Association between muscle strength and depression in a cohort of young adults.

BACKGROUND: The study investigated the association between knee joint muscle strength and the prevalence of depression in a cohort of young adults. METHODS: The observational, population-based study was performed with 909 participants (29.02 ± 2.03 years; 48.73% male) from the Central European Longitudinal Studies of Parents and Children: Young Adults (CELSPAC: YA), who were retained to analysis. Quadriceps and hamstring knee muscle strength were assessed by isokinetic dynamometry, and depression by Beck's Depression Inventory (BDI-II). Statistical comparisons (Mann-Whitney and Chi-squared test) and effect size analyses (Eta-Squared, and Odds Ratio) were conducted. RESULTS: The main findings revealed an inverse association between knee joint muscle strength and depression, with individuals who had low muscle strength having 3.15 (95% CI = 2.74-3.62) times higher odds of experiencing depression. Specifically, participants with low extensor strength had 4.63 (95% CI = 2.20-9.74) times higher odds, and those with low flexor strength had 2.68 (95% CI = 1.47-4.89) times higher odds of experiencing depression compared to those individuals with high muscle strength. Furthermore, gender-specific analyses revealed that males with low muscle strength had 2.51 (95% CI = 1.53-4.14) times higher odds, while females had 3.46 (95% CI = 2.93-4.08) times higher odds of experiencing depression compared to individuals with high muscle strength. CONCLUSIONS: Strong knee muscles seems to be a key factor in preventing depression, specially in female young adults. The results support the importance of promoting an increase in muscle strength through physical activity as a preventive strategy against depression in this population.

Does muscular fitness predict cardiorespiratory fitness in adolescent girls? A 3-year follow-up study.

The main purpose of the study was to establish, whether future cardiorespiratory fitness might be predicted by the level of muscular fitness at baseline. In this 3-year follow-up study, we recruited 240 secondary school girls at the age of 15 y, who were followed until the age of 17 y. Muscular fitness included the following tests: (i) standing broad jump (cm), (ii) sit-ups in 60 s (#) and (iii) squats in 60 s (#). Cardiorespiratory fitness was split into aerobic endurance (the 800-m run test) and speed endurance (the 400-m run test). Better performances in the 800-m run and the 400-m run tests at follow-up were correlated with higher levels of standing broad jump, sit-ups and squats in 60 s measured at baseline. In regression models adjusted for fat mass and maturity offset, standing broad jump, sit-ups and squats in 60 s were positively associated with the 800-m run test, while only standing broad jump remained significantly and positively associated with the 400-m run test. These data suggest that interventions enhancing muscular fitness should be recommended, as the effects are likely to be associated with future cardiorespiratory fitness in adolescent girls.

Effects of Load Carriage on Postural Sway and Relative Ground Reaction Forces in Special Police Officers: A Cross-Sectional Study.

Although excessive load carriage results in biomechanical gait changes, little evidence has been provided regarding its impact on postural sway. Therefore, the main purpose of this study was to determine whether heavier loads have effects on changing foot stability and postural sway in special police officers. Thirty male special police officers (age = 40 ± 6 years, height = 180 ± 5 cm, weight = 89 ± 8 kg) were assessed in four conditions: (1) carrying no load, (2) carrying a 5 kg load, (3) carrying a 25 kg load, and (4) carrying a 45 kg load. Foot characteristics during standing were assessed with Zebris pedobarographic pressure platform. Heavier loads increased the center of pressure (COP) path length and average velocity, length of minor and major axis, and 95% confidence ellipse area, while a decrease in angle between Y and major axis was observed. Relative forces beneath the left forefoot and right backfoot regions decreased and an increase in relative forces beneath the left backfoot and right forefoot was observed. When carrying heavy loads, static foot parameters rapidly changed, especially in COP path length and average velocity.

Spatio-Temporal Gait Parameters in Association with Medications and Risk of Falls in the Elderly.

Purpose: The aim of this study was to analyze factors affecting spatio-temporal gait parameters in elderly people of both genders and different ages with different risks of fall, fall history, and medications. Patients and Methods: A total of 210 community-dwelling older adults (156 females, 54 males; mean age 72.84±6.26 years) participated in this study. To assess the risk of falls, the Downton Fall Risk Index was used. An additional question about medication intake (all prescribed drugs) was asked. To assess the spatio-temporal gait parameters, the Zebris FDM platform was used. Gait parameters and Downton Fall Risk Index, stratified by participants' history of falls, multiple medication use (0/1/2+), gender, age, and medication categories, were statistically analyzed using the Mann-Whitney U-test and Kruskal-Wallis test. Results: When comparing different medication categories, a Downton Fall Risk Index score indicating a high risk of falls was observed in the psychotropic medication category (3.56±1.67). A gait velocity suggesting a higher risk of falls (≤3.60 km/h) was observed in the psychotropic (2.85±1.09 km/h) and diabetes (2.80±0.81 km/h) medication categories, in the age groups 70-79 years (3.30±0.89 km/h) and 80+ years (2.67±0.88 km/h), and in participants using two or more medications (3.04±0.93 km/h). Conclusion: The results of this study confirm previous observations and show that higher age and multiple medication negatively affect the gait, and that the higher risk of falls is associated with psychotropic and diabetes medication use. These results provide important information for future fall preventive programs for the elderly that would be especially beneficial for elderly people taking psychotropic and diabetes medication.

Associations between Fat Mass and Fat Free Mass with Physical Fitness in Adolescent Girls: A 3-Year Longitudinal Study.

The main purpose of the study was to examine the longitudinal associations between fat mass and fat free mass with health-related physical fitness. Two-hundred and forty 15-year old adolescent girls were measured at the baseline and after a period of 3 years (17 years). Health-related physical fitness included the following tests: (1) explosive power of the lower extremities (standing broad jump); (2) muscle endurance of the trunk (sit-ups in 60 s); (3) flexibility (sit-and-reach test); (4) muscle endurance of the lower extremities (squats in 60 s); (5) aerobic endurance (the 800 m run test); and (6) speed endurance (the 400 m running test). Fat mass and fat free mass were assessed using the bioelectrical impedance method. Longitudinal associations were analyzed with linear mixed model estimates. After adjusting for body mass index, fat mass was negatively associated with standing broad jump (ß = −1.13, p < 0.001), sit-ups in 60 s (ß = −0.27, p < 0.001), and squats in 60 s (ß = −0.27, p < 0001), while positive associations with the 800 m running test (ß = 0.02, p < 0.001) and the 400 m running test (ß = 0.02, p < 0.001) were observed. On the other hand, fat free mass was positively associated with standing broad jump (ß = 1.14, p < 0.001), sit-ups in 60 s (ß = 0.28, p < 0.001), and squats in 60 s (ß = 0.28, p < 0001), while the 800 m running test (ß = −0.02, p < 0.001) and the 400 m running test (ß = −0.02, p < 0.001) exhibited negative associations. This study shows that fat mass and fat free mass components are longitudinally, but oppositely associated with health-related physical fitness in adolescent girls.

Tracking of health-related physical fitness in adolescent girls: a 3-year follow-up study.

BACKGROUND: Evidence has shown that higher levels of physical fitness (PF) in youth have beneficial effects on adult health-related outcomes. However, the tracking of separate PF components during adolescence has been less studied. Since PF often starts to rapidly decline during adolescence, it is necessary to provide information regarding critical time-point for interventions. This study aimed to analyze the extent of tracking the components of PF through PF tests. METHODS: In this longitudinal study, we recruited 240 adolescent girls with recoded data at 2 time-points (15 y and 17 y). PF included body composition (fat mass), explosive power of lower extremities (standing broad jump), muscle endurance of the trunk (sit-ups in 60 s), flexibility (sit-and-reach test), muscle endurance of lower extremities (squats in 60 s), aerobic endurance (the 800 m run test) and speed endurance (the 400 m run test). Tracking coefficients were calculated using generalized estimating equations. Tertiles (high, moderate and low) were calculated for each fitness component. RESULTS: The highest tracking coefficients between the two time-points were found for explosive power of lower extremities (ß = 0.98), followed by flexibility (ß = 0.89), body composition (ß = 0.88), speed endurance (ß = 0.86), aerobic endurance (ß = 0.75), muscle endurance of lower extremities (ß = 0.65), and muscle endurance of the trunk (ß = 0.51). Tertile ratings remained stable across the two time-points. CONCLUSIONS: Moderate to high tracking of PF in adolescent girls suggests that interventions aiming to increase the level of PF should probably begin in early adolescence.

Normative Data for Musculoskeletal Fitness in 13,217 Children and Adolescents: The Croatian Fitness (CROFIT) Study.

Purpose: The main purpose of the study was to establish normative data for health-related musculoskeletal fitness. Method: We recruited 13,217 children and adolescents aged 11-18 years (6,181 boys and 7,036 girls; 57% of girls). To evaluate musculoskeletal fitness, the following field tests were applied: standing broad jump (cm), sprint 20 m (sec), medicine-ball throw (dm), sit-ups in one minute (#), sit-ups in one minute (short, #), and squats in one minute (#). Curves for the 10th, 20th, 30th, 40th, 50th (median), 60th, 70th, 80th, and 90th percentiles were calculated using the Lambda (L), Mu (M), and Sigma (S) method. The LMS method assumes that the data can be normalized by using a power transformation and removing the skewness. Results: Median scores for standing broad jump, sprint 20 m, medicine-ball throw, sit-ups in one minute, sit-ups in one minute (short) and squats in one minute were 185.00 cm, 3.66 sec, 80.00 dm, 46.00 x, 56.00 x and 49 x in boys and 160.00 cm, 4.01 sec, 60.00 dm, 40.00 x, 49.00 and 43 x in girls. Effect sizes (ES) showed that boys performed better in all physical fitness tests (ES = 0.50-1.05), compared to girls. In general, age-related physical fitness changes showed the plateau between ages 15 and 16 in boys, while in girls, the plateau was reached at the age of 14. Conclusions: This study shows standards for musculoskeletal tests in youth.

Changes in plantar pressure, contact area and contact time symmetry during the gait 4 weeks before and 12 and 24 weeks after unilateral total hip arthroplasty.

BACKGROUND: Foot to ground pressure changes in total hip arthroplasty patients' gait are not widely described, although they are sensitive to gait abnormalities and the distribution of plantar pressures may differ before and after the surgery. This study aimed to analyse longitudinally differences in plantar pressure during gait in total hip arthroplasty patients compared to healthy controls. METHODS: Eighteen males participated in this study. Eight males, who underwent unilateral total hip arthroplasty, participated at the data collection three times: 4 weeks before the surgery, 12 and 24 weeks after, and ten healthy controls. All participants were asked to walk over Emed platform. To compare differences between the affected and unaffected limbs, Kolmogorov-Smirnov test was used. Kruskal-Wallis test was used to compare the difference between total hip arthroplasty patients and healthy controls. FINDINGS: Statistically significant differences between the affected and unaffected limb were observed only during the preoperative measurement in peak pressure at MH4 area and in the contact area at MH4 and big toe. When comparing total hip arthroplasty patients and controls, a difference in the contact time at MH2, MH3 and MH4 areas 12 weeks after surgery and at MH2 and MH4 24 weeks after the surgery were observed. INTERPRETATION: The shorter contact time at forefoot areas may indicate an alteration in the propulsive phase of the gait of both the affected limb and unaffected limb in total hip arthroplasty patients as a result of decreased terminal hip extension during the stance phase described in previous studies.