dancers had a significantly lower percentage of echo type I fibers and a significantly higher percentage of echo type II, III, and IV fibers, with a greater CSA compared to pre-menarche dancers. The tendon structure was found to be correlated with BMI percentile, but no correlations were found with chronologic age or the impact of dance training. Furthermore, ANCOVA showed that BMI had a statistically significant effect on fiber types II and III (p < 0.005) and that the effect of menarche was significant, meaning that pre-menarche dancers had a lower BMI compared with those who were post-menarche. It is concluded that pre- and post-menarche dancers had developed different patterns of Achilles tendon fiber structure. Body mass index was found to be the most significant factor influencing the different tendon structures in young pubertal dancers.

The influence of a multidisciplinary intervention program on Achilles tendon structure in children with overweight and obesity.

The effects of childhood obesity on tendon structure and its relation to physical activity are barely known. We aimed to investigate the influence of a 6-month multidisciplinary childhood obesity management program (which included dietary intervention and an exercise program) on Achilles tendon structure in overweight/obese children. Twenty-five overweight/obese children (overweight group) who participated in a 6-month multidisciplinary childhood obesity program, and 27 normal-weight controls were examined for anthropometric measurements and for Achilles tendon structure (using ultrasound tissue characterization to capture a three-dimensional structure of four echo type fibers and the cross-sectional area) at baseline, 3, and 6 months. The BMI of the overweight group significantly decreased from the pre- to the post-intervention period, (p = .002, η2 = .229), yet among the control group, the BMI significantly increased (p = .002, η2 = .222). Interactions (pre-post × group) showed a significant decrease in the prevalence of echo type I and in echo type III fibers and a significant increase in the prevalence of echo type II fibers and in the cross-sectional area along the intervention. No significant changes in echo type fibers were found in the control group along the 6 months.Conclusion: At pre-intervention, the overweight group had significantly "worse" tendon structure, with a lower prevalence of echo type II fiber and a higher prevalence of echo type III fibers compared with the control group. Following the 6-month intervention, the tendon structure of the overweight group was "positively" changed, with reduced echo type III fibers and increased echo type II fibers. What is Known: • Physical activity and weight reduction programs are efficient for obese children. • Obese children tend to suffer orthopedic problems and pain during physical activity. What is New: • Pre-intervention, obese children had 'worse' tendon structure compared to controls. • Following 6-month program, tendon structure of obese children 'positively' changed.

Unilateral and bilateral patellofemoral pain in young female dancers: Associated factors.

Aiming to evaluate the prevalence of unilateral/bilateral patellofemoral pain (PFP) among young dancers, and to investigate whether different factors are associated with PFP in young dancers, 132 dancers aged 12-14 years were assessed for PFP. Anthropometric parameters, proprioception ability, dynamic postural balance (DPB), and muscle strength were measured. PFP was found in 64.1% of the dancers. No significant differences in the prevalence of dancers with no, unilateral, or bilateral PFP at different ages were found. Significant age effects were found for anthropometric and developmental measurements, and for intensity of training. PFP effect was found for DPB asymmetry, ankle proprioception, and leg-length %height. A higher hip abductor/adductor ratio was associated with PFP in 14-year-old dancers. Binomial logistic regression showed that increased number of hours per day (h/day) and decreased number of hours per week (h/week), low proprioception scores, greater leg length as %height, and more anterior DPB asymmetry were significant predictors of PFP. In conclusion: unilateral/bilateral PFP is common among young dancers. Body morphology, reduced ankle proprioception ability, DPB asymmetry, and increased h/day of practice are associated with PFP. Dance teachers should start monitoring the impact of training and implement injury modification/prevention strategies when their students are at a young age.

Correlates of Early-Stage Frailty-Sleep, Fitness, Oxidative Stress, and BMI.

Frailty reflects a decreased reserve in multiple systems resulting from cumulative decline. Frailty markers should be identified as early as possible to attenuate the loss of reserve. The aim of this study was to identify potentially modifiable correlates of frailty in relatively healthy older adults. Volunteers (n = 122) were recruited from local councils and, based on gender and age, were divided into one group of men aged 77.0 (±5.3), and two groups of women, aged 68.8 (±3.6) and aged 78.4 (±3.4). Frailty was assessed by a Frailty Index. The examined correlates were: physical activity, physical fitness (predicted peak VO2), sleep quality, oxidative stress (hydrogen peroxide-H2O2) and depression. Both groups of women had poor scores on physical fitness compared to women's norms. In order to examine the contribution of each of the potential correlates to explaining the variance of frailty, stepwise regressions were performed for each group separately. Based on the results, none of the suggested correlates significantly explained the variability of frailty in the men. In the younger-aged women, predicted peak VO2 and sleep quality explained 22.4% of the variability of frailty. In the older women, Body Mass Index (BMI), oxidative stress and sleep quality explained 34.9% of the variance. It is possible that increased aerobic fitness and interventions for improving sleep quality in older, seemingly healthy women will slow down the frailty process. Further research is needed to assess potential correlates of frailty, and to initiate suitable interventions to mitigate the signs of frailty at an early stage.