Lower Extremity Muscular Strength Research Articles

High-intensity interval training and thromboembolic events during chemotherapy for testicular cancer: a retrospective analysis from the Body & Cancer cohort

Background: Men with testicular cancer receiving platinum-based chemotherapy have an increased risk of thromboembolic events, with incidence rates between 8–24%. A recent trial evaluating the effect of high-intensity interval training (HIIT) prematurely closed as three out of nine participants (33%) in the intervention group developed a thromboembolic event. The purpose of this retrospective cohort study was: 1) (primary) to evaluate the incidence of thromboembolic events in men receiving chemotherapy for testicular cancer who had participated in HIIT during a 6-week exercise program (Body & Cancer) 2) to describe the feasibility of this program. Material and methods: Forty men who had participated in at least one HIIT session from February 2007 to February 2020 were included. Electronic medical records were searched for incident thromboembolic events (arterial and venous) during Body & Cancer and up to one-year post-chemotherapy. Attendance, cardiorespiratory fitness (VO2-peak), and upper and lower extremity muscular strength (1 repetition maximum (RM)) were obtained from the Body & Cancer database. Results: One participant developed a thromboembolic event during Body & Cancer. No participants developed a thromboembolic event in the follow-up period. In all, data represent 160 HIIT sessions with a median attendance of eight sessions [range 1–19]. Statistically significant increases in upper and lower extremity strength were observed (8.6 (4.2 to 13.0) and 26.0 (14.9 to 37.0) kg, respectively). No significant increase in cardiorespiratory fitness was found (0.14 (−0.03 to 0.31) l/min). Conclusion: While conclusions on the safety of HIIT cannot be drawn, data from the present study do not support previous findings cautioning avoidance of HIIT due to a possible added risk of thromboembolic events in men receiving platinum-based chemotherapy for testicular cancer. Considering the potential for positive effects on cardiovascular outcomes associated with HIIT, future studies with robust design should be performed in this population to confirm these observations.

Association between muscle strength and mass and bone mineral density in the US general population: data from NHANES 1999–2002

PurposeIt is known that muscle strength and muscle mass play a crucial role in maintaining bone mineral density (BMD). Despite this, there are uncertainties about how muscle mass, lower extremity muscular strength, and BMD are related. We examined the impact of lower extremity muscle strength and mass on BMD in the general American population using cross-sectional analysis.MethodsIn the study, we extracted 2165 individuals from the National Health and Nutrition Examination Survey 1999–2002. Multivariate logistic regression models were used to examine the association between muscle strength, muscle mass, and BMD. Fitted smoothing curves and generalized additive models were also performed. To ensure data stability and avoid confounding factors, subgroup analysis was also conducted on gender and race/ethnicity.ResultsAfter full adjustment for potential confounders, significant positive associations were detected between peak force (PF) [0.167 (0.084, 0.249) P < 0.001], appendicular skeletal muscle index (ASMI) [0.029 (0.022, 0.036) P < 0.001], and lumbar spine BMD. A positive correlation was also found between PF, ASMI, and pelvis and total BMD. Following stratification by gender and race/ethnicity, our analyses illustrated a significant correlation between PF and lumbar spine BMD in both men [0.232 (0.130, 0.333) P < 0.001] and women [0.281 (0.142, 0.420) P < 0.001]. This was also seen in non-Hispanic white [0.178 (0.068, 0.288) P = 0.002], but not in non-Hispanic black, Mexican American and other race–ethnicity. Additionally, there was a positive link between ASMI and BMD in both genders in non-Hispanic whites, and non-Hispanic blacks, but not in any other racial group.ConclusionPF and ASMI were positively associated with BMD in American adults. In the future, the findings reported here may have profound implications for public health in terms of osteopenia and osteoporosis prevention, early diagnosis, and treatment.

Research progress on analgesic effect of adductor canal block after knee arthroplasty

To summarize the research progress of the analgesic effect of adductor canal block (ACB) applied to knee arthroplasty, in order to find the ACB mode that can obtain better effectiveness. The research progress of the analgesic effect of ACB after knee arthroplasty was reviewed by widely consulting the related literature on ACB at home and abroad in recent years. In recent years, multimodal analgesia has become the mainstay of postoperative pain management after knee arthroplasty. Among these, ACB replaces the once "gold standard" femoral nerve block (FNB) by offering comparable and effective analgesia with better preservation of quadriceps function. It is generally safe and efficient to use 0.2% ropivacaine ACB with initial loading doses of 15-30 mL and continual loading doses of less than 8 mL/hour to give analgesia comparable to FNB with minimal impact on lower extremity muscular strength. However, the risk of patient falls must still be taken into consideration by medical staff. Adjuvants like dexmedetomidine and dexamethasone used in ACB can increase the analgesic duration and postoperative analgesic impact. As a perineural adjunct for ACB, 1 µg/kg dexmedetomidine may strike a balance between safety and analgesic efficacy. ACB is a safe and effective analgesia method after knee arthroplasty. The adductor canal anatomy, the optimum blocking strategy and blocking site of ACB are all hotly debated and still require additional study due to the significant variety of the nerve structures in adductor canal.

Power, Strength, And Physical Function: A Prospective Study Examining All-cause Mortality

Functional capacity has traditionally been the primary fitness characteristic studied when examining mortality. With the advent of a variety of muscle strengthening protocols becoming more popular since the turn of the century, the potential role of muscular strength and physical function is now being examined in respect to mortality. PURPOSE: Examine the associations between lower extremity muscular power, muscular strength, physical function and all-cause mortality in a nationally representative sample over U.S adults. METHODS: The study sample (2,631) included participants (≥50 years of age) from the 1999-2002 National Health and Nutrition Examination Survey. The primary independent variables in this study included: time to peak force in seconds (TPFs); peak force in newtons (strength)(PF-N); time to complete a 20-foot walk in seconds(TTCWs). Weighted quartiles (Q) of TPFs, PF-N, and TTCWs were created. The primary dependent variable in this study was all-cause mortality. Cox-proportional hazard models were used for all analyses, adjusting for age, gender, race-ethnicity, education, self-reported smoking, cardiovascular disease, stroke, chronic obstructive pulmonary disease, hypertension, self-reported diabetes, and waist circumference. Quartile 1 (Q1) served as the referent group for analysis with PF-N. Quartile 4 (Q4) served as the reference groups for analyses with TPFs and TTCWs. RESULTS: A dose-response relationship was found for quartiles of increasing PF-N ([Q2: 0.59, 95% CI 0.52-0.68], [Q3: HR 0.48, 95% CI 0.37-0.60], and [Q4: HR 0.32, 95% CI 0.23-0.46]) and decreasing TTCWs ([Q3: HR 0.64, 95% CI 0.53-0.76]), [Q2: HR 0.58, 95% CI 0.46-0.74], [Q1: 0.35, 95% CI 0.26-0.47]). No significant associations were found for TPFs. CONCLUSIONS:Greater PF-N and lower TTCWs time were associated with significantly lower risk for all-cause mortality. Future research should examine the role of upper and lower extremity muscular strength and physical function in predicting all-cause and disease specific mortality.

Association of Skeletal Muscle Strength and Body Fat Distribution on Pulmonary Functions

Objectives: The body's muscle strength and fat distribution are essential for a normal, healthy life. This study aimed to assess a link between pulmonary function tests, upper and lower extremity muscular strength, and body fat distribution in Saudi males. Methodology: This cross-sectional study was conducted in the department of physiology at the College of Medicine, King Saud University, Riyadh, Saudi Arabia. A total of 106 participants were invited, ranging from 20-47 years old. The participants were divided into three groups, with ages ranging from 20-29 years old, 30-39 years old, and 40–47 years old. The handgrip and thigh muscle strength was assessed using isometric dynamometry. Pulmonary function tests were performed according to the American Thoracic Society's guidelines and recommendations. Results: There was no significant difference between the three age groups in upper and lower limb muscle strength. The handgrip strength was stable from 20 to 47 years, ranging from 37 to 39. The thigh muscle strength was not affected by age among the three age groups. Skinfold measurement of the upper body showed no significant differences in biceps and triceps. However, skinfold measurements of subscapular and supra iliac were different significantly. Conclusion: There was no association between the age groups in upper and lower limbs muscle strength. It’s suggested that further large studies will be conducted to explore the findings and reach better conclusions.

Association of Skeletal Muscle Strength and Body Fat Distribution on Pulmonary Functions

Objectives: The body's muscle strength and fat distribution are essential for a normal, healthy life. This study aimed to assess a link between pulmonary function tests, upper and lower extremity muscular strength, and body fat distribution in Saudi males. Methodology: This cross-sectional study was conducted in the department of physiology at the College of Medicine, King Saud University, Riyadh, Saudi Arabia. A total of 106 participants were invited, ranging from 20-47 years old. The participants were divided into three groups, with ages ranging from 20-29 years old, 30-39 years old, and 40–47 years old. The handgrip and thigh muscle strength was assessed using isometric dynamometry. Pulmonary function tests were performed according to the American Thoracic Society's guidelines and recommendations. Results: There was no significant difference between the three age groups in upper and lower limb muscle strength. The handgrip strength was stable from 20 to 47 years, ranging from 37 to 39. The thigh muscle strength was not affected by age among the three age groups. Skinfold measurement of the upper body showed no significant differences in biceps and triceps. However, skinfold measurements of subscapular and supra iliac were different significantly. Conclusion: There was no association between the age groups in upper and lower limbs muscle strength. It’s suggested that further large studies will be conducted to explore the findings and reach better conclusions.

Effects of mental practice on mobility of individuals in the early subacute post-stroke phase: A randomized controlled clinical trial

IntroductionOnly a small number of clinical trials were designed to investigate Mental Practice (MP)'s use for gait rehabilitation in individuals in the early subacute post-stroke phase. This trial aims to investigate the effect of mental practice on mobility rehabilitation in the early subacute phase after a stroke in comparison to a control group. MethodsRandomized controlled clinical trial with 16 individuals diagnosed with a stroke between 50 and 80 years of age. Mobility was evaluated using Timed Up and Go and the Five-Minute Walk Test. In addition, lower extremity muscular strength, Timed Up and Go Assessment of Biomechanical Strategies, quality of life, and depression were evaluated. ResultsBefore and after intervention (within-subjects), mental practice group showed improved mobility in Timed Up and Go (p = 0.01,r = 0.59), muscular strength for bending the right hip (p = 0.04, r = 0.50), for right knee bending (p = 0.03,r = 0.53), and in biomechanical performance of Timed Up and Go Assessment of Biomechanical Strategies(p = 0.01,r = 0.63). Control group showed improvement in neither mobility nor in muscular strength after intervention. Comparing the scores between the groups after intervention (between-subjects), no differences were found for any of the study's outcomes. In the analysis of deltas (gains), it was observed that mental practice group volunteers had a reduction in Timed Up and Go (p = 0.27,r = 0.29) and an increase in total Timed Up and Go Assessment of Biomechanical Strategies scores (p = 0.14,r = 0.36). ConclusionMental Practice was not associated with mobility, muscular strength, mental health, and quality of life improvement for patients in the early subacute post-stroke phase as compared to a control group.

노인의 근력과 혈압의 상관성

This study sought to examine the correlation between the senior citizens’ muscular strength and blood pressure as a cross-sectional research design based on the national fitness of 100. The subjects involved 901 senior citizens aged 65 to 89, and as for the variables of muscular strength, the upper extremity muscular strength measurement method was performed, and the lower extremity muscular strength measurement method was performed by repeating sitting on a chair and standing up off the chair, while the systolic and diastolic parameters were set for the blood pressure variables. did. As for the data on the results measured for this study, the mean (M ) and the standard deviation (SD) of each question were calculated by using the SPSS/PC+ Win 21.0 Version. A simple correlation analysis was performed to validate the correlation between the muscular strength and blood pressure of this measured value, and all of the statistical significance levels were set to the level of p.5, respectively. As a result of the study, the upper extremity muscular strength and systolic blood pressure, upper extremity muscular strength and the diastolic blood pressure demonstrated such a clear and positive correlation, while the lower extremity muscular strength and systolic blood pressure demonstrated a clear and negative correlation and statistical significance, while the lower extremity muscular strength and diastolic blood pressure demonstrated a weak and negative correlation, respectively. As a result, it was verified that there is a correlation between the muscular strength and the blood pressure.

The influence of a simulated game on muscular strength in female high-school and collegiate softball pitchers

ABSTRACT Softball pitchers often pitch several games within a day and over consecutive days during a competitive season. High volumes of pitches thrown can decrease muscular strength, resulting in less proximal force generation and upper extremity compensation to maintain performance. Therefore, the purpose of this study was to assess upper and lower extremity muscular strength after pitching in a simulated game. Fourteen softball pitchers (17.9 ± 2.3 years, 166.4 ± 8.7 cm, 72.2 ± 12.6 kg) completed baseline isokinetic strength assessment for knee, hip, trunk and pitching elbow flexion and extension as well as trunk rotation. Seven days later, participants pitched a simulated game consisting of 105 fastballs prior to repeating all strength assessments. Changes in muscular strength were assessed using paired samples t-tests, with significance set a priori as p ≤ 0.05. Normalised (%BW) stride leg knee extension peak torque was significantly higher (p = 0.020) post-simulated game (75.1 ± 24.6%BW) as compared to baseline (64.0 ± 19.5%BW) and trunk flexion peak torque was significantly higher (p = 0.009) post-simulated game (84.8 ± 47.0%BW) as compared to baseline (63.5 ± 47.1%BW). This study showed an increase in knee extension and trunk flexion strength after an acute bout of pitching. The findings give insight into muscular changes following pitching which can assist in appropriate softball training and recovery.

The Beneficial Effects of Cognitive Walking Program on Improving Cognitive Function and Physical Fitness in Older Adults.

Exercise and cognitive training can improve the brain-related health of the elderly. We investigated the effects of a cognitive walking program (CWP) involving simultaneous performance of indoor walking and cognitive training on cognitive function and physical fitness compared to normal walking (NW) outdoors. Participants were grouped according to whether they performed regular exercise for at least 3 months prior to the participation in this study. Active participants were assigned to the CWP-active group (CWPAG). Sedentary participants were randomly assigned to the CWP (CWPSG) or NW group (NWSG). CWP and NW were performed for 60 min, 3 times a week, for 6 months. Cognitive function (attention, visuospatial function, memory, and frontal/executive function) and physical fitness (cardiorespiratory fitness, lower extremity muscular strength, and active balance ability) were measured at baseline, 3 months, and 6 months after the program onset. Cognitive function showed improvements over time in all three groups, especially in CWPAG. No clear difference was observed between CWPSG and NWSG. Improvements in all fitness measures were also observed in all three groups. These findings collectively indicate the beneficial effects of CWP, as well as NW, on improving cognitive function and physical fitness in older adults, especially those who are physically active.

Monitoring Neuromuscular Performance in Military Personnel.

A necessarily high standard for physical readiness in tactical environments is often accompanied by high incidences of injury due to overaccumulations of neuromuscular fatigue (NMF). To account for instances of overtraining stimulated by NMF, close monitoring of neuromuscular performance is warranted. Previously validated tests, such as the countermovement jump, are useful means for monitoring performance adaptations, resiliency to fatigue, and risk for injury. Performing such tests on force plates provides an understanding of the movement strategy used to obtain the resulting outcome (e.g., jump height). Further, force plates afford numerous objective tests that are valid and reliable for monitoring upper and lower extremity muscular strength and power (thus sensitive to NMF) with less fatiguing and safer methods than traditional one-repetition maximum assessments. Force plates provide numerous software and testing application options that can be applied to military’s training but, to be effective, requires the practitioners to have sufficient knowledge of their functions. Therefore, this review aims to explain the functions of force plate testing as well as current best practices for utilizing force plates in military settings and disseminate protocols for valid and reliable testing to collect key variables that translate to physical performance capacities.

Association Between Lower Extremity Muscular Strength And Functional Performance In Community-Dwelling Elderly

The combination of aging with reduced muscle mass and muscle strength results in a higher risk of falls, hospitalizations, dependence, poorer quality of life, and all-cause mortality. Our hypothesis, in the present study, is that the elderly who present higher values in gait speed, as well as lower values in the Time Up and Go test, will have higher values of lower limb muscle strength. PURPOSE: To correlate functional capacity of walking and time up and go tests with the maximal isometric lower limb strength test in community-dwelling elderly. METHODS: Thirty-two elderly (2 men; age: 72 ± 9,2 yrs; body mass: 66 ± 10,6 kg; height: 152,27 ± 7,79 cm) who attended the Centro de Convivência do Idoso located in Paranoá, Brasília, DF participated. The tests were performed in an integrated and dynamic circuit format, where each station had a single evaluator. The maximal isometric muscle strength of lower limbs used the mid tight pull position where a traction dynamometer (E-lastic) was fixed to the ground by a metal chain and at its other end a hand strap. The elderly were instructed to perform their maximal concentric movement strength with semi-flexed knees and extended arms for 3-5 seconds with verbal encouragement. The muscle strength was measured in kilograms (kg). In the Walking Test (TC), the elderly should walk through the distance of 10m as fast as possible. Gait speed (m/s) was calculated. In the Time Up and Go (TUG) test, the elderly should get up from a chair without the aid of their arms and walk at a comfortable pace at a distance of three meters, get around an obstacle, return and sit again while time to end the task was measured. A Pearson correlation coefficient was determined between the maximum isometric strength test and the walking and time up and go tests. The statistical package adopted was SPSS (IBM, version 23). RESULTS: The findings revealed a significant and moderate correlation for gait speed and lower limb muscle strength (r = 0.391; p = 0.033) as well as the functional test and lower limb muscle strength level (r = -0.376; p = 0.041). CONCLUSION: Elderly who had higher lower limb strength values obtained the shortest times in the time up and go test and the highest gait speed in the walking test.

Association between lower extremity muscular strength and acute knee injuries in young team‐sport athletes

The purpose of this study was to investigate LE muscular strength variables as potential risk factors for all and non-contact acute knee and ACL injuries in young athletes. A total of 188 young (≤21) male and 174 female basketball and floorball players participated in LE muscular strength tests and were followed up to 3 years. The strength test battery consisted of 1RM leg press, maximal concentric isokinetic (60°/s) quadriceps and hamstrings, and maximal isometric hip abductor strength. The outcomes were a new acute knee or ACL injury and a new acute non-contact knee or ACL injury. A total of 51 (17 in males and 34 in females) new acute knee injuries registered and 17 (one in males and 16 in females) of these were ACL injuries. In the adjusted Cox regression models, only lower maximal hip abduction strength (kg/kg) was significantly associated with an increased risk of all knee injuries in males (HR 1.80 [95% CI, 1.03-3.16] for 1 SD decrease in hip abduction). However, ROC curve analysis showed an area under the curve 0.66 revealing that maximal hip abduction strength test cannot be used as a screening tool for an acute knee injury in young male athletes.

The effects of home-based stair and normal walking exercises on lower extremity functional ability, fall risk factors, and cardiovascular health risk factors in middle-aged older women.

The purpose of this study was to exam 12 weeks of stair and normal walking effects on lower extremity functional ability and cardiovascular health risk factors in middle-aged older women. Twenty-four subjects were assigned either to the stair walking group (SWG, 57.40±6.11 years, n=10) or the normal walking group (NWG, 57.28±16.83 years, n= 14). They performed exercises 3 times per week, 60 min per day for 12 weeks. Lower extremity functional ability (lower extremity muscular strength, walking speed, active and static balance ability, and agility) and cardiovascular health risk factors were compared by time and groups using a two-way repeated analysis of variance and mean values were compared within group using paired t-test. As results, significant time differences were found in lower extremity muscular strength, walking speed and active balance; no time and group interactions were found. Also, significant time differences were found in systolic blood pressure, diastolic blood pressure, total cholesterol, triglycerides, fasting glucose. Significant time and group interactions were found in body fat. In addition, significant time differences within the groups were found in lower extremity muscular strength, walking speed, active balance in SWG and NWG; systolic blood pressure in SWG; systolic blood pressure, diastolic blood pressure, total cholesterol, triglycerides, and fasting glucose in NWG. These results indicated that home-based stair and normal walking exercises can be utilized to improve lower extremity functional ability and cardiovascular health risk factors in middle-aged and older women.

Effect of Sports and Growth on Hamstrings and Quadriceps Development in Young Female Athletes: Cross-Sectional Study.

Context: Lower extremity muscular strength may vary by different sport participation during growth process. Objective: To investigate effect of sport participation and growth by comparing strength of the hamstrings, quadriceps, and hamstrings to quadriceps strength ratio (H:Q ratio) between young female figure skaters and soccer players. Design: Cross-sectional. Settings: Laboratory affiliated with regional sports medicine center. Participants: pediatric and adolescent female athletes. Procedures: Isometric hamstrings and quadriceps strength were measured. Main Outcome Measures: Strength of the hamstrings, quadriceps, and hamstrings to quadriceps strength ratio (H:Q ratio). Statistical Analysis: Effect of sport participation and growth was analyzed through a two-way (two sports: figure skaters and soccer players; three age groups: <12 years, 13–16 years, and >17 years) analysis of covariance. Results: Hamstrings strength was significantly greater in figure skaters than soccer players. Also, hamstring strength of 13–16 years and >17 years was higher compared to <12 years. Additionally, significantly higher H:Q ratio in figure skaters compared to soccer players. Conclusions: There is effect of growth on hamstrings strength among 13–16 years and >17 years compared to <12 years. Figure skaters showed greater hamstrings strength and H:Q ratio than female soccer players.

Association between Physical Fitness and Cardiometabolic Risk of Children and Adolescents in Korea.

BackgroundThis study aimed to investigate the association between physical fitness and cardiometabolic health of Korean children and adolescents.MethodsIn total, 168 participants (89 boys and 79 girls) aged 10–16 years were recruited for the Intervention for Childhood and Adolescent Obesity via Activity and Nutrition Study in 2016. The subjects were categorized into two groups using the definition of metabolic syndrome by the International Diabetes Federation: metabolically unhealthy (with at least two of the five criteria) and healthy groups (with less than one criterion). Correlation analysis of the participants’ general characteristics was performed. Odds ratios (ORs) of physical fitness for cardiometabolic risk were evaluated via logistic regression.ResultsMetabolically unhealthy children showed greater weight, height, and body mass index, higher Children’s Depression Inventory score, and longer screen time than did the metabolically healthy children. Metabolically healthy children showed greater upper and lower extremity muscular strength than did the metabolically unhealthy children (P=0.04 and P<0.001, respectively). In the multiple logistic regression analysis, lower extremity muscle strength was inversely related to the clustered cardiometabolic risk of the children and adolescents with or without adjustment for confounders (OR, 4.32; 95% confidence interval [CI], 1.87–9.97; OR, 7.64; 95% CI, 1.55– 37.74, respectively).ConclusionPhysical fitness, especially lower extremity muscle strength, is significantly inversely associated with individual and clustered cardiometabolic risks in Korean children and adolescents.

The Association between Lower Extremity Muscular Strength and Cognitive Function in a National Sample of Older Adults.

BackgroundWe evaluated the association between lower extremity muscular strength and cognition among older adults in the United States.MethodsData from the 1999–2002 National Health and Nutrition Examination Survey was used to identify 1508 older adults, between 60–85 years. Muscle strengthening activities were assessed via self-report. Participation in physical activity was determined from self-report data. The DSST was used to assess participant executive cognitive functioning tasks of pairing and free recall. A Kin-Com MP isokinetic dynamometer (Chatanooga Group Inc.) was used to assess lower extremity strength, expressed as absolute strength (N), relative strength (N/body weight in kg), and high (<245.75 N) vs. low (≤245.75 N) absolute strength based on the median levels of strength.ResultsLower extremity strength (β = 0.01; 95% CI: 0.0008–0.03; p = 0.039) was associated with higher cognitive performance, independent of age, muscle strengthening activities, physical activity and other covariates. In an adjusted multivariate logistic regression model, those with high (vs. low) strength had a 34% reduced odds of having low cognitive function (OR = 0.66; 95% CI: 0.46–0.93; p = 0.02).ConclusionIn this nationally representative sample of older adults, there was a positive association between elevated lower extremity muscular strength and cognitive functioning.

Are Graded Task-based Interventions The New Remedy For Unfit Overweight And Obese Female Adolescents?

Promotion of physical activity and fitness in adolescent girls who are physically unfit and have less opportunity to practice remains a challenge, particularly in low income communities. It is therefore critical to identify new methods for increasing fitness in this population. PURPOSE: To determine the efficacy of two graded task-based interventions in improving neuromotor fitness among adolescent girls. METHODS: Fifty-six female adolescents (14.4±0.9years) classified as overweight or obesity participated in the study. Participants were randomly allocated to receive either the graded Wii exercises or task-based functional exercise and attended weekly 45min exercise sessions for 14 weeks. During the training period, the participants received supervised exercise training that was systematically graded with simple objects such as sandbags and plastic bottles over 14 sessions. Outcome measures included motor competence, lower extremity muscular strength (both isometric and functional strength), aerobic and anaerobic fitness. Data on enjoyment and ratings of perceived exertion were collected for each session. A repeated measure ANOVA was used to analyse the data with significance level set apriori at p<0.05. RESULTS: At the end of the intervention, it was observed that both groups had significant improvement in motor competence [F(1,54)=0.465,p=0.001], lower extremity muscular strength (isometric strength) [F(1,54)=592.470,p=0.001], lower extremity muscular strength (functional strength) [F(1,54)=15.993, p=0.001], aerobic [F(1,54)=5.586, p=0.022] and anaerobic fitness [F(1,54)=45.792,p=0.001]. Though the two interventions were equally considered to be enjoyable by the participants, there was no difference in outcomes for the two groups. CONCLUSIONS: The two graded task-based interventions may be useful for increasing neuromotor fitness in this population. People working with girls in this age group could implement either of the two depending available resources. We recommend the adoption of these interventions for physical education and/or fitness promotion programmes among girls in low income settings.

Prediction of Lower Extremity Musculoskeletal Injuries for Naval Special Warfare Operators

Lower extremity (LE) musculoskeletal injuries (MSI) are a common and costly occurrence in US NAVY Sea, Air, and Land (SEALs) Operators. Understanding the risk factors associated with LE MSI is an important step in designing injury prevention programs. PURPOSE: To develop a robust mathematical model to predict LE MSI in SEAL Operators. METHODS: 285 subjects (age: 26 ± 5 yrs, height: 179 ± 7 cm, weight: 85 ± 9 kg) participated in testing, including: LE muscular strength and flexibility; balance; body composition; anaerobic power/capacity; and aerobic capacity (VO2max). Medical charts were reviewed for LE MSI 365 days following laboratory testing. The correlated variable sets were identified using Hierarchical Clustering Analysis (HCA). Important features then were selected from the clusters and modeled with regression trees wherein output (predictions) were interpreted as the probability of injury for each individual. To classify observations, a decision threshold was defined that minimized the false positive rate (FPR) conditional on a true positive rate (TPR) of approximately 90% whenever all available variables were utilized. Individuals with predicted probabilities above this threshold were classified as injured. Variables selected in the final models were chosen in a forward fashion, with individual predictors that reduced the FPR without significantly lowering the TPR added to the model. The procedure stopped when no remaining predictor variables were able to produce a model that outperformed the current iteration. RESULTS: LE MSI rate was 13/285 or 4.5%. Each cluster of feature sets from HCA consisted of variables mostly from the same laboratory test category. The final regression tree model contained knee flexion and left knee extension strength (normalized to body weight), fat-free mass (kg), and hamstring flexibility, as the best predictors (TPR of 92.3% and FPR of 2.9%). CONCLUSION: Knee strength, fat-free mass, and hamstring flexibility were important risk factors identified in the machine learning algorithm that accurately classified SEAL Operators with LE MSKI. Alternative high prediction models also can be created using this modeling framework on different variable sets. Supported by ONR N00014-11-1-0929

Adequate Muscular Strength May Help to Reduce Risk of Residual-Specific Mortality: Findings From the National Health and Nutrition Examination Survey.

Muscular strength has been shown to inversely associate with mortality. The purpose of this study was to examine the association between muscular strength and residual-specific mortality among a national sample of US adults, which has yet to be investigated. Here, residual-specific mortality is identified as deaths not inclusive of the 9 leading causes of death as identified by the International Classification of Diseases, 10th revision. Data from the 1999-2002 National Health and Nutrition Examination Survey were used (N = 2171 adults, aged 50-85 y). Participants were followed through 2011, including a median follow-up of 125 months. Lower extremity muscular strength was assessed using maximal isokinetic contractions. After adjusting for all covariates (age, gender, race/ethnicity, body mass index, C-reactive protein, mean arterial pressure, self-report of meeting aerobic-based physical activity guidelines, and physician diagnoses of diabetes), the Cox proportional hazard model demonstrated that for every 25 N increase in lower extremity muscular strength, individuals had a 14% reduced risk of residual-specific death (hazard ratio = 0.86; 95% confidence interval, 0.78-0.96; P = .008). Lower body muscular strength is inversely and independently associated with residual-specific mortality risk, underscoring the importance of adequate muscular strength to prolong survival.