The purpose of this work was to provide a simple method to determine reactive strength during the 6-meter timed hop test (6mTH) and evaluate its association with isokinetic peak torque in patients following anterior cruciate ligament reconstruction (ACLR). Twenty-nine ACLR patients who were at least four months from surgery were included in this analysis. Participants were brought into the laboratory on one occasion to complete functional testing. Quadriceps and hamstring isokinetic testing was completed bilaterally at 60, 180, and 300 deg∙s-1, using extension peak torque from each speed as the outcome measure. The 6mTH was completed bilaterally using a marker-based motion capture system, and reactive strength ratio (RSR) was calculated from the vertical velocity of the pelvis during the test. An adjustment in RSR was made using the velocity of the 6mTH test to account for different strategies employed across participants. Repeated measures correlations were used to determine associations among isokinetic and hop testing variables. A two-way mixed analysis of variance was used to determine differences in isokinetic and hop testing variables between operated and non-operated legs and across male and female participants. Moderate positive associations were found between RSR (and adjusted RSR) and isokinetic peak torque at all speeds (r = .527 to .577). Mean comparisons showed significant main effects for leg and sex. Patients showed significant deficits in their operated versus non-operated legs in all isokinetic and hop testing variables, yet only isokinetic peak torque and timed hop time showed significant differences across male and female groups. Preliminary results are promising but further development is needed to validate other accessible technologies available to calculate reactive strength during functional testing after ACLR. Pending these developments, the effects of movement strategies, demographics, and levels of participation on RSR can then be explored to translate this simple method to clinical environments.

BACKGROUND: Among the medications used to treat knee osteoarthritis (OA), oral patented crystalline glucosamine sulfate (pCGS) and platelet-rich plasma (PRP) have become popular alternatives to painkillers or nonsteroidal anti-inflammatory drugs (NSAIDs). Although studies have shown that pCGS and PRP improve clinical outcomes, no study has compared outcomes between these optional treatments. We compared functional performance outcomes from baseline to the 1-year follow-up (FU) between oral pCGS and PRP in patients with knee OA.
METHODS: Three hundred eighty-two patients receiving oral pCGS and 122 patients receiving PRP injections were enrolled for a review of functional performance outcomes, including a five-time sit-to-stand test (5xSST), time up-and-go test (TUGT), and 3-minute walk distance test (3MWDT). The patients were followed up for one year. The pCGS group received 1500 mg daily, whereas the PRP group received 2 cycles of intra-articular injections at week 0 and week 6. Using propensity score matching based on age, sex, height, weight, BMI, and Kellgren and Lawrence (KL) classification, all three functional performance outcomes were compared between the baseline (pretreatment), 6-week, 12-week, 24-week, and 1-year FUs.
RESULTS: With a ratio of 2:1 (pCGS: PRP), 204 patients in the pCGS group were matched with 102 patients in the PRP group. Compared with the baseline levels, the PRP group showed significant improvements in 5xSST and TUGT outcomes from 6 weeks and significant improvements in 3MWDT outcomes from 12 weeks, whereas the pCGS group showed significant improvements in TUGT outcomes from 6 weeks and significant improvements in 5xSST and 3MWDT outcomes from 12 weeks. At the 24-week and 1-year FU, both groups showed significant improvements in all three functional performance tests without adverse events.
CONCLUSIONS: Although the PRP group showed faster improvements in 5xSST outcomes at six weeks, from the 12-week to 1-year FU, both the pCGS and PRP groups showed significant improvements in 5xSST, TUGT, and 3MWDT outcomes. As the use of PRP is more complicated and invasive than the use of oral pCGS, the benefits and drawbacks of selecting PRP over pCGS in knee OA treatment should be examined.

The proportion of aged populations is increasing worldwide. Exercise has a palliating effect on some adverse implications of aging. Multicomponent training (MCT) is a recommended form of exercise for the aged population. The aims of this research were to (1) study the number of publications regarding MCT in the aged population following an exponential growth rate; (2) identify the journals, authors, and countries that stand out the most in this area; and (3) describe the most common themes and used keywords in this field. The analysis was performed through the traditional laws of bibliometrics, including, Price\'s, Lotka\'s, Bradford\'s, and Zipf\'s law. All documents published in journals indexed in the Web of Science (WoS) Core Collection from 2001 to November 2023 that met the inclusion criteria were included. The 485 documents included in this review revealed that the number of annual publications experienced an exponential growth phase, 15 journals with six or more publications formed the core journals on this topic, and the author Mikel Izquierdo and his collaborative network topped the lists of prominent and prolific co-authors. Spain was the leading country in number of publications. Various thematic lines and keywords regarding strength, sarcopenia, quality of life, falls, balance, dual-task exercise, and cognitive and physical functioning were identified. In conclusion, this work confirmed that research on this topic is going through an exponential growth phase and provided detailed information about the journals, authors, and countries involved in the subject, as well as the keywords most frequently used in the subject matter.

BACKGROUND: The lumbar extensor muscles (LEMs) play an important role in body posture and physical function in older adults. Because lumbar extensor strength decreases more rapidly than limb muscle strength with age, it should be evaluated to aid healthy aging. This study investigated the association between LEM strength and physical performance in community-dwelling older adults.
METHODS: This prospective observational cohort study of spinal sarcopenia (SarcoSpine) was conducted at a single center. One hundred and ten consecutive individuals who completed the baseline survey, including conventional sarcopenic indices, lumbar spine three-dimensional magnetic resonance imaging, isokinetic lumbar extensor strength, and physical performance tests (Short Physical Performance Battery, Berg Balance Scale, and Back Performance Scale [BPS]), were enrolled. A multivariate linear regression analysis was performed to determine the variables for evaluating their association with LEM strength.
RESULTS: Among the conventional sarcopenic indices, gait speed was significantly correlated with Short Physical Performance Battery results and Berg Balance Scale score in men and women. Handgrip strength was significantly correlated with the BPS score for both sexes. In the multivariable linear regression, age (β = -2.12, p < .01) and BPS score (β = -3.54, p = .01, R2 = .29) were independent indicators of LEM strength.
CONCLUSIONS: Our findings reveal the substantial association between LEM strength and BPS score in older women. The targeted intervention aimed at improving the LEMs strength would be needed to enhance physical performance in the aging population.

OBJECTIVE: This study investigated the association of fear of falling with performance-based physical function and low back pain (LBP) among older adults.
METHODS: Cross-sectional study.
METHODS: Participants were selected via convenient sampling from Iran University orthopaedic and/or physiotherapy outpatient clinics, between March 2022 and April 2023.
METHODS: 140 subjects with and without LBP, aged over 60 years, were included.
METHODS: The Falls Efficacy Scale International was used to measure fear of falling. A baseline questionnaire inquired about LBP. Participants performed the Timed Up and Go, 30 s Sit-To-Stand (30s-STS), single leg stance with open and closed eyes and gait speed tests to assess performance-based physical function. Demographic variables including age, gender and body mass index were considered as potential covariates. Bivariate and multivariable linear regression analyses were used to investigate the associations.
RESULTS: A significant association between fear of falling and the 30s-STS test score (β=-0.30, 95% CI -1.27 to -0.28; p=0.00) and the sex (β=0.31, 95% CI 1.53 to 4.83; p=0.00) was confirmed in multivariable analyses. LBP and other performance-based physical function tests were not associated with a fear of falling.
CONCLUSIONS: Fear of falling was significantly associated with lower extremity muscle function, measured by the 30s-STS test and female gender. Older adults with a fear of falling could benefit from interventions that improve lower extremity muscle function. Also, the observed association between the fear of falling and the female sex confirms the need for effective interventions to reduce the fear of falling among older women.

BACKGROUND: Markerless motion capture (MMC) uses video cameras or depth sensors for full body tracking and presents a promising approach for objectively and unobtrusively monitoring functional performance within community settings, to aid clinical decision-making in neurodegenerative diseases such as dementia.
OBJECTIVE: The primary objective of this systematic review was to investigate the application of MMC using full-body tracking, to quantify functional performance in people with dementia, mild cognitive impairment, and Parkinson disease.
METHODS: A systematic search of the Embase, MEDLINE, CINAHL, and Scopus databases was conducted between November 2022 and February 2023, which yielded a total of 1595 results. The inclusion criteria were MMC and full-body tracking. A total of 157 studies were included for full-text screening, out of which 26 eligible studies that met the selection criteria were included in the review. .
RESULTS: Primarily, the selected studies focused on gait analysis (n=24), while other functional tasks, such as sit to stand (n=5) and stepping in place (n=1), were also explored. However, activities of daily living were not evaluated in any of the included studies. MMC models varied across the studies, encompassing depth cameras (n=18) versus standard video cameras (n=5) or mobile phone cameras (n=2) with postprocessing using deep learning models. However, only 6 studies conducted rigorous comparisons with established gold-standard motion capture models.
CONCLUSIONS: Despite its potential as an effective tool for analyzing movement and posture in individuals with dementia, mild cognitive impairment, and Parkinson disease, further research is required to establish the clinical usefulness of MMC in quantifying mobility and functional performance in the real world.

BACKGROUND: Understanding genetic contributors to sarcopenia (age-related loss of muscle strength and mass) is key to finding effective therapies. Variants of the bradykinin receptor 2 (BDKRB2) have been linked to athletic and muscle performance. The rs1799722-9 and rs5810761 T alleles have been shown to be overrepresented in endurance athletes, possibly due to increased transcriptional rates of the receptor. These variants have been rarely studied in older people or people with sarcopenia.
METHODS: We performed a post hoc sub-study of the Leucine and ACE (LACE) inhibitor trial, which enrolled 145 participants aged ≥70 years with low grip strength and low gait speed. Participants\' blood samples were genotyped for rs179972 using TaqMan and rs5810761 by amplification through Hotstar Taq. Genotypes were compared with outcomes of physical performance and body composition measures.
RESULTS: Data from 136 individuals were included in the analysis. For rs1799722 the genotype frequency (TT: 17, CC: 48, CT: 71) remained in Hardy-Weinberg Equilibrium (HWE p = 0.248). There was no difference between the genotypes for six-Minute Walk Distance (6MWD) or Short Physical Performance Battery (SPPB). Men with the TT genotype had a significantly greater 6MWD than other genotypes (TT 400m vs CT 310m vs CC 314m, p = 0.027), and greater leg muscle mass (TT 17.59kg vs CT 15.04kg vs CC 15.65kg, p = 0.007). For rs5810761, the genotype frequency (-9-9: 31, +9+9: 43, -9+9: 60) remained in HWE (p = 0.269). The +9+9 genotype was associated with a significant change in SPPB score at 12 months (-9-9 0 vs -9+9 0 vs +9+9-1, p<0.001), suggesting an improvement. In men, the -9-9 genotype was associated with lower arm fat (-9-9 2.39kg vs -9+9 2.72kg vs +9+9 2.76kg, p = 0.019).
CONCLUSIONS: In men, the rs1799722 TT genotype was associated with longer 6MWD and greater leg muscle mass, while the rs5810761 -9-9 genotype was associated with lower arm fat mass.

We studied the effect of N1-(2,3,4-trimethoxybenzyl)-N2-{2-[(2,3,4-trimethoxybenzyl)amino]ethyl}-1,2-ethanediamine (compound ALM-802) on the physical performance of mice after acute fatigue. The animals\' performance was assessed on a treadmill. The criterion for assessing exercise tolerance was the length of the distance passed when running on a treadmill until complete fatigue. To assess the actoprotective activity of compound ALM-802, we used a method of stepwise increase in load with an initial running speed of 42 cm/sec and its subsequent increase by 5 cm/sec every 5 min. The maximum speed of movement of the treadmill belt is 77 cm/sec. Animals that received compound ALM-802 (2 mg/kg intraperitoneally), 1 day after acute fatigue, ran a distance to complete fatigue that exceeded that of control mice by 68% (387.9±60.5 and 230.6±29.6 m, respectively, p=0.023). The reference drug trimetazidine (30 mg/kg, intraperitoneally) did not have a significant effect on the distance traveled. Compound ALM-802 helps restore physical performance, i.e. exhibits significant actoprotective activity.

UNASSIGNED: Physical performance tests are predictive of mortality and may screen for certain health conditions (e.g., sarcopenia); however, their diagnostic and/or prognostic value has primarily been studied in age-limited or disease-specific cohorts. Our objective was to identify the most salient characteristics associated with three lower quarter balance and strength tests in a cohort of community-dwelling adults.
UNASSIGNED: We applied a stacked elastic net approach on detailed data on sociodemographic, health and health-related behaviors, and biomarker data from the first visit of the Project Baseline Health Study (N = 2,502) to determine which variables were most associated with three physical performance measures: single-legged balance test (SLBT), sitting-rising test (SRT), and 30-second chair-stand test (30CST). Analyses were stratified by age (<65 and ≥65).
UNASSIGNED: Female sex, Black or African American race, lower educational attainment, and health conditions such as non-alcoholic fatty liver disease and cardiovascular conditions (e.g., hypertension) were consistently associated with worse performance across all three tests. Several other health conditions were associated with either better or worse test performance, depending on age group and test. C-reactive protein was the only laboratory value associated with performance across age and test groups with some consistency.
UNASSIGNED: Our results highlighted previously identified and several novel salient factors associated with performance on the SLBT, SRT, and 30CST. These tests could represent affordable, noninvasive biomarkers of prevalent and/or future disease in adult individuals; future research should validate these findings.
UNASSIGNED: ClinicalTrials.gov, identifier NCT03154346, registered on May 15, 2017.

UNASSIGNED: Grier, T, Benedict, T, Mahlmann, O, and Canham-Chervak, M. Relative Strength and Physical Performance in U.S. Army Male and Female Soldiers. J Strength Cond Res 38(8): 1479-1485, 2024-In occupations with high physical demands, strength relative to bodymass is an important measure as it signifies an individual\'s ability to control and move their body mass through space. The purpose of this investigation was to examine physical characteristics, training, and performance based on different magnitudes of relative strength. Subjects were 1,806 male and 319 female US Army soldiers. Sex, age, height, body mass, and physical training data were obtained by an electronic survey. Physical performance was measured by the Army Combat Fitness Test (ACFT), which includes a three-repetition maximum deadlift, standing power throw, hand release push-up, sprint-drag-carry, leg tuck, and two-mile run. The relative body mass deadlifted was calculated and categorized into 4 groups for men and 3 groups for women. An analysis of variance and post hoc least significant difference test were used to evaluate the differences in relative strength and physical performance. Overall, 33% of men deadlifted ≥1.5 times their body mass, while 30% of women deadlifted ≥1.25 times their body mass. Men and women deadlifting the highest percentage of their body mass (≥1.5 times for men and ≥1.25 times for women) outperformed those with lower relative strength within their own sex in all 6 ACFT events. In 4 of the 6 ACFT events, women who deadlifted ≥1.25 times their body mass had similar performance compared with men deadlifting 1 to 1.24 times their body mass and outperformed men deadlifting <1 times their body mass. Greater strength relative to body mass was associated with higher physical performance.