scholarly journals Muscle Activation and Kinematic Analysis during the Inclined Leg Press Exercise in Young Females

Author(s):  
Isabel Martín-Fuentes ◽  
José M. Oliva-Lozano ◽  
José M. Muyor

Knee joint muscle activation imbalances, especially weakness in the vastus medialis oblique, are related to patellofemoral pain within the female population. The available literature presents the leg press as an exercise which potentially targets vastus medialis oblique activation, thus reducing imbalances in the quadriceps muscles. The main aim of the present study was to compare thigh muscle activation and kinematic parameters under different conditions during the inclined leg press exercise in a young female population. A cross-sectional study was conducted on 10 young, trained females. Muscle activation of the vastus medialis oblique, vastus lateralis, rectus femoris and gluteus medialis was analyzed under five different inclined leg press conditions, modifying the feet rotation (0–45° external rotation) and the stance width (100–150% hip width) on the footplate. All the conditions were performed at two different movement velocities: controlled velocity (2″ eccentric–2″ concentric) and maximal intended velocity. Mean propulsive velocity, maximum velocity and maximum power were also assessed. The results show that both controlled velocity conditions and maximal intended velocity conditions elicited a similar muscle activation pattern with greater activation during the concentric phase (p < 0.001, ηp2 = 0.96). The maximal intended velocity conditions showed greater overall muscle activation (p < 0.001, ηp2 = 0.91). The vastus medialis oblique presented the greatest muscle activation, followed by the rectus femoris, vastus lateralis and, the gluteus medialis. Furthermore, the inclined leg press condition with 0º feet rotation, 100% hip width distance and the maximal intended velocity generated the greatest kinematic parameter outputs. In conclusion, the inclined leg press exercise might be an optimal exercise to target vastus medialis activation regardless of the feet rotation and stance width conditions.

2021 ◽  
pp. 194173812110163
Author(s):  
Isabel Martín-Fuentes ◽  
José M. Oliva-Lozano ◽  
José M. Muyor

Background: The leg press is one of the most typical exercises for strengthening the lower limbs. The objectives of this study were to compare 5 inclined leg press exercise conditions, varying the feet width stance (100% or 150% hip width), the feet rotation (0° or 45° external rotation) on the footplate and using 2 different movement velocities (MVs; maximum intended, and 2:2 seconds steady-paced velocities) to determine their effect on muscle activation as well as on the kinematic parameters between trained men and trained women. Hypotheses: There will be no significant differences in muscle activation with regard to the feet position. The higher the MV, the greater the muscle activation. Study Design: A cross-sectional cohort study. Level of Evidence: Level 3. Methods: A repeated-measures between-group design was performed to examine muscle activation and kinematic parameters for the different conditions between gender groups. The level of significance was set at alpha = 0.05 for all statistical analyses. Results: Muscle activation presented no differences between conditions regarding feet width stance or feet rotation. Furthermore, muscle activation was greater during positive phases than negative phases of the exercise for all conditions and was also greater under maximum intended velocity conditions compared with steady-paced conditions. Otherwise, the muscle activation pattern presented slight differences by gender. In men, the greatest muscle activation was for the vastus medialis, followed by the vastus lateralis (VL), rectus femoris (RF), and gluteus medialis (GMED), while in women, the greatest muscle activation was for the vastus medialis, followed by the RF, VL, and GMED. Finally, greater mean propulsive velocity, maximum velocity, maximum power, and footplate displacement values were reported for men than for women under all the conditions. Conclusion: The inclined leg press exercise produces the highest muscle activation in the vastus medialis, regardless of the velocity, feet stance, or gender. Clinical Relevance: Given that there are no differences in muscle activation regarding the feet stance, a participant’s preferred feet stance should be encouraged during the inclined leg press exercise. Furthermore, the MV would preferably depend on the session objective (a training or a rehabilitation program), being aware that there is greater muscle activation at higher speeds. The inclined leg press exercise could be performed as a closed kinetic chain exercise when the main objective is to activate the vastus medialis.


Author(s):  
Isabel Martín-Fuentes ◽  
José M. Oliva-Lozano ◽  
José M. Muyor

The aim of this study was to analyze the literature on muscle activation measured by surface electromyography (sEMG) of the muscles recruited when performing the leg press exercise and its variants. The Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to report this review. The search was carried out using the PubMed, Scopus, and Web of Science electronic databases. The articles selected met the following inclusion criteria: (a) a cross-sectional or longitudinal study design; (b) neuromuscular activation assessed during the leg press exercise, or its variants; (c) muscle activation data collected using sEMG; and (d) study samples comprising healthy and trained participants. The main findings indicate that the leg press exercise elicited the greatest sEMG activity from the quadriceps muscle complex, which was shown to be greater as the knee flexion angle increased. In conclusion, (1) the vastus lateralis and vastus medialis elicited the greatest muscle activation during the leg press exercise, followed closely by the rectus femoris; (2) the biceps femoris and the gastrocnemius medialis showed greater muscular activity as the knee reached full extension, whereas the vastus lateralis and medialis, the rectus femoris, and the tibialis anterior showed a decreasing muscular activity pattern as the knee reached full extension; (3) evidence on the influence of kinematics modifications over sEMG during leg press variants is still not compelling as very few studies match their findings.


Author(s):  
Mohamadreza Hatefi ◽  
Farideh Babakhani ◽  
Ramin Balouchi ◽  
Amir Letafatkar ◽  
Brian J. Wallace

AbstractThe purpose of this study was to compare muscle activation during the squat with different hip rotations (neutral, 15, 30, and 45° of internal and external hip rotation) in subjects with and without Genu Varum deformity deformity. Surface electromyography were recorded from 32 men with (n=16) and without (n=16) Genu Varum deformity. In the Genu Varum deformity group, the squats with 30, 45 and 15° of internal rotations of the hip showed significantly greater gluteus medius activation as compared to other positions. Moreover, the tensor fascia lata activity increased with greater external rotation of the hip, and significantly more than hip internal rotations (p<0.05). For vastus medialis and vastus lateralis, both hip internal and external rotation showed a significantly greater activation compared to the neutral hip positions (p<0.05). There were significant differences in the gluteus medius:tensor fascia lata activity ratio (p=0.001) and the vastus medialis: vastus lateralis activity ratio (p=0.001) between the different hip positions in the Genu Varum deformity and healthy groups. These results demonstrate that muscle activation patterns varied significantly with the position of different hip rotation in both groups. Those with Genu Varum deformity may use this information to aid in an injury prevention strategy by choosing squat positioning that favorably alters muscle activation patterns.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10909
Author(s):  
Lucas Túlio Lacerda ◽  
Rodrigo Otávio Marra-Lopes ◽  
Marcel Bahia Lanza ◽  
Rodrigo César Ribeiro Diniz ◽  
Fernando Vitor Lima ◽  
...  

Background This study investigated the effects of two 14-week resistance training protocols with different repetition duration (RD) performed to muscle failure (MF) on gains in strength and muscle hypertrophy as well as on normalized electromyographic (EMG) amplitude and force-angle relationships. Methods The left and right legs of ten untrained males were assigned to either one of the two protocols (2-s or 6-s RD) incorporating unilateral knee extension exercise. Both protocols were performed with 3–4 sets, 50–60% of the one-repetition maximum (1RM), and 3 min rest. Rectus femoris and vastus lateralis cross-sectional areas (CSA), maximal voluntary isometric contraction (MVIC) at 30o and 90o of knee flexion and 1RM performance were assessed before and after the training period. In addition, normalized EMG amplitude-angle and force-angle relationships were assessed in the 6th and 39th experimental sessions. Results The 6-s RD protocol induced larger gains in MVIC at 30o of knee angle measurement than the 2-s RD protocol. Increases in MVIC at 90o of knee angle, 1RM, rectus femoris and vastus lateralis CSA were not significant between the 2-s and 6-s RD protocols. Moreover, different normalized EMG amplitude-angle and force-angle values were detected between protocols over most of the angles analyzed. Conclusion Performing longer RD could be a more appropriate strategy to provide greater gains in isometric maximal muscle strength at shortened knee positions. However, similar maximum dynamic strength and muscle hypertrophy gains would be provided by protocols with different RD.


2008 ◽  
Vol 104 (5) ◽  
pp. 1320-1328 ◽  
Author(s):  
Taija Finni ◽  
Marko Havu ◽  
Shantanu Sinha ◽  
Jussi-Pekka Usenius ◽  
Sulin Cheng

We examined the relationships between morphology and muscle-tendon dynamics of the quadriceps femoris muscle of 11 men using velocity-encoded phase-contrast magnetic resonance imaging (MRI). Thigh muscle electromyography and joint range of motion were first measured outside the MRI scanner during knee extension-flexion tasks that were performed at a rate of 40 times/min with elastic bands providing peak resistance of 5.2 kp (SD 0.4) to the extension. The same movement was repeated inside the MRI scanner bore where tissue velocities and muscle morphology were recorded. The average displacement in the proximal and distal halves of the rectus femoris and vastus intermedius aponeuroses was different ( P = 0.049), reflecting shortening (1.6%), but the tensile strain along the length of the aponeuroses was uniform. The aponeurosis behavior varied among individuals, and these individual patterns were best explained by the differences in relative cross-sectional area of rectus femoris to vastus muscles ( r = 0.71, P = 0.014). During dynamic contraction, considerable deformation of muscles in the axial plane caused an anatomic measure such as muscle thickness to change differently (decrease or increase) in different sites of measurement. For example, when analyzed from the axial images, the vastus lateralis thickness did not change ( P = 0.946) in the frontal plane through femur but increased in a 45° oblique plane between the frontal and sagittal planes ( P = 0.004). The present observations of the heterogeneity and individual behavior emphasize the fact that single-point measurements do not always reflect the overall behavior of muscle-tendon unit.


Author(s):  
Giuseppe Coratella ◽  
Gianpaolo Tornatore ◽  
Francesca Caccavale ◽  
Stefano Longo ◽  
Fabio Esposito ◽  
...  

The present study investigated the activation of gluteal, thigh, and lower back muscles in different squat variations. Ten male competitive bodybuilders perform back-squat at full (full-BS) or parallel (parallel-BS) depth, using large feet-stance (sumo-BS), and enhancing the feet external rotation (external-rotated-sumo-BS) and front-squat (FS) at 80% 1-RM. The normalized surface electromyographic root-mean-square (sEMG RMS) amplitude of gluteus maximus, gluteus medius, rectus femoris, vastus lateralis, vastus medialis, adductor longus, longissimus, and iliocostalis was recorded during both the ascending and descending phase of each exercise. During the descending phase, greater sEMG RMS amplitude of gluteus maximus and gluteus medius was found in FS vs. all other exercises (p < 0.05). Additionally, FS elicited iliocostalis more than all other exercises. During the ascending phase, both sumo-BS and external-rotated-sumo-BS showed greater vastus lateralis and adductor longus activation compared to all other exercises (p < 0.05). Moreover, rectus femoris activation was greater in FS compared to full-BS (p < 0.05). No between-exercise difference was found in vastus medialis and longissimus showed no between-exercise difference. FS needs more backward stabilization during the descending phase. Larger feet-stance increases thigh muscles activity, possibly because of their longer length. These findings show how bodybuilders uniquely recruit muscles when performing different squat variations.


2021 ◽  
Vol 30 (3) ◽  
pp. 387-395
Author(s):  
Soojin Kim ◽  
Joo-Hyun Lee ◽  
Jihye Heo ◽  
Eunwook Chang

PURPOSE: The purpose of this study was to compare thigh muscle activities and muscle co-activation when performing squats, wall squats, and Spanish squats on stable and unstable ground.METHODS: Twenty-two healthy male subjects (age: 22.50±2.70 years, height: 178.72±6.04 cm, mass: 76.50±6.80 kg, body mass index: 24.00±2.10 kg/m2, and Godin activity questionnaire: 56.30±24.10) voluntarily participated in the study. All of the participants performed three different squat exercises on the floor and the BOSU ball with an electromyograph attached to each participant’s quadriceps (rectus femoris, RF; vastus lateralis, VL; and vastus medialis, VM) and hamstrings (biceps femoris, BF; semitendinosus, ST; and semimembranosus, SM). Repeated measures of analysis of variance were utilized to compare muscle activity during the three squats exercises by floor type.RESULTS: RF (p<.001, η2=.689), VL (p<.001, η2=.622), and VM (p=.002, η2=.375) showed significant differences between exercises. Spanish squats yielded greater BF activity than did wall squats (p=.018, η2=.269). ST yielded greater muscle activity with the BOSU ball than on the floor (p=.018, η2=.269). Finally, there was a significant ground exercise interaction effect on the co-activation, showing greater muscle co-activation with Spanish squats on the BOSU ball compared to squats, squats on the BOSU ball, and wall squat on the BOSU ball.CONCLUSIONS: The findings of this study indicate that Spanish squats could be an effective exercise option for the facilitation of RF, VL, VM, and BF muscle activation. In particular, performing Spanish squats on an unstable surface could be useful for patients who need to improve their quadriceps muscle activation.


2014 ◽  
Vol 41 (1) ◽  
pp. 23-32
Author(s):  
Patrícia Dias Pantoja ◽  
André Mello ◽  
Giane Veiga Liedtke ◽  
Ana Carolina Kanitz ◽  
Eduardo Lusa Cadore ◽  
...  

AbstractThis study aimed to describe the neuromuscular activity of elite athletes who performed various roller figure skating jumps, to determine whether the muscle activation is greater during jumps with more rotations and in which phase the muscles are more active. This study also aimed to analyze if there is any difference in the muscle activity pattern between female and male skaters. Four elite skaters were evaluated, and each participated in two experimental sessions. During the first session, anthropometric data were collected, and the consent forms were signed. For the second session, neuromuscular data were collected during jumps, which were performed with skates at a rink. The following four roller figure skating jumps were evaluated: single Axel, double Axel, double Mapes and triple Mapes. The neuromuscular activity of the following seven muscles was obtained with an electromyograph which was fixed to the waist of each skater with a strap: biceps femoris, lateral gastrocnemius, tibialis anterior, rectus femoris, vastus lateralis, vastus medialis and gluteus maximus. The signal was transmitted wirelessly to a laptop. During the roller figure skating jumps, the lateral gastrocnemius, rectus femoris, vastus lateralis, biceps femoris and gluteus maximus, showed more activation during the jumps with more rotations, and the activation mainly occurred during the propulsion and flight phases. Female skaters demonstrated higher muscle activities in tibialis anterior, vastus lateralis, vastus medialis and gluteus maximus during the landing phase of the triple Mapes, when compared to their male counterparts. The results obtained in this study should be considered when planning training programs with specific exercises that closely resemble the roller figure skating jumps. This may be important for the success of elite skaters in competitions.


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