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The rear-foot-elevated split squat is a multijoint exercise used to train the lower extremity musculature in all planes. the benefits include prevention of lower extremity injury, improved gait and sport performance, and increased muscle size and strength. with an anteriorposterior stance, the exercise is performed primarily unilaterally.
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... This exercise can impact the muscle activation of hip and knee extensors in both legs  , which in turn can indirectly improve the quality of life in a non-athletic population, sports performance in athletic populations  , and rehabilitation [8,9] . There are several variations of the lunge exercise such as bilateral/on the floor (In-line, Traditional, Partial lunge, Long lunge or Split squat), focusing on one leg (Bulgarian lunge), using a step (Step-up), with leg/torso movements (Forward step lunge, Walking lunge, Reverse lunge, Lateral lunge), and associated with jump tasks (Jump lunge) [6, , however, research comparing different techniques is scarce. Additionally, to the best of the authors' knowledge, no study has verified the force distribution between legs with different lunge techniques (on the floor or using a step) or with different body positions (upper and lower). ...
... e). Rear-Foot-Elevated Lunge at 50% (RFEL50): RFEL50 was performed with lower limbs in a stride stance.For the RFE technique, the posterior limb was positioned at 50% of the knee height, with all other characteristics similar to the RFEL (Figure Ie). ...
Journal of Biomedical Engineering and Medical Imaging_The lunge exercise is considered a bilateral and multi-joint exercise; in this way, each lower limb presents different force distributions in different techniques and body positions. The purpose of this study was to measure the vertical force distribution between lower limbs in different lunge exercises. Thirty-two young, resistance-trained (male=27, 27±6 years, 174.6±9.6 cm, 79.1±14.2 kg; female=7, 24±4 years, 165.2±2.6 cm, 67.1±13.5 kg) performed 3 different lunge techniques on the floor [traditional (TL), partial (PL), and long (LL)] and two on the step [Rear-Foot-Elevated Lunge (RFEL) and RFEL at 50% (RFEL50)] in two static positions (upper and lower) in a randomized, counterbalanced fashion. For the assessment of the vertical force, two portable force plates were positioned under the anterior and posterior lower limb for all lunge techniques. Factorial ANOVA was used to test differences between exercises (TL, PL, LL, RFEL, and RFEL50), limbs and moments. An alpha of 5% was used. In conclusion, lunge techniques as the TL, PL, and LL presented differences in force between legs and positions, however similarities between techniques, and might be applied for different sports under unilateral conditions. Lunges with step (RFEL or RFEL50) presented high asymmetry between lower limbs and emphasis on the anterior leg.
... Alt ekstremite UNI egzersiz modeli olarak belirlenen MTBS hareketinde sporcuların çömelme derinliğini standart bir pozisyonda yapmaları sağlanmış ve arkada kalan yükseltilmiş bacağın patellasının öndeki bacağın ayak bileği medial malleol hizasına kadar alçalması istenmiştir. Bu ve buna benzer UNI hareket modelleri; ağırlıklı olarak sagital düzlemde fleksiyon ve ekstansiyon içerse de bu egzersizlerde ortak nokta, dar taban yüzeyinin frontal düzlem kontrolü ve ön-arka duruş pozisyonunda, transvers düzlemde kalçalarda meydana gelen rotasyon taleplerini ortaya çıkarmasıdır (McCurdy, 2017). Bu durumun MTBS hareketi içinde, önde kalan ayağın destek bacağının temas yüzeyinin dar olmasına bağlı olarak stabilite kontrolünde azalmaların olabileceğini düşündürmektedir. ...
Bu çalışmanın amacı, farklı yüklerde modifiye edilmiş unilateral squat performansında çömelme derinliği ile bar hızı arasındaki ilişkinin incelenmesidir. Çalışmanın örneklem grubunu, Haliç Üniversitesi Beden Eğitimi ve Spor Yüksekokulu’nda okuyan, en az üç yıl boyunca aktif egzersiz yapan, unilateral (tek taraflı) ve bilateral (iki taraflı) egzersiz modellerine hâkim; yaş 22,90±1,28yıl; boy 175,90±5,36cm ve vücut ağırlığı 75,38±7,78kg olan 10 gönüllü erkek sporcu oluşturmuştur. Verilerin toplanmasında, bar hızının tespit edilmesi için doğrusal hız ölçer olarak PUSH Band™ Pro v2.0 ve squat performansı esnasında çömelme derinliği için üç boyutlu hareket analizi sistemi olan Qualisys Track Manager (QTM) 2020.3 Versiyon (AB, İsveç) kullanılmıştır. Sporcular; modifiye tek bacak squat egzersizi uygulamışlardır. Egzersizi arkadan tutuşta her iki ekstremitede önce ağırlıksız bar da (20kg), ardından random olarak; 1TM’nin %40, %60, %80 yüklerde 5 tekrar yapacak şekilde gerçekleştirmişlerdir. Ölçümlerde, bar üzerine yerleştirilen Push Band aracılığıyla bar hızı hesaplanmış; 3D hareket analiz sistemiyle de farklı yüklerdeki çömelme derinlikleri hesaplanmıştır. Verilerin istatistiksel analizi, IBM SPSS Versiyon 25 programı kullanılarak; tekrarlı ölçümlerde varyans analizi ve ikili karşılaştırmalarda T-testi uygulanarak yapılmıştır. Farklı relatif yüklerde bar hızlarının hemen hepsinde anlamlı farklılıklar elde edilmiştir (p<0,05). Yapılan korelasyon analizi sonucunda bar hızı ve çömelme derinliği arasında anlamlı bir ilişki olmadığı tespit edilmiştir (p>0,05). Sonuç olarak, farklı yüklerdeki bar hızı değişkenlerinin her iki ekstremite de yüklerin artmasıyla anlamlı değişikliklere sebep olmuştur. Yük miktarı, barı hızını azaltacak yönde etkileyen bir parametre olarak değerlendirilebilir.
... Thus, in addition to isokinetic screening, other field-based strength testing protocols are widely implemented in daily practice for assessing unilateral muscular strength, and associated inter-limb asymmetries, to aid in guiding training, rehabilitation and injury prevention. For instance, the rear-foot-elevated-split-squat-test (RFESS) can be regarded as a practical method for measuring unilateral strength in sport . ...
The presence of inter-limb asymmetries can influence strength performance and represent an injury risk factor for team sport athletes. The present study aimed to investigate the effects of changes in resistance loads using different assessment modalities on the magnitude and the direction of inter-limb asymmetry within the same leg. Fifteen young elite soccer players from the same professional academy performed rear-foot-elevated-split-squat-test at different loading conditions (body mass with no overload, 25% of body mass, 50% of body mass 50%), isokinetic knee flexor (concentric 30°·s ⁻¹ , concentric 60°·s ⁻¹ , eccentric 90°·s ⁻¹ ) and extensor (concentric 60°·s ⁻¹ , eccentric 60°·s ⁻¹ ). The outcomes from the agreement analyses suggested moderate level agreement between body mass vs body mass 25% (Kappa = 0.46), with no agreement or fair agreement for the other between-assessment comparison. Our results demonstrated that the magnitude and direction of within-limb strength imbalances were inconsistent when compared within the same assessment under different resistance load conditions.
... UL peak internal rotation exhibited a two fold increase for the compared to the BL condition ( Table 2). The reduced base of support associated with unilateral exercise increases the demand for control about the frontal and transverse planes (McCurdy, 2017). The single base of support also created greater peak moments in all three anatomical planes as well as increased mean moments in the sagittal and transverse planes ( Table 2). ...
The purpose of this study was to quantify the kinetics and kinematics of the unilateral (UL) barbell hip thrust and compare UL biomechanics with the bilateral (BL) barbell hip thrust. Ten resistance trained males performed three sets of three repetitions UL and BL at 10 repetition maximum intensity. The biomechanics of each lift were analysed using 3D motion capture and force plates that were floor mounted and instrumented in to a bespoke rig. Joint kinetics and kinematics were calculated in the sagittal, frontal and transverse planes. The UL condition produced significantly (p<0.05) greater mean moment in the sagittal plane. It was concluded that UL loaded the hip joint to a greater extent than the BL across all three planes. The current study offers novel insight to the biomechanical demand of the unilateral hip thrust and has implications for exercise selection within the physical preparation of athletes.
Properly structured resistance training can induce sport-specific neuromuscular adaptations, such as muscular strength, power, neuromuscular coordination, and joint range of motion in competitive athletes. Adapting traditional weightlifting and powerlifting-associated resistance exercises to be performed unilaterally can also be used to enhance stability. The purpose of this training program is to introduce weightlifting and powerlifting-associated exercises to members of a college-level dance team, with the goal to incorporate unilateral variations of these exercises to enhance stability in preparation for a dance performance. The training program follows the phases of periodization, with unilateral training occurring in the peak phase just before the performance.
The purpose of the study was to determine the unilateral nature of the rear foot elevated split squat (RFESS). Specifically, the production of force by the rear leg was examined to better understand its role, if any, toward successful completion of the exercise. Male volunteers were recruited, (n = 26, age = 23.8 ±4.6 years, mass = 88.1 8 ±10.7kg, height = 1.79±0.1m), who were recreationally trained and engaged in a structured strength and conditioning program including both bilateral and unilateral exercise and had at least two years supervised training experience. Subjects participated in an incremental five repetition maximum protocol, following familiarisation. Kinetic data was recorded via two independent force plates, one integral to the floor and the second mounted on top of solid weightlifting blocks. Kinematic data was captured through three-dimensional motion analysis. A total of 715 repetitions were analysed, the mean contribution of the lead foot to total vertical 16 force production was 84.36 ±3.6%. An almost certainly small positive correlation (rho 17 = 0.25, CI 0.18, 0.33), was found between percentage of force produced by the lead foot, with increasing exercise intensity. A most likely trivial, non-significant correlation 19 (rho =-0.01, CI-0.09,0.06) with rear foot force production, representing the mass of the rear leg. Data from this study does not indicate that the rear foot contributes to the kinetic demands of the exercise and therefore suggests that the RFESS is a valid unilateral exercise.
The paper is now available ahead of print from JSCR here:
This was an oral presentation at the 15th Annual conference of the UKSCA. I discussed the correlation between unilateral leg strength, measured by the Rear foot elevated squat 5RM, and both 20m linear sprint and Modified 5-0-5 change of direction test, in Rugby League players.
The forward walking lunge (WL) and split squat (SSq) are similar exercises that have differences in the eccentric phase, and both can be performed in the ipsilateral or contralateral carrying conditions. This study aimed to determine the effects of dumbbell carrying position on the kinematics and electromyography (EMG) amplitudes of the gluteus medius (Gmed), vastus medialis (VM), vastus lateralis (VL) and biceps femoris during WLs and SSqs.The resistance-trained (RT) and the non-resistance-trained (NT) groups (both n=14) performed ipsilateral WLs, contralateral WLs, ipsilateral SSqs and contralateral SSqs in a randomized order in a simulated training session. The EMG amplitude, expressed as a percentage of the maximal voluntary isometric contraction (%MVIC), and the kinematics, expressed as the range of motion (ROM) of the hip and knee, were measured during 5RM for both legs.The repeated measure analyses of variance showed significant differences between the RT and NT group. The NT showed a smaller knee flexion ROM (p<0.001, η²=0.36) during both types of WLs, whereas the RT group showed a higher eccentric Gmed amplitude (p<0. 001, η²=0.46) during all exercises and a higher eccentric VL amplitude (p<0.001, η²=0.63) during contralateral WLs. Further differences were found between contralateral WLs and ipsilateral WLs in both the RT (p<0.001, η²=0.69) and NT groups (p<0.001, η²=0.80), and contralateral WLs resulted in higher eccentric Gmed amplitudes.Contralateral WLs highly activated the Gmed (90%MVIC); therefore, this exercise can increase the Gmed maximal strength. The ipsilateral loading condition did not increase.
To compare EMG activity of selected hip and knee muscle groups in female athletes performing a modified single-leg squat and the 2-leg squat using the same relative intensity.
Eleven Division I female athletes from a variety of sports (soccer, softball, and track) completed the study. EMG measurements were taken as the subjects completed 3 parallel repetitions at 85% of their 3-repetition maximum on each exercise. Mean and mean peak EMG data from the gluteus medius, hamstrings, and quadriceps and the quadriceps:hamstrings EMG ratio were compared between the 2 exercises.
Statistically higher mean (P < .01) and mean peak (P < .05) gluteus medius and mean and mean peak (P < .01) hamstring EMG activity occurred during the modified single-leg squat. The 2-leg squat produced higher mean and mean peak (P < .05) quadriceps activity and a higher quadriceps:hamstrings EMG ratio (P < .01).
Muscle-recruitment patterns appear to differ between the 2 types of squat exercises when performed at the same relative intensity by female athletes.
To examine hip abductor strength in long-distance runners with iliotibial band syndrome (ITBS), comparing their injured-limb strength to their nonaffected limb and to the limbs of a control group of healthy long-distance runners; and to determine whether correction of strength deficits in the hip abductors of the affected runners through a rehabilitation program correlates with a successful return to running.
Stanford University Sports Medicine Clinics.
24 distance runners with ITBS (14 female, 10 male) were randomly selected from patients presenting to our Runners' Injury Clinic with history and physical examination findings typical for ITBS. The control group of 30 distance runners (14 females, 16 males) were randomly selected from the Stanford University Cross-Country and Track teams.
Group differences in hip abductor strength, as measured by torque generated, were analyzed using separate two-tailed t-tests between the injured limb, non-injured limb, and the noninjured limbs of the control group. Prerehabilitation hip abductor torque for the injured runners was then compared with postrehabilitation torque after a 6-week rehabilitation program.
Hip abductor torque was measured with the Nicholas Manual Muscle Tester (kg), and normalized for differences in height and weight among subjects to units of percent body weight times height (%BWh). Average prerehabilitation hip abductor torque of the injured females was 7.82%BWh versus 9.82%BWh for their noninjured limb and 10.19%BWh for the control group of female runners. Average prerehabilitation hip abductor torque of the injured males was 6.86%BWh versus 8.62%BWh for their noninjured limb and 9.73%BWh for the control group of male runners. All prerehabilitation group differences were statistically significant at the p < 0.05 level. The injured runners were then enrolled in a 6-week standardized rehabilitation protocol with special attention directed to strengthening the gluteus medius. After rehabilitation, the females demonstrated an average increase in hip abductor torque of 34.9% in the injured limb, and the males an average increase of 51.4%. After 6 weeks of rehabilitation, 22 of 24 athletes were pain free with all exercises and able to return to running, and at 6-months follow-up there were no reports of recurrence.
Long distance runners with ITBS have weaker hip abduction strength in the affected leg compared with their unaffected leg and unaffected long-distance runners. Additionally, symptom improvement with a successful return to the preinjury training program parallels improvement in hip abductor strength.
Numerous factors have been identified as potentially increasing the risk of anterior cruciate ligament injury in the female athlete. However, differences between the sexes in lower extremity coordination, particularly hip control, are only minimally understood.
There is no difference in kinematic or electromyographic data during the single-legged squat between men and women.
Descriptive comparison study.
We kinematically and electromyographically analyzed the single-legged squat in 18 intercollegiate athletes (9 male, 9 female). Subjects performed five single-legged squats on their dominant leg, lowering themselves as far as possible and then returning to a standing position without losing balance.
Women demonstrated significantly more ankle dorsiflexion, ankle pronation, hip adduction, hip flexion, hip external rotation, and less trunk lateral flexion than men. These factors were associated with a decreased ability of the women to maintain a varus knee position during the squat as compared with the men. Analysis of all eight tested muscles demonstrated that women had greater muscle activation compared with men. When each muscle was analyzed separately, the rectus femoris muscle activation was found to be statistically greater in women in both the area under the linear envelope and maximal activation data.
Under a physiologic load in a position commonly assumed in sports, women tend to position their entire lower extremity and activate muscles in a manner that could increase strain on the anterior cruciate ligament.
The more accurate description of the anatomy of the glutei and the new biomechanical theory that has been presented describe the abductor mechanism as a system in which the tensor fasciae latae has the primary function of balancing the weight of the body and the non-weight-bearing leg during walking. Gluteus medius with its three parts and phasic functions is responsible for the stabilisation of the hip joint in the initial phase of the gait cycle. It is important also in initiating the major gait determinant of pelvic rotation. Gluteus minimus functions as a primary hip stabiliser during the mid- and late phase of the gait cycle.
The anterior lunge exercise is a closed chain kinetic exercise that has been developed to improve the function of the lower limb and to strengthen the hamstrings and quadriceps, simultaneously. In this study, a three-dimensional biomechanical analysis of this exercise was conducted in order to understand the mechanics of this rehabilitation activity. Experimental conditions were recorded using an active optoelectronic kinematic data capture system (OPTOTRAK), two force plates (AMTI) and electromyography (EMG). Data were collected from healthy male subjects while performing several lunges. When the distance between the toe of the rear leg and the heel of the front leg (lunging distance) was maximum, a large net flexion moment was predicted in the front leg in the extented position. This moment was reversed to a large net extension moment in the flexed position. A large increase in the net extension moment in the rear leg was also predicted as the front knee was bent from 5 degrees to 90 degrees of flexion. These data suggest that quadriceps and hamstring muscles co-contraction occur during a maximum lunge in the front leg when it is in the flexed position.
The purpose of this study was to utilize three-dimensional kinematic (motion) analysis to determine whether gender differences existed in knee valgus kinematics in high school basketball athletes when performing a landing maneuver. The hypothesis of this study was that female athletes would demonstrate greater valgus knee motion (ligament dominance) and greater side-to-side (leg dominance) differences in valgus knee angle at landing. These differences in valgus knee motion may be indicative of decreased dynamic knee joint control in female athletes.
Eighty-one high school basketball players, 47 female and 34 male, volunteered to participate in this study. Valgus knee motion and varus-valgus angles during a drop vertical jump (DVJ) were calculated for each subject. The DVJ maneuver consisted of dropping off of a box, landing and immediately performing a maximum vertical jump. The first landing phase was used for the analysis.
Female athletes landed with greater total valgus knee motion and a greater maximum valgus knee angle than male athletes. Female athletes had significant differences between their dominant and nondominant side in maximum valgus knee angle.
The absence of dynamic knee joint stability may be responsible for increased rates of knee injury in females but is not normally measured in athletes before participation. No method for accurate and practical screening and identification of athletes at increased risk of ACL injury is currently available to target those individuals that would benefit from neuromuscular training before sports participation. Prevention of female ACL injury from five times to equal the rate of males would allow tens of thousands of young females to avoid the potentially devastating effects of ACL injury on their athletic careers.
The purpose of this study was to compare the effects of short-term unilateral resistance training (UL) and bilateral resistance training (BL) with free weights on several tests of unilateral and bilateral lower-body strength and power in men and women. Thirty-eight untrained men and women (mean body mass 78.3 +/- 21.47 kg; age 20.74 +/- 2.6 years) completed the study. The groups trained 2 days per week for 8 weeks with free weights and 2 days per week for 5 of the 8 weeks with plyometric drills. The resistance-training program consisted of a progression from 3 sets of 15 repetitions at 50% of the subject's predicted 1 repetition maximum (1RM) to 6 sets of 5 repetitions at 87% 1RM. Training volume and intensity were equal for each group. The free-weight squat was used to measure unilateral and bilateral strength. Power was measured by the Magaria-Kalamen stair-climb test and the unilateral and bilateral vertical jump test. Analysis of covariance was used to analyze differences between men and women and the interaction of group and gender. Pretest scores were used as the covariate. The UL group improved more than the BL group on the unilateral vertical jump height (p = 0.001) and relative power (p = 0.013). After adjusting for pretest differences, the improved scores on all tests, except for the unilateral squat, were similar between the men and the women. No significant interactions on all tests were found for the men or women comparison between training groups. These results indicate that UL and BL are equally effective for early phase improvement of unilateral and bilateral leg strength and power in untrained men and women.