scholarly journals Different changes of muscle hardness between the rectus femoris and vastus intermedius muscle after maximal knee extension exercise

2021 ◽  
Vol 70 (5) ◽  
pp. 293-305
Author(s):  
Mika Inoue ◽  
Atsushi Kubota ◽  
Kohei Kishimoto ◽  
Hirofumi Nishio ◽  
Yuji Takazawa
Keyword(s):  
Rectus Femoris ◽  
Knee Extension ◽  
Muscle Hardness ◽  
Vastus Intermedius ◽  
Knee Extension Exercise

Can Hip Joint Position affect Quadriceps Muscle Responses during Knee Extension Exercise?

2020 ◽  
Vol 41 (13) ◽  
pp. 929-935
Author(s):  
Denis César Leite Vieira ◽  
Marco Aurélio Araujo Dourado ◽  
Lucas Ugliara ◽  
Joao Luiz Quagliotti Durigan ◽  
Brad J. Schoenfeld ◽  
...  
Keyword(s):  
Vastus Lateralis ◽  
Muscle Thickness ◽  
Rectus Femoris ◽  
Peak Torque ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Knee Extensors ◽  
Work Output ◽  
Before And After ◽  
Knee Extension Exercise

AbstractThis study investigated the acute effects of seated and supine knee extension exercise on muscle swelling, torque, and work output. Twelve resistance-trained men performed two isokinetic concentric-only knee-extension training protocols at different hip positions in a counter-balanced order. They completed the knee extension exercise in the seated (hip angle at 85°) and supine (hip angle at 180°) positions. The torque and work output were assessed during each set. Moreover, muscle thickness of the middle and proximal vastus lateralis and rectus femoris were evaluated before and after each protocol and used as an indicator of muscle swelling. Middle rectus femoris and proximal vastus lateralis thickness increased significantly (p=0.01) with no difference between exercise variations. However, the middle vastus lateralis thickness increased (p=0.01) only after the seated knee extension exercise (~7%). Knee extensors’ peak torque and work output were approximately 8% higher (p=0.04) in the seated when compared to the supine hip position. There was a similar decrease in torque and work output throughout both protocols (p=0.98). In conclusion, seated knee extension exercises produced greater torque, work output, and muscle swelling in the vastus lateralis when compared to the supine knee extension exercise.

scholarly journals Comparison of quadriceps muscle activation in exercises with different duration of concentric and eccentric contractions

2020 ◽  
Vol 37 (5) ◽  
pp. 291-297
Author(s):  
G Freire da Silva ◽  
F Douglas Tourino ◽  
RC Ribeiro Diniz ◽  
L Túlio de Lacerda ◽  
HC Martins Costa ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Knee Extensor ◽  
Rectus Femoris ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Muscle Action ◽  
Emg Signal ◽  
Knee Extension Exercise

Aim: The objective of the present study was to compare the amplitude of the electromyographic (EMG) signal of the quadriceps muscle portions vastus medialis (VM), vastus lateralis (VL) and rectus femoris (RF) and the activation ratio (VM/VL, VM/RF and VL/RF) in protocols with different durations of concentric and eccentric muscular actions. Material and method: Twelve female volunteers performed the knee extensor exercise with two different protocols [1s for concentric muscle action and 5s for eccentric muscle action (1:5); 5s of concentric muscle action and 1s of eccentric muscle action (5:1)] and 3 sets of 6 repetitions, 180s of pause between each sets and a intensity of 50% of 1RM. The root mean square of the amplitude of the normalized EMG signal was calculated for each repetition in each series. Results: it was observed an increase in the activation of the VM and VL portions in equivalent repetitions of each series and for the VL portion, the 1: 5 protocol provided greater activation compared to the other protocol. No differences were found for muscles activation ratios VM/RF and VL/RF, being that for the VM/VL ratio there was only change at one repetition. Conclusion: The results suggest that the portions of the quadriceps muscle may present different EMG responses in similar protocols, but this fact may not interfere in the synergism between them. The reduced degrees of freedom of the knee extension exercise and the characteristics of the protocols adopted may be the elements that contributed to the limited alterations that occurred in the present study.

scholarly journals Neuromuscular efficiency of the knee joint muscles in the early-phase of strength training: effects of antagonist’s muscles pre-activation

Motricidade ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 24-32
Author(s):  
Euler Alves Cardoso ◽  
Frederico Ribeiro Neto ◽  
Wagner Rodrigues Martins ◽  
Martim Bottaro ◽  
Rodrigo Luiz Carregaro
Keyword(s):  
Knee Flexion ◽  
Controlled Trial ◽  
Rectus Femoris ◽  
Training Group ◽  
Knee Extension ◽  
Effect Sizes ◽  
Randomized Controlled ◽  
Knee Extension Exercise ◽  
Rectus Femoris Muscle ◽  
Femoris Muscle

It was our objective tTo compare the neuromuscular efficiency (NME) adaptations between resistance exercise methods (with and without pre-activation of the antagonist’s muscles) after six-weeks training. This randomized controlled trial assigned forty-nine men (mean age 20.9 ± 2.2 years; height 1.80 ± 0.1 m; body mass 75.0 ± 8.2 kg) into two groups: 1) Reciprocal Training group (RT, concentric knee flexion immediately followed by concentric knee extension at 60°.s-1); and Conventional Training (CT, concentric knee extension exercise). Both training adopted three sets, 10 repetitions at 60°.s-1, 2 days/week for 6 weeks. NME of knee extension and flexion were assessed pre and post-training. The groups were similar at baseline, for all variables. We found significant effects on NME only for the rectus femoris muscle in the RT group (ES = 0.31; 95%CI [0.30-0,92]; p<0.01). There were no significant differences at NME pre- and post-training in CT and Total Work did not differ between groups. Reciprocal training provided better neuromuscular efficiency, but effects were limited to the rectus femoris muscle. The small effect sizes suggest caution in the results.

Assessment of central aponeurosis curvature as an index of rectus femoris muscle overstrain in individuals with knee osteoarthritis

2021 ◽  
pp. 1-6
Author(s):  
Yusuke Takahashi ◽  
Kazuki Okura ◽  
Kazuo Kinoshita ◽  
Arata Seto ◽  
Akira Saito ◽  
...  
Keyword(s):  
Knee Osteoarthritis ◽  
Structural Changes ◽  
Rectus Femoris ◽  
The Elderly ◽  
Knee Extension ◽  
Elderly Group ◽  
Knee Oa ◽  
Vastus Intermedius ◽  
Osteoarthritis Knee ◽  
Grade Ii

BACKGROUND: In medial knee osteoarthritis (knee OA), compensatory overstrain of the rectus femoris (RF) muscle leads to its hypertrophy. We hypothesize that besides hypertrophy of the RF, a prominent flattening of the central aponeurosis (CA) curvature is also indicative of RF. This study aims to evaluate the structural changes in the CA and clarify the conditions associated with RF overstrain in knee OA. OBJECTIVE: Twenty-three legs of 20 elderly without knee OA (elderly group) and 26 legs of 20 individuals with K-L grade II knee OA (knee OA group) with typical “comma”-shaped CA participated in this study. METHODS: The knee extension torque (Nm/kg) in the sitting position, the thickness of the RF and vastus intermedius (VI) muscles (VI), and change in CA curvature (%Curvature) were measured at the mid-thigh by ultrasonography. RESULTS: The knee extension torque was not significantly different between the two groups. Compared to the elderly group, the knee OA group had significantly thicker RF at rest, while the VI thickness during contraction was significantly smaller. The %Curvature was significantly higher in the knee OA group than in the elderly group. CONCLUSIONS: In the knee OA group, the RF was hypertrophic with a more pronounced CA flattening during muscle contraction, although the other quadriceps muscles were atrophic, suggesting an overstrained RF. Assessing thickness and CA curvature of the RF is, therefore, useful and simple for evaluating overstrain caused by RF compensation.

scholarly journals Effect of position and exercise on measurement of muscle quantity and quality: towards a standardised pragmatic protocol for clinical practice

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Carly Welch ◽  
Zeinab Majid ◽  
Isabelle Andrews ◽  
Zaki Hassan-Smith ◽  
Vicky Kamwa ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Skeletal Muscle Mass ◽  
Rectus Femoris ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Upper Body ◽  
Fat Percentage ◽  
Non Invasive ◽  
Vastus Intermedius ◽  
Total Body

Abstract Background Ultrasonography is an emerging non-invasive bedside tool for muscle quantity/quality assessment; Bioelectrical Impedance Analysis (BIA) is an alternative non-invasive bedside measure of body composition, recommended for evaluation of sarcopenia in clinical practice. We set out to assess impact of position and exercise upon measures towards protocol standardisation. Methods Healthy volunteers aged 18–35 were recruited. Bilateral Anterior Thigh Thickness (BATT; rectus femoris and vastus intermedius), BATT: Subcutaneous Ratio (BATT:SCR), and rectus femoris echogenicity were measured using ultrasound and BIA was performed; 1) lying with upper body at 45° (Reclined), 2) lying fully supine at 180o (Supine), 3) sat in a chair with upper body at 90o (Sitting), and 4) after exercise Reclined. Variability of Skeletal Muscle Mass (SMM) by two different equations from BIA (SMM-Janssen, SMM-Sergi), phase angle, fat percentage, and total body (TBW), extracellular (ECW), and intracellular water (ICW) were assessed. Results Forty-four participants (52% female; mean 25.7 years-old (SD 5.0)) were recruited. BATT increased from Reclined to Sitting (+ 1.45 cm, 1.27–1.63), and after exercise (+ 0.51, 0.29–0.73). Echogenicity reduced from Reclined to Sitting (− 2.1, − 3.9 – -0.26). SMM-Sergi declined from Reclined to Supine (− 0.65 kg, − 1.08 – − 0.23) and after exercise (− 0.70 kg, − 1.27 – -0.14). ECW increased from Reclined to Sitting (+ 1.19 L, 0.04–2.35). There were no other statistically significant changes. Conclusion Standardisation of protocols is especially important for assessment of muscle quantity by ultrasonography; BIA measurements may also vary dependent on the equations used. Where possible, participants should be rested prior to muscle ultrasonography and BIA, and flexion of the knees should be avoided.

Changes in muscle activities and kinematics due to simulated leg length inequalities

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hannah Lena Siebers ◽  
Jörg Eschweiler ◽  
Filippo Migliorini ◽  
Valentin Michael Quack ◽  
Markus Tingart ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Pelvic Obliquity ◽  
Lateral Flexion ◽  
Leg Length ◽  
Joint Angles ◽  
Leg Muscles ◽  
Compensation Mechanisms ◽  
Musculoskeletal Problems

Abstract Muscle imbalances are a leading cause of musculoskeletal problems. One example are leg length inequalities (LLIs). This study aimed to analyze the effect of different (simulated) LLIs on back and leg muscles in combination with kinematic compensation mechanics. Therefore, 20 healthy volunteers were analyzed during walking with artificial LLIs (0–4 cm). The effect of different amounts of LLIs and significant differences to the reference condition without LLI were calculated of maximal joint angles, mean muscle activity, and its symmetry index. While walking, LLIs led to higher muscle activity and asymmetry of back muscles, by increased lumbar lateral flexion and pelvic obliquity. The rectus femoris showed higher values, independent of the amount of LLI, whereas the activity of the gastrocnemius on the shorter leg increased. The hip and knee flexion of the long leg increased significantly with increasing LLIs, like the knee extension and the ankle plantarflexion of the shorter leg. The described compensation mechanisms are explained by a dynamic lengthening of the short and shortening of the longer leg, which is associated with increased and asymmetrical muscle activity. Presenting this overview is important for a better understanding of the effects of LLIs to improve diagnostic and therapy in the future.

scholarly journals POS0832 A NOVEL GREY SCALE AND POWER DOPPLER ULTRASONOGRAPHIC SCORE FOR IDIOPATHIC INFLAMMATORY MYOPATHIES: SIENA MYOSITIS ULTRASOUND GRADING SCALE

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 669.1-670
Author(s):  
E. Conticini ◽  
P. Falsetti ◽  
S. G. Al Khayyat ◽  
C. Baldi ◽  
F. Bellisai ◽  
...  
Keyword(s):  
Disease Duration ◽  
Muscle Fibers ◽  
Power Doppler ◽  
Muscle Thickness ◽  
Rectus Femoris ◽  
Normal Muscle ◽  
Small Vessels ◽  
Grey Scale ◽  
Vastus Intermedius ◽  
Grading Scale

Background:No clear-cut guidelines exist about the use of diagnostic procedures for idiopathic inflammatory myopathies (IIM) and only scanty and conflicting data report the use of ultrasound (US).Objectives:We aimed to assess if grey-scale (GS) and Power Doppler (PD) US, graded with a 0-3-points-scale, may be a reliable tool in a cohort of patients affected by IIM.Methods:We prospectively collected, since July to October 2020, all patients referred to Vasculitis and Myositis clinic, Rheumatology Unit, University of Siena, for suspected IIM, as well as patients with a previous, definite diagnosis of IIM and evaluated during follow-up or referred from other centers for a second opinion. All patients underwent US examination of both thighs in axial and longitudinal scans. Edema and atrophy, both assessed in GS, and PD, were graded with a 0-3-points-scale. Spearman test was used to identify the correlations between US and clinical and serological variables.Results:A total of 18 patients was included. Four of them were evaluated twice, at baseline and within 3 months of therapy. Muscle edema was found to be directly correlated with physician global assessment (PhGA), serum myoglobin and PD and negatively with disease duration. PD score was positively correlated to PhGA and negatively to disease duration. Muscle atrophy directly correlated with Myositis Damage Index and patients’ age. The single-thigh sub-analysis evidenced a direct correlation between PD score and Manual Muscle Test.Conclusion:In our cohort, we found that edema and PD are strictly related to early, active myositis, suggesting that an inflamed muscle should appear swollen, thickened and with Doppler signal. Conversely, muscle atrophy reflects the age of the patient and the overall severity of the disease. Such findings shed a new, promising, light in the role of US in diagnosis and monitoring of IIMs.Table 1.Siena Myositis Ultrasound Grading Scale (SMUGS).Grey-scale edemaGrey-scale atrophyPower Doppler0Normal muscle echotexture with hyperechoic septa and hypoechoic muscle fibers, conserved thickness.Normal muscle echotexture, with hyperechoic septa and hypoechoic muscle fibers, conserved thickness.No PD signal.1Focal hypoechoic areas, where septa are less evident. Conserved thickness.Focal heterogeneously hyperechoic areas, where septa are thicker and more evident, and muscle fibers are thinner. Conserved muscle thickness.One or two PD signals in at least one muscle (PD vascular spots, small vessels of homogenous diameters, vessel diameters approximately not superior to fibrous intramuscular septa)2Diffuse and heterogeneous hypo echogenicity (rectus femoris as hypoechoic or more than vastus intermedius), septa diffusely less evident. Conserved thickness.Diffuse and heterogeneously hyperechoic muscle, with thicker septa and thinner muscle fibers. Conserved muscle thickness.More than 2 PD signals for each muscle (as vascular spots, small vessels of homogenous diameters, vessel diameters approximately not superior to fibrous intramuscular septa).3Diffuse and heterogeneous hypo echogenicity (rectus femoris as hypoechoic or more than vastus intermedius), septa diffusely less evident. Increased thickness (rectus femoris became thicker than vastus intermedius).Diffuse and heterogeneously hyperechoic muscle, with thicker septa and thinner muscle fibers. Reduced muscle thickness.More than 2 PD signals for each muscle with larger diameter of the vessel (at least superior to fibrous intramuscular septa), or vessels with different diameters or branched vessels.Figure 1.Different PD findings (clockwise) in longitudinal anterior scans of the thigh: PD 3 in a patient with a recent diagnosis of anti-Mi2 DM; PD 2 in the same patient after one month of treatment with steroids and Methotrexate; PD 1 in a patient affected by anti-SAE DM, with a suspected disease flare; PD 0 in a patient affected by an advanced polymyositis diagnosed in 2000, currently not in treatment.Disclosure of Interests:None declared

scholarly journals Passive knee exoskeletons in functional tasks: Biomechanical effects of a SpringExo coil-spring on squats

2021 ◽  
Vol 2 ◽  
Author(s):  
Rand Hidayah ◽  
Dongbao Sui ◽  
Kennedi A. Wade ◽  
Biing-Chwen Chang ◽  
Sunil Agrawal
Keyword(s):  
Outcome Measures ◽  
Muscle Activation ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Lower Limbs ◽  
Flexion Angle ◽  
Coil Spring ◽  
Foot Pressure ◽  
Low Profile ◽  
Muscle Activations

Abstract Passive wearable exoskeletons are desirable as they can provide assistance during user movements while still maintaining a simple and low-profile design. These can be useful in industrial tasks where an ergonomic device could aid in load lifting without inconveniencing them and reducing fatigue and stress in the lower limbs. The SpringExo is a coil-spring design that aids in knee extension. In this paper, we describe the muscle activation of the knee flexors and extensors from seven healthy participants during repeated squats. The outcome measures are the timings of the key events during squat, flexion angle, muscle activation of rectus femoris and bicep femoris, and foot pressure characteristics of the participants. These outcome measures assess the possible effects of the device during lifting operations where reduced effort in the muscles is desired during ascent phase of the squat, without changing the knee and foot kinematics. The results show that the SpringExo significantly decreased rectus femoris activation during ascent (−2%) without significantly affecting either the bicep femoris or rectus femoris muscle activations in descent. This implies that the user could perform a descent without added effort and ascent with reduced effort. The exoskeleton showed other effects on the biomechanics of the user, increasing average squat time (+0.02 s) and maximum squat time (+0.1 s), and decreasing average knee flexion angle (−4°). The exoskeleton has no effect on foot loading or placement, that is, the user did not have to revise their stance while using the device.

Effects of a prior high-intensity knee-extension exercise on muscle recruitment and energy cost: a combined local and global investigation in humans

2009 ◽  
Vol 94 (6) ◽  
pp. 704-719 ◽  
Author(s):  
Gwenael Layec ◽  
Aurélien Bringard ◽  
Yann Le Fur ◽  
Christophe Vilmen ◽  
Jean-Paul Micallef ◽  
...  
Keyword(s):  
Energy Cost ◽  
High Intensity ◽  
Knee Extension ◽  
Muscle Recruitment ◽  
Knee Extension Exercise

Prior heavy knee extension exercise does not affect $$\dot{V}\hbox{O}_{2}$$ kinetics during subsequent heavy cycling exercise

2007 ◽  
Vol 102 (4) ◽  
pp. 481-491 ◽  
Author(s):  
John R. Thistlethwaite ◽  
Benjamin C. Thompson ◽  
Joaquin U. Gonzales ◽  
Barry W. Scheuermann
Keyword(s):  
Knee Extension ◽  
Cycling Exercise ◽  
Knee Extension Exercise
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