Squat Test Research Articles

Using the Countermovement Jump Metrics to Assess Dynamic Eccentric Strength: A Preliminary Study.

Background: This study aimed to determine the validity and reliability of the countermovement jump (CMJ) as a dynamic eccentric (Ecc) strength test. Methods: Thirty-three college male student-athletes were recruited to participate in this study. The participants first performed CMJs with the second consisting of one repetition maximum back squat (1RM-BS) test. CMJ and 1RM-BS tests were performed on twin force plates. Results: The CMJ had significant correlations with the Ecc peak force (EccPF), and Ecc mean force (EccMF) of 1RM-BS, respectively (r = 0.61−0.69). Moreover, all parameters had a coefficient of variation (CV) < 10%. The intraclass correlation coefficient (ICC) values were moderate to excellent for each metric using the CMJ (0.94−0.97). The 1RM-BS and CMJ EccPF, EccMF Bland-Altman bias estimate variance ratio is 1.31−1.67, showing a moderate-large correlation in the Bland-Altman plot. Conclusions: CMJ ECC phase kinetics were associated with the 1RM-BS EccPF and EccMF. The CMJ can be an alternative tool for eccentric dynamic strength assessment.

INFLUÊNCIA DO TREINAMENTO DE AGACHAMENTO SOBRE A FORÇA MUSCULAR DOS MEMBROS INFERIORES EM ATLETAS DE KUNG FU

ABSTRACT Introduction Aerobic and anaerobic skills are essential characteristics in Kung Fu competitions. Research concerning their repercussions on athletes’ body composition has gained emphasis due to increased sports competitiveness. Squat training is used in martial arts, but there are no reports about the results in kung fu practitioners. Objective Investigate the effects of squat training on lower limb strength in Kung Fu athletes. Methods 18 martial arts athletes were randomly divided into dynamic preparation activities with stretching (control), squat and half-squat exercises. Results The paired T-test result of the control subjects was P=0.578, and the paired squat test result, relative to the control group, before and after the experiment was P=0.164. The power gain in the body posture trained with squat was 24.14 z 9.81KG, and in the half squat was 23.10±11.75KG. The strength gain in the body posture with half squat is 29.75±10.79KG versus 20.59±12.59KG in the squat test. Conclusion After six weeks of training, both the squat and half squat groups significantly improved the maximum results of the lower limb strength tests. The muscular strength of athletes is improved throughout the range of motion, reducing the injury risk on the athletes. Evidence Level II; Therapeutic Studies - Investigating the result.

Evaluation of the Short-Term Results of Arthroscopic Partial Meniscectomy in Adults

Background: Arthroscopic partial meniscectomy is one of the most common orthopedic procedures; yet enormous evidence of its efficacy is under trial in comparison to repair of the meniscal injury. Objective of this study is to confirm of the clinical findings arthroscopically in case of meniscal injury of the knee joint and find out the results of Arthroscopic partial meniscectomy among the adult people. Methods: This prospective interventional study was conducted from January 2013 to December 2014 at National Institute of Traumatology and Orthopaedic Rehabilitation (NITOR), Dhaka. Twenty (20) patients with meniscus injury were treated in the form of arthroscopic partial meniscectomy. Accelerated rehabilitation protocol was followed. Patients were visited routinely and final outcome evaluation done at 6 months. Lysholm knee scoring scale was used to compare preoperative and postoperative score and to evaluate final outcome. Results: This study was carried out on 20 Patients. Preoperatively all patient had significant knee pain with positive joint line tenderness, McMurrey test, Apley’s grinding test, squat test and Thessaly test. Post operatively significant improvement was found (p&lt;0.05). Mean preoperative Lysholm knee score was 52.8 with SD ± 2.97 and postoperative score was 93.8 with SD ± 4.24. According to Lysholm knee scoring scale, excellent results (95– 100 points) were obtained in 14 patients, good results (85–94 points) in 4 patients, fair in 2 (10%) patient. Conclusion: Arthroscopic partial meniscectomy shows excellent short-term result if the procedure performed early in the adult patients.

Importance of Lower Extremity Muscle Performance and Knee Proprioception During First 60 Degrees of Knee Flexion at Three Months After Anterior Cruciate Ligament Reconstruction

Background: Knee proprioception and neuromuscular control may be important factors contributing to re-injury occurrences. Objectives: To examine lower extremity muscular performance and knee proprioception preoperatively and 3 months after anterior cruciate ligament (ACL) reconstruction. Methods: Twelve participants underwent ACL reconstruction using the hamstring tendon. All participants were assessed for knee proprioceptive sense using an isokinetic dynamometer at 15° and 60° of knee flexion. Lower extremity muscular performance was examined using the single-leg squat test (SLS) with two-dimensional motion analysis in frontal and sagittal planes. Results: Mean absolute error angle at a 15-degree-target angle was significantly lower at three months after ACL reconstruction compared with the preoperative state (P = 0.04). Maximal knee flexion angle of the injured The SLS test showed a lesser knee flexion angle of the injured knee at three months after ACL reconstruction (P = 0.01), and injured knee proprioception at 60 degree-flexion did not significantly improve at the three month-postoperative stage. Conclusions: At three months after ACL reconstruction by hamstring graft tendon, knee proprioceptive sense at an inner range of knee extension improved. However, proprioception at the middle range did not significantly develop. The range of hip and knee motions using SLS related to strength changes that the knee extensor needs to improve, especially in the middle range.

Biyomotor Kazanımda Tenis Temalı Fitness Antrenmanlarının Önemi

Hareketsizliğe bağlı problemlerin önüne geçebilmek için erken yaşlarda kuvvet, sürat, dayanıklılık, esneklik gibi biyomotor özelliklerin çalıştırılması ve geliştirilmesi gerekmektedir. Her yaşa hitap eden doğası ile tenis, hareket ve beceri kazanmak için uygun bir egzersiz olabilir. Bu çalışmanın amacı, tenis temalı fitness antrenmanlarının 12-16 yaş grubu sedanter bireylerin biyomotor yetilerine etkilerini incelemektir. Bu amaçla, 21 sedanter bireyin çalışmaya katılımı sağlandı. 12 haftalık antrenman boyunca tüm katılımcılar müzik, ritim, kuvvet, dayanıklılık, sürat ve koordinasyon egzersizlerini içeren hareketler ile hazırlanmış tenis temalı fitness antrenmanlarına katıldı. Çalışmanın ön test ve son test aşamalarında, katılımcıların biyomotor gelişimlerinin tespit edilmesi amacıyla; denge, esneklik, sürat, çeviklik, el kavrama, dikey sıçrama, anaerobik güç, aerobik güç, tek-çift ayak yatay sıçrama, şınav, mekik, plank ve squat testleri kullanıldı. Ön test ve son test aşamalarında elde edilen veriler, SPSS 25.0 istatistik programı kullanılarak analiz edildi. Bulgular, katılımcıların denge, esneklik, sürat, çeviklik, el kavrama, dikey sıçrama, anaerobik güç, aerobik güç, tek-çift ayak yatay sıçrama, şınav, mekik, plank ve squat ön test ve son test ölçüm sonuçları arasındaki farkların anlamlı olduğunu gösterdi (p

Risk of Single and Multiple Injuries Due to Static Balance and Movement Quality in Physically Active Women.

Background: Static balance is a reliable indicator of the musculoskeletal and nervous systems, which is a basis for movement stabilization development. The disorders in this area may increase injury risk (IR). This study investigated the musculoskeletal injury risk due to static balance and movement quality regarding single and multiple injury occurrences in physically active women. Methods: The study sample was 88 women aged 21.48 ± 1.56. The injury data were obtained with a questionnaire, and Deep Squat (DS), In-line lunge (IL), and Hurdle Step (HS) tests were conducted. Static balance was assessed with a stabilometric platform measured center of gravity area circle (AC) and path length (PL) with open (OE) and closed eyes (CE), maintaining a standing position for the 30 s. Results: The logistic regression models revealed the general injury occurrence was predicted by AC-CE (OR = 0.70; p = 0.03) and IL (OR = 0.49; p = 0.03), and the two-factor model AC-CE*IL, (OR = 1.40; p < 0.01). When the single injury was predicted by the same factors AC-CE (OR = 0.49; p < 0.01), IL (OR = 0.36; p = 0.01), and AC-CE*IL (OR = 1.58; p < 0.01). Conclusion: Static balance and movement stability predict musculoskeletal injury risk alone and in one model. A further study is needed to verify the efficiency of indicated factors in prospective terms. Using both quantitative and qualitative tests could be helpful in IR prediction.

Antioxidant vitamin supplementation on muscle adaptations to resistance training: A double-blind, randomized controlled trial

ObjectivesThe aim of this study was to examine whether antioxidant vitamin supplementation with vitamin C (VitC) and vitamin E (VitE) affects the hypertrophic and functional adaptations to resistance training in trained men. MethodsThis was a double-blind, randomized controlled trial in which participants were supplemented daily with VitC and VitE ( n = 12) or placebo ( n = 11) while completing a 10-wk resistance training program accompanied by a dietary intervention (300 kcal surplus and adequate protein intake) designed to optimize hypertrophy. Body composition (dual-energy x-ray absorptiometry), handgrip strength, and one-repetition maximum (1-RM), maximal force (F0), velocity (V0), and power (Pmax) were measured in bench press (BP) and squat (SQ) tests conducted before and after the intervention. To detect between-group differences, multiple-mixed analysis of variance, standardized differences, and qualitative differences were estimated. Relative changes within each group were assessed using a paired Student's t test. ResultsIn both groups, similar improvements were produced in BP 1-RM , SQ 1-RM SQ, and BP F0 (P < 0.05) after the resistance training program. A small effect size was observed for BP 1-RM (d = 0.53), BP F0 (d = 0.48), and SQ 1-RM (d = –0.39), but not for SQ F0 (d = 0.03). Dominant handgrip strength was significantly increased only in the placebo group (P < 0.05). According to body composition data, a significant increase was produced in upper body fat-free mass soft tissue (FFMST; P < 0.05) in the placebo group, whereas neither total nor segmental FFMST was increased in the vitamin group. Small intervention effect sizes were observed for upper body FFSMT (d = 0.32), non-dominant and dominant leg FFMST (d = –0.39; d = –0.42). Although a significant increase in total body fat was observed in both groups (P < 0.05) only the placebo group showed an increase in visceral adipose tissue (P < 0.05), showing a substantial intervention effect (d = 0.85). ConclusionsThe data indicated that, although VitC/VitE supplementation seemed to blunt upper body strength and hypertrophy adaptations to resistance training, it could also mitigate gains in visceral adipose tissue elicited by an energy surplus.

Immediate effects of hip strap and foot orthoses on self-reported measures and lower limb kinematics during functional tasks in individuals with patellofemoral osteoarthritis: protocol for a randomised crossover clinical trial

BackgroundElevated patellofemoral joint stress has been associated with patellofemoral osteoarthritis (PFOA). Changes in lower limb kinematics, such as excessive femoral adduction and internal rotation and excessive rearfoot eversion during the stance phase of functional activities, may increase patellofemoral stress. There is a lack of studies that assess the effects of interventions for controlling femur and subtalar joint movements during functional activities on self-reported measures in individuals with PFOA. Thus, the primary aim of the study is to determine the immediate effects of the hip strap and foot orthoses during level-ground walking and the single-leg squat test on self-reported outcomes. The secondary aim is to investigate whether the hip strap and foot orthoses result in the kinematic changes that these devices are purported to cause.MethodsTwenty-nine individuals with PFOA aged 50 years or older will take part in the study. The main outcome is pain intensity. The secondary outcomes are other self-reported measures (global rating of change, acceptable state of symptoms, ease of performance, and confidence) and lower limb kinematics (peak femoral adduction and internal rotation, and peak rearfoot eversion). These outcomes will be assessed during functional tasks performed under three conditions: (i) control condition, (ii) hip strap intervention, and (iii) foot orthoses intervention. To investigate whether these interventions result in the lower limb kinematic changes that they are purported to cause, three-dimensional kinematics of the femur and rearfoot will be captured during each task. Linear mixed models with two fixed factors will be used to test associations between the interventions (control, hip strap, and foot orthoses) and conditions (level-ground walking and single-leg squat test) as well as interactions between the interventions and conditions.DiscussionTo the best of the authors’ knowledge, this is the first study to evaluate the immediate effects of the hip strap and foot orthoses on self-reported measures and lower limb kinematics during functional tasks in individuals with PFOA. The findings of this study will enable future trials to investigate the effects of these interventions in rehabilitation programmes.Trial registrationClinicalTrials.gov NCT04332900. Registered on 3 April 2020.

Differences In Blood-flow Patterns Of The Carotid Artery Between Two Exercise Modalities At Three Intensities

Endothelial shear stress (ESS), frictional force produced by red blood cells on endothelial cells, helps to maintain endothelial homeostasis, and help to determine blood flow patterns. Purpose: This study seeks to determine exercise-induced blood flow patterns in the carotid artery during different exercise modalities (back squat and treadmill running) at 3 different intensities. Methods: Fourteen participants (7 males and 7 females) participated in a repeated measures study design. Three sessions were performed to obtain baseline measurements, 1-repetition maximum back squat test (1RM Squat), and treadmill maximum oxygen uptake test (VO2max). Two more sessions, for squat and treadmill, were randomized within a week after the baseline measurements. Squat intensities selected: low = 45% 1RM, moderate = 65% 1RM, and high = 85% 1RM. Running intensities were selected using blood lactate levels: low = 0-2 mmol/L, moderate = 2-4 mmol/L, and high >4.0 mmol/L from the VO2max test. Blood flow patterns of the carotid artery (diameter and blood flow velocity) and presence of turbulence determined by calculation of Reynolds number (Re), were obtained using ultrasound imaging and Doppler. Data analysis used a 2-way repeated-measures ANOVA, with Holm-Bonferroni post-hoc analysis to determine pairwise differences between modalities and intensity. Statistical significance was set at α = 0.05. Results: There were main effects and interaction between intensity and exercise modalities (p < 0.05) for ESS. Pairwise comparisons showed difference in moderate (p < 0.05) and high (p < 0.05) intensity in both modalities (Figure 1A) compared to low intensity. Similarly, there was a main effect of exercise intensity (p < 0.05) for Re. Pairwise comparisons indicate significant difference (p < 0.05) in high intensity in both modalities (Figure 1B) compared to low intensity. Conclusion: Results indicated turbulent blood flow patterns across all intensities and modalities; however, high intensity treadmill yields greater turbulent blood flow. Furthermore, ESS increases linearly as intensity increases, with greater magnitude in moderate and high intensity treadmill. Clinicians should be aware of differences in carotid artery hemodynamics at different exercise intensities and modes to prescribe better exercise interventions.

Relationship between Lower Extremity Fitness Levels and Injury Risk among Recreational Alpine Skiers: A Prospective Cohort Study.

Background: Although the importance of physical fitness for injury prevention is recognized in sports medicine and rehabilitation, few studies have investigated this factor among recreational alpine skiers. Objective: To determine the effect of lower extremity fitness on the risk and severity of injury among recreational alpine skiers. Method: This prospective cohort study involved 117 recreational skiers at two alpine resorts during the 2021–2022 winter season. Anthropometric characteristics, skiing skills, and lower extremity agility (hexagon test), balance (Y-Balance Test), and endurance (60-s squat test) were assessed before the winter season. All of the participants were divided into an injured group and an uninjured group, based on whether an injury was recorded throughout the season. Results: In binary logistic regression, the hexagon test duration and composite Y-Balance Test score were significant injury risk factors (p < 0.05). Ordinal polytomous logistic regression revealed no significant factors for injury severity (p > 0.05). Conclusions: Recreational alpine skiers with inferior lower extremity agility or balance may have a higher injury risk and this must be considered when assessing individual risk. In the context of injury prevention, regular neuromuscular training and testing, including agility and balance aspects should be recommended to skiers.

Acute neuromuscular and hormonal responses to 20 versus 40% velocity loss in males and females before and after 8 weeks of velocity‐loss resistance training

New Findings What is the central question of this study? Do males and females differ in fatiguability during dynamic loadings, and what are the acute neuromuscular and hormonal responses to 20 versus 40% velocity‐loss resistance loadings? How does an 8‐week velocity‐loss resistance training period modify acute neuromuscular and hormonal responses in males and females? What is the main finding and its importance? Using resistance training methods that regulated the within‐set fatigue limit, males appeared to be more susceptible to fatigue than females before the training period. This between‐sex difference was diminished after training. The predominant mechanisms of fatigue from 20 and 40% velocity‐based resistance training appear to be within the musculature. Scientific examination of velocity‐based resistance training (VBRT) has increased recently, but how males and females respond to different VBRT protocols or how these acute responses are modified after a period of training is unknown. Habitually resistance‐trained males and females followed either a 20 or 40% velocity‐loss programme for 8 weeks. Acute squat loading tests (five sets, 70% one‐repetition maximum load, 3 min rest) were performed before and after the training period. Tests of maximum neuromuscular performance and blood sampling were conducted before, within 10 min of completion (POST) and 24 h after each acute loading test. Testing included countermovement jump, resting femoral nerve electrical stimulation and bilateral isometric leg press. Blood samples were analysed for whole‐blood lactate, serum testosterone, cortisol, growth hormone and creatine kinase concentrations. Countermovement jump height, maximum isometric bilateral leg‐press force and the force from a 10 Hz doublet decreased in all groups at POST after 20 and 40% velocity loss. Only males showed reduced force from the 100 Hz doublet and voluntary force over 100 ms at POST before training. The 40% velocity loss led to increased blood lactate and growth hormone responses before training in both males and females. After training, more systematic and equivalent responses in force over 100 ms, force from a 100 Hz doublet and blood lactate were observed regardless of sex/VBRT protocol. Overall, acute responses were greater from 40% VBRT, and males were more susceptible to acute loss in force production capacity before the training period. These VBRT protocol‐ and sex‐related differences were diminished after training.

A Data Analytics Approach to Assess the Functional and Physical Performance of Female Soccer Players: A Cohort Design.

Background and Objectives: The aim of this study was twofold: (i) to observe the individual results of fitness status [countermovement jump (CMJ)], hop test, linear sprinting time, stride frequency, stride distance, force–power–velocity, peak power maximal and maximal speed, and repeated sprint ability (RSA) and functional performance (overhead squat, single-leg squat test, dumbbell hip-hinge, Thomas test, hip extension, and internal and external hip rotators) and (ii) to analyze the relationship between anthropometrical measures and values of fitness status with % of difference in the Thomas test, hip extension, and internal and external hip rotators. Materials and Methods: The study followed a cohort design. Sixteen female soccer players competing in the second division of the Spanish league were monitored during the first days of the pre-season. These players were evaluated three times during the preseason of the cohort period. The dataset showed a negative moderate correlation between time and percentage of difference in hip angle and another positive moderate correlation between maximal sprint and percentage of difference in hip angle (r = −0.54, p = 0.02 and r = 0.53, p = 0.04), respectively. The correlations of stride time and distance with hip extension are interesting, as professional soccer players should have higher levels of hip flexor flexibility during the stride phase, recoil of the instep kick action.

Efficacy of neuromotor and functional training on musculoskeletal fitness among middle aged women

The aim of this study was to determine the Efficacy of Neuromotor and Functional training on musculoskeletal fitness among middle aged women. To achieve the purpose of the study thirty six middle aged women were randomly selected as subjects and their age ranged between 45 to 50 years. They were divided into three groups. Group I acted as Neuromotor training group (n=12), Group II acted as Functional training (n=12) and Group III acted as control group (n=12). The experimental groups participated in the respective training programme for a period of ten weeks. The subjects of the control group participated on their routine activities. To assess Muscular strength was assessed via a one repetition maximum (1-RM) bench press and squat test. Muscular endurance was evaluated using a curl-up test. Flexibility was assessed using a modified sit-and-reach test and the best of three results was recorded to the nearest 0.1 cm as the final value. Results indicated significant (p< 0.05) increases in muscular strength (1-RM bench press, 1-RM squat), muscular endurance (curl-up) and increases in flexibility (sit-and-reach) within each group following training. It was concluded that both training programs are equally beneficial for increasing musculoskeletal fitness in middle aged women.

The Effect of Sportsmetrics on the Performance and Knee Valgus During Landing of Female Soccer Players

Purpose: Dynamic knee valgus and poor technique during landing are not only key risk factors for lower extremity injuries especially knee injury, but also can reduce the performance of athletes in the field. Sportsmetrics soccer training is one of the successful knee injury prevention and enhancement performance protocols for female soccer players. Because the effect of sportsmetrics soccer training has not been investigated on the performance and knee valgus during landing in female soccer players, we aimed to investigate this subject. Methods: The current field-trial study was conducted on 24 female soccer players with dynamic knee valgus that were randomly divided into two groups: the training group (TG) and the control group (CG). The assessment tests were the agility t-test, 40-yard test, vertical jump test, double leg squat test, and valgus landing error scoring system test (LESS). The TG group participated in sportsmetrics soccer training regularly for 6 weeks, three 90-min sessions a week. Analysis of covariance was used to analyze the obtained data (P&lt;0.05). Results: Six weeks of sportsmetrics soccer training in the TG group not only reduced dynamic knee valgus during landing (51% reduction, F=171.8, P=0.01) but also improved performance factors significantly: agility (0.50 s reduction, F=23.29, P=0.01), power (2.50 cm increase, F=13.20, P=0.01) and speed (0.30 s reduction, F=23.66, P=0.01). Conclusion: Sportsmetrics soccer training is strongly suggested for soccer players exposed to knee injuries due to dynamic knee valgus during landing.

Assessment of Dynamic Knee Valgus between Lateral Step-Down Test and Running in Female Runners with and without Patellofemoral Pain Using Two-Dimensional Video Analysis.

Dynamic knee valgus (DKV) is a frontal plane knee kinematic alteration that has been associated with patellofemoral pain (PFP) in female runners. DKV is commonly assessed in clinical practice by measuring frontal plane knee projection angle (FPPA) during squat tests. However, it remains unclear whether the DKV observed in these tests is similar to or correlates with that observed during running in female runners. The aims of this cross-sectional study were to correlate and compare DKV, by measuring FPPA values, in a lateral step-down (LSD) squat test and running in female runners with and without PFP. A two-dimensional (2D) video analysis of the LSD test and running was carried out for 21 asymptomatic female runners and 17 PFP female runners in order to determine FPPA values. A Pearson correlation test and a factorial ANOVA with Bonferroni post hoc correction were used for statistical analysis. The FPPAs recorded in the LSD test were significantly higher than those recorded during running in the asymptomatic (16.32° ± 5.38 vs. 4.02° ± 3.26, p < 0.01) and PFP groups (17.54° ± 7.25 vs. 4.64° ± 3.62, p < 0.01). No significant differences were found in FPPA values between asymptomatic and PFP runners during the LSD test (16.32° ± 5.38 vs. 17.54° ± 7.25, p = 0.55) and running (4.02° ± 3.26 vs. 4.64° ± 3.62, p = 0.58). There was a small (r < 0.3) and non-significant (p > 0.05) correlation in FPPAs between the LSD test and running in both groups. According to our results, DKV was not similar during the LSD test and running, and there was no significant correlation in FPPA values between the LSD test and running in both groups. Therefore, clinicians and therapists should be aware of these findings when using the LSD test in clinical practice to evaluate DKV in female runners with or without PFP.

Designing and testing basic protocol for medium fast bowler to increase the speed and accuracy

Background: The skill of medium fast bowlers to consistently maintain their pace and accuracy while bowling , help them to not allow batsman to settle in their inning, and benefit to bowlers to take their wickets. In field of cricket the various parameters like bowling speed and accuracy have been a major area of research. Aim. To study the effect of designed and tested basic protocol on medium fast bowlers speed and accuracy. To study the Kinematic measures in the first four overs of medium fast bowling. To study the effect of a designed based training on, 6RM Squat Test , 6 RM Bench Press Test and Yo-Yo Intermittent Recovery Test Level 1 ( YYIRTL1). Material and Methods: 60 State Level Male Medium Fast Cricket Bowlers ( mean age under 19 boys ) were divided into two group one group will going to do subject specific protocol based training for 6 weeks and another will be an control group.

The influence of caffeinated and non-caffeinated multi-ingredient pre-workout supplements on resistance exercise performance and subjective outcomes.

ABSTRACTBackgroundThere is substantial consumer and practitioner interest in an emerging supplement class known as multi-ingredient pre-workout supplements (MIPS), largely due to their prevalence in resistance training communities as well as research findings demonstrating the ergogenic impact of caffeine on muscular performance. However, limited research has examined the potential efficacy of non-caffeinated MIPS, despite their growing popularity among those who are caffeine-sensitive or who train later in the day.MethodsTwenty-four resistance-trained college-aged males (n = 12) and females (n = 12) completed three visits in which they ingested either a caffeinated MIPS (C), an otherwise identical non-caffeinated MIPS (NC), or placebo in a double-blind, counterbalanced, crossover fashion. Squat isometric peak force (PFiso), rate of force development (RFD), and isokinetic performance were assessed. Upper and lower body maximal muscular strength and endurance were evaluated using the bench press and leg press, respectively. Visual analog scales for energy, focus, and fatigue were completed five times throughout the testing protocol. The effects of supplementation and biological sex on all variables were examined using linear mixed effects models.ResultsSignificantly greater PFiso was observed in both C (b: 0.36 transformed units [0.09, 0.62]) and NC (b: 0.32 transformed units [95% CI: 0.05, 0.58]) conditions, relative to placebo. Early RFD (RFD50) may have been higher with supplementation, particularly in females, with no effects for late RFD (RFD200) or peak RFD. In addition, increases in subjective energy after supplement ingestion were noted for C, but not NC. No effects of supplementation on traditional resistance exercise performance or isokinetic squat performance were observed, other than a lower leg press one-repetition maximum for males in the NC condition.ConclusionsThese data indicate that acute ingestion of either a caffeinated or non-caffeinated pre-workout formulation improved maximal force production during an isometric squat test but did not provide additional benefit to leg press, bench press, or isokinetic squat performance over placebo, within the context of a laboratory environment. The consumption of a caffeinated, but not non-caffeinated, MIPS increased subjective ratings of energy over placebo when assessed as part of a testing battery.

Feasibility of the wingate anaerobic exercise test as a clinical measure in patients with juvenile dermatomyositis

BackgroundCore sets, while widely adopted for clinical assessment in juvenile dermatomyositis (JDM), have some drawbacks – they are time consuming, were developed primarily for research, and require an experienced multidisciplinary team. We propose the Wingate Anaerobic Test, a 30-s all out test performed on a cycle ergometer, as a potential alternative; it is valid and reliable in this patient population. We aimed to determine the feasibility of performing the Wingate test as part of a typical clinic visit, and to determine if it is correlated to current measures of disease activity.MethodsPatients 5–18 years of age, with JDM, were recruited from the JDM clinic at a large Canadian academic children’s hospital. Participants underwent a standard clinic assessment, then completed a Wingate test at the end of the visit.ResultsTwenty-six patients participated in the study, representing a recruitment rate of 81%; of those, 88% were able to complete the Wingate test. Patients liked the Wingate test and felt it should be included as a regular clinic test. Absolute peak power (watts) on the Wingate test was strongly correlated to the manual muscle test (MMT-8) and the timed squat test. Relative peak power (watts/kg) on the Wingate test was strongly correlated to the timed squat test and the Childhood Myositis Assessment Scale (CMAS). Exploratory principal components analysis revealed that Wingate relative average power explained almost 2/3 of the variance of the CMAS, MMT and timed squats combined.ConclusionThe Wingate test is a feasible test for children with JDM and correlates well with standard clinical assessments. Given its brevity, it has the potential to replace more standard measures of physical function currently used in clinical assessments for children with JDM. Future work should focus on how best to operationalize Wingate testing in clinic without the use of dedicated personnel.

Strength Deficit in Elite Young Rugby Players: Differences Between Playing Positions and Associations With Sprint and Jump Performance.

Zabaloy, S, Giráldez, J, Fink, B, Alcaraz, PE, Pereira, LA, Freitas, TT, and Loturco, I. Strength deficit in elite young rugby players: Differences between playing positions and associations with sprint and jump performance. J Strength Cond Res 36(4): 920-926, 2022-The aims of this study were twofold: to compare the strength-related performance between young forwards and backs rugby players and to examine the correlations between strength deficit (SDef), strength parameters, and sprint and jump performance. Fifty-seven male rugby players (mean ± SD: age, 17.4 ± 1.3 years) performed anthropometric and body composition assessments, vertical jumps, 30-m sprint, and squat (SQ) and bench press (BP) 1-repetition maximum tests (1RM SQ and BP). The differences in the tested variables between positions were analyzed through an independent t-test. A Pearson's correlation coefficient was used to assess the relationships among the variables. Significant differences were observed for anthropometric and body composition measures and jump and sprint performance between positions (p < 0.05; effect size [ES]: 0.60-1.34), except for 5-m velocity (p = 0.080; ES: 0.57). Backs demonstrated higher relative 1RM than forwards in both exercises (p = 0.009 and p = 0.008; ES = 0.88 and 0.91, for SQ and BP, respectively). In addition, backs demonstrated lower SDef from 70 to 90% 1RM (p < 0.048) but small-to-moderate nonsignificant lower SDef against lighter loads compared with forwards (50-60% 1RM). Overall, SDef across all loads (r: -0.378 to -0.529) and 1RM SQ (r: 0.504 to -0.590) were significantly related to sprint performance. Therefore, young rugby players who present lower magnitudes of SDef and superior 1RM SQ performance tend to be faster in linear sprints.

Validity and inter-rater reliability of ankle motion observed during a single leg squat.

BackgroundThe single leg squat (SLS) test is a clinical functional test commonly used to evaluate clinically aberrant movement patterns of the knee. The SLS could be an interesting option to analyze ankle control in the frontal plane during dynamic load analysis. However, to date, there are no studies that have analyzed the associations between the increased subtalar joint pronation by navicular drop (ND) test and ankle control with single leg squat (SLSankle) using a three-point scale. The purpose of this study was to evaluate the reliability of a clinical observation method to assess and determine the relationship between navicular drop (ND) and ankle control on the SLSankle score.MethodsA total of fifty-five healthy, physically active (31 females and 24 males) volunteers participated in this study. The degree of subtalar pronation was assessed through the ND test, and the ankle control was defined as the ankle displacement in the frontal plane during the SLS.ResultsWe found good intra-rater and inter-rater agreement during SLSankle, with Kappa values from 0.731 to 0.750. The relationship between the SLSankle and ND was significant ; the Spearman’s rank correlation coefficient was 0.504 (p < 0.05).ConclusionsThe SLSankle score supplied the clinical practice with a reliable and valid alternative for quantifying foot mobility in comparison to the ND test.