Imaging Assessment of Nontraumatic Pathologic Conditions at the Craniovertebral Junction: A Comprehensive Review.

Nontraumatic pathologic conditions of the craniovertebral junction encompass a range of conditions affecting the complex anatomy of this region without direct physical injury. These conditions include congenital syndromes that predispose individuals to ligamentous laxity, potentially leading to instability. Additionally, rare but noteworthy cases such as Grisel syndrome, a cause of pediatric torticollis, may arise without a traumatic trigger. Inflammatory diseases, including rheumatoid arthritis, ankylosing spondylitis, and crystal deposition, can lead to cervical instability and spinal cord compression. Infections at the upper cervical spine are dominated by tuberculosis, typically transmitted through hematologic or lymphatic routes with characteristic imaging findings. On the other hand, purulent bacterial infections in this area are rare. Furthermore, although tumors involving the structures of the craniovertebral junction are infrequent, they can lead to significant complications, albeit less frequently through cord compression and more commonly via pathologic fractures or subluxation. The craniocervical junction is a complex anatomic region comprising ligaments, bones, joints, and muscles that support the head's weight and enable its wide range of motion. Accurate recognition and understanding of the complex anatomy and the various nontraumatic pathologic conditions at the craniovertebral junction are pivotal for initiating timely and appropriate treatment strategies. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Higher resistance training volume offsets muscle hypertrophy nonresponsiveness in older individuals.

The magnitude of muscle hypertrophy in response to resistance training (RT) is highly variable between individuals (response heterogeneity). Manipulations in RT variables may modulate RT-related response heterogeneity; yet, this remains to be determined. Using a within-subject unilateral design, we aimed to investigate the effects of RT volume manipulation on whole muscle hypertrophy [quadriceps muscle cross-sectional area (qCSA)] among nonresponders and responders to a low RT dose (single-set). We also investigated the effects of RT volume manipulation on muscle strength in these responsiveness groups. Eighty-five older individuals [41M/44F, age = 68 ± 4 yr; body mass index (BMI) = 26.4 ± 3.7 kg/m2] had one leg randomly allocated to a single (1)-set and the contralateral leg allocated to four sets of unilateral knee-extension RT at 8-15 repetition maximum (RM) for 10-wk 2 days/wk. Pre- and postintervention, participants underwent magnetic resonance imaging (MRI) and unilateral knee-extension 1-RM strength testing. MRI typical error (2× TE = 3.27%) was used to classify individuals according to responsiveness patterns. n = 51 were classified as nonresponders (≤2× TE) and n = 34 as responders (>2× TE) based on pre- to postintervention change qCSA following the single-set RT protocol. Nonresponders to single-set training showed a dose response, with significant time × set interactions for qCSA and 1-RM strength, indicating greater gains in response to the higher volume prescription (time × set: P < 0.05 for both outcomes). Responders improved qCSA (time: P < 0.001), with a tendency toward higher benefit from the four sets RT protocol (time × set: P = 0.08); on the other hand, 1-RM increased similarly irrespectively of RT volume prescription (time × set: P > 0.05). Our findings support the use of higher RT volume to mitigate nonresponsiveness among older adults.NEW & NOTEWORTHY Using a within-subject unilateral design, we demonstrated that increasing resistance training (RT) volume may be a simple, effective strategy to improve muscle hypertrophy and strength gains among older adults who do not respond to low-volume RT. In addition, it could most likely be used to further improve hypertrophic outcomes in responders.

Effect of different training frequencies on maximal strength performance and muscle hypertrophy in trained individuals-a within-subject design.

Several studies comparing resistance training (RT) frequencies may have been affected by the large between-subject variability. This study aimed to compare the changes in lower limbs maximal dynamic strength (1RM) and quadriceps femoris cross-sectional area (CSA) after a RT with different weekly frequencies in strength-trained individuals using a within-subject design. Twenty-four men participated in a 9-week RT program, being randomly divided into two conditions: resistance training with equalized total training volume (RTEV) and with unequalized total training volume (RTUV). The RT protocol used the unilateral leg press 45° exercise and each subject's lower limb executed one of the proposed frequencies (one and three times/week). All conditions effectively increased 1RM and CSA (p<0.001); however, no significant differences were observed in the values of 1RM (p = 0.454) and CSA (p = 0.310) between the RT frequencies in the RTEV and RTUV conditions. Therefore, RT performed three times a week showed similar increases in 1RM and CSA to the program performed once a week, regardless of training volume equalization. Nevertheless, when the higher RT frequency allowed the application of a greater TTV (i.e., RTUV), higher effect size (ES) values (0.51 and 0.63, 1RM and CSA, respectively) were observed for the adaptations.

Daily Leucine Intake Is Positively Associated with Lower Limb Skeletal Muscle Mass and Strength in the Elderly.

Higher daily protein intake, with an emphasis on leucine content, is thought to mitigate age-related anabolic resistance, potentially counteracting age-related morphological and functional declines. The present study investigated potential associations between total daily leucine intake and dependent variables, including quadriceps muscle cross-sectional area (CSA) and maximum dynamic muscle strength (1-RM) in a cohort of healthy free-living older individuals of both sexes (n = 67; 34/33 men/women). Participants performed three 24 h dietary recalls and underwent a magnetic resonance imaging exam followed by 1-RM tests. Our results demonstrate moderate associations between total daily leucine and both quadriceps CSA (r = 0.42; p = 0.004) and 1-RM (r = 0.45; p = 0.001). Furthermore, our exploratory biphasic linear regression analyses, adjusted for sex, age, and protein intake relative to body weight, revealed a plateau for daily leucine intake and muscle mass and muscle strength (~7.6-8.0 g·day-1) in older adults. In conclusion, we demonstrated that total daily leucine intake is associated with muscle mass and strength in healthy older individuals and this association remains after controlling for multiple factors, including overall protein intake. Furthermore, our breakpoint analysis revealed non-linearities and a potential threshold for habitual leucine intake, which may help guide future research on the effects of chronic leucine intake in age-related muscle loss.

Differential Diagnosis of Facet Joint Disorders.

Spinal pain due to facet joint disease is difficult to diagnose since the clinical history and physical examination findings are usually nonspecific. Facet joint disorders have a wide range of causes and, because of the potential for chronic back pain and disability, an accurate diagnosis is essential. The most frequent cause of pain in facet joints is osteoarthritis, which can be assessed at radiography, CT, or MRI. Ganglion and synovial cysts of the facet joints can cause compressive symptoms of adjacent structures, especially radiculopathy, lower back pain, and sensory or motor deficits. In ankylosing spondylitis, imaging findings of the facet joints are useful not only for diagnosis but also for monitoring structural changes. In septic arthritis of the facet joints, an early diagnosis at MRI is essential. Gout and metabolic diseases are best evaluated at dual-energy CT, which allows the depiction of crystals. Traumatic dislocations of facet joints are usually unstable injuries that require internal reduction, fixation, and fusion and can be well assessed at CT with three-dimensional reconstructions. Facet joint neoplasms like osteoid osteoma, plasmacytoma, tenosynovial giant cell tumor, and osteochondroma are best evaluated at CT or MRI. The authors provide an overview of key imaging features of the most common facet joint disorders along with anatomic tips and illustrative cases. Acknowledging key imaging findings for the differential diagnosis of facet joint disorders plays a crucial role in the diagnostic accuracy and proper treatment approach for such entities. Online supplemental material is available for this article. ©RSNA, 2021.

Blood Flow Restriction Does Not Attenuate Short-Term Detraining-Induced Muscle Size and Strength Losses After Resistance Training With Blood Flow Restriction.

ABSTRACT: Teixeira, EL, de Salles Painelli, V, Silva-Batista, C, de Souza Barros, T, Longo, AR, Lasevicius, T, Schoenfeld, BJ, Aihara, AY, and de Almeida Peres, B. Blood flow restriction does not attenuate short-term detraining-induced muscle size and strength losses after resistance training with blood flow restriction. J Strength Cond Res 35(8): 2082-2088, 2021-After a short-term resistance training with blood flow restriction (BFR), we investigated the effects of 12 days of detraining (DET), without an exercise stimulus, on quadriceps cross-sectional area (QCSA) and muscle strength (1 repetition maximum [1RM]), with 1 leg receiving daily intermittent BFR during DET vs. the same nonexercise condition without BFR (CON) in the contralateral leg. Both subjects' legs were evaluated for QCSA and 1RM before (PRE) and after (POST) both legs being unilaterally submitted to 3 weeks (4 days per week) of low-load (3 sets of 15 repetitions, 30% 1RM) resistance training with BFR. The DET period started immediately after POST, where each leg was randomly submitted to a daily intermittent BFR protocol or CON, without any associated exercise stimulus. Quadriceps cross-sectional area and 1RM were reassessed after DET. Both legs at CON and BFR conditions increased QCSA (6.3 and 6.8%, respectively; both p < 0.0001) and 1RM (9.5 and 10.1%, respectively; both p < 0.05) from PRE to POST. Both legs at CON and BFR conditions reduced QCSA (-4.6 and 4.9%, respectively; both p < 0.0001) and 1RM (-9.0 and -8.2%, respectively; both p < 0.05) from POST to DET, with no significant differences between conditions (p > 0.05). We conclude that muscle strength and hypertrophy gains obtained in 3 weeks of resistance training with BFR are not maintained after 12 days of DET. Moreover, the application of BFR, without an associated exercise stimulus, does not attenuate such losses.

Pseudarthrosis in anterior cervical discectomy and fusion with a self-locking, stand-alone cage filled with hydroxyapatite: a retrospective study with clinical and radiological outcomes of 98 levels with a minimum 2-year follow-up.

OBJECTIVE: The goal of this study was to evaluate the incidence of pseudarthrosis after the treatment of cervical degenerative disc disease (CDDD) with anterior cervical discectomy and fusion (ACDF) in which self-locking, stand-alone intervertebral cages filled with hydroxyapatite were used. METHODS: The authors performed a retrospective cohort study of 49 patients who underwent 1- to 3-level ACDF with self-locking, stand-alone intervertebral cages without plates, with a minimum 2 years of follow-up. The following data were extracted from radiological and clinical charts: age, sex, time and type of pre- and postoperative signs and symptoms, pain status (visual analog scale [VAS]), functional status (Neck Disability Index [NDI]), history of smoking, bone quality (bone densitometry), and complications. Pseudarthrosis was diagnosed by a blinded neuroradiologist using CT scans. Clinical improvement was assessed using pre- and postoperative comparison of VAS and NDI scores. The Wilcoxon test for paired tests was used to evaluate statistical significance using a p value of < 0.05. RESULTS: Three patients (6%) developed symptomatic pseudarthrosis requiring reoperation, with only 1 patient showing clinical worsening due to pseudarthrosis, while the other 2 with pseudarthrosis had associated disc disease at an adjacent level. The rate of symptomatic pseudarthrosis according to the number of operated levels was 0% for 1 level, 8.7% (2/23 patients) for 2 levels, and 7.7% (1/13 patients) for 3 levels. The total pseudarthrosis rate (including both symptomatic and asymptomatic patients) was 16.4%. Considering the clinical outcomes, there was a significant improvement of 75.6% in neck pain and 95.7% in arm pain, as well as a 64.9% improvement in NDI scores. Complications were observed in 18.4% of patients, with adjacent-level degenerative disease being the most prevalent at 14.3%. CONCLUSIONS: ACDF with self-locking, stand-alone cages filled with a hydroxyapatite graft can be used for the surgical treatment of 1- to 3-level CDDD with clinical and radiological outcomes significantly improved after a minimum 2-year follow-up period. Comparative studies are necessary.

The development of the intercondylar notch in the pediatric population.

BACKGROUND: Anterior cruciate ligament (ACL) repair is increasing in frequency in younger children. Recognition of the normal development of the intercondylar notch is important for successful ACL graft placement, allowing surgeons to better understand the anatomy and risk factors related to ACL tears and its reconstruction. The purpose of this study was to compile normative data on the intercondylar notch in the pediatric population with magnetic resonance imaging (MRI), emphasizing the differences between males and females. METHODS: In this retrospective study, musculoskeletal radiologists evaluated intercondylar notch width, bicondylar distance and notch width index (NWI). A total of 253 MRI examinations (130 males and 123 females between six and 18 years of age) were included. The association between measurements, sex and age was considered. Linear and fractional polynomial regression models were used to evaluate the relationships between measurements. RESULTS: Intercondylar notch width increased up to 10 years of age in females and 11 years of age in males, with relative stabilization up to 13 years in girls and 14 years in boys and a slight reduction in values at subsequent ages. Bicondylar distance showed significant progressive growth with age in both sexes. NWI showed a discrete and homogenous reduction with age in both sexes. CONCLUSION: Intercondylar notch width interrupts its growth around 10-11 years of age, with relative stabilization up to 13-14 years and a slight reduction in dimensions in subsequent ages. This growth pattern resembles the development of the ACL area observed in recent studies.

Radiological findings of fibrocartilaginous coalition of the third tarsometatarsal joint: a retrospective cross-sectional study with computed tomography and magnetic resonance imaging.

BACKGROUND: Fibrocartilaginous coalition of the third tarsometatarsal joint has been indicated as an extremely rare form of tarsal coalition in the radiological literature, and most articles concerned with tarsal coalition do not mention involvement of this joint. Only two reports written in the English language that approach this subject were found, an orthopedic report and an anthropological report. PURPOSE: To evaluate the prevalence of this finding and discuss and illustrate the radiological characteristics of this coalition. MATERIAL AND METHODS: A retrospective analysis of 614 computed tomography or magnetic resonance imaging scans of the ankle and/or foot, acquired at a health service within a period of three months, was performed to assess the prevalence of this coalition. RESULTS: Of the examinations characterized as valid for analysis for the purposes of the study, 17 cases compatible with fibrocartilaginous coalition of the third tarsometatarsal joint were found, thus indicating an involvement of approximately 2.97% of the examined feet. CONCLUSION: Our radiological findings are typical, and the prevalence found in this study was statistically significant, being similar to that described in the anthropological report (3.2%-6.8%).

Radiography, CT, and MRI of Hip and Lower Limb Disorders in Children and Adolescents.

Infants and children are vulnerable to congenital and developmental hip and lower extremity disorders. These disorders have diverse causes in pediatric patients, and owing to potential related complications that can lead to degenerative disease in adulthood, an accurate diagnosis is essential. A common disease is developmental dysplasia of the hip, which affects nearly 1% of newborns. This condition is best evaluated with US and conventional radiography. Slipped capital femoral epiphysis affects approximately 0.01% of young teenagers and is initially evaluated with radiography. Femoroacetabular impingement is a risk factor for early osteoarthritis and can be assessed with radiography, CT, or MRI. Limb length discrepancy is defined as a greater than 2-cm difference in length between paired bilateral lower extremities. There are several methods of measuring this difference, and the use of an accurate imaging modality is essential for treatment. Developmental bowing is a physiologic condition involving varus angulation of the knee and is best evaluated by using conventional radiography. Blount disease is a progressive pathologic genu varum centered at the tibia; the three subtypes are infantile, juvenile, and adolescent. In- and out-toeing disorders are caused by abnormal tibial and femoral torsion that usually self-corrects during lower limb growth. The ability to recognize these conditions is essential for differentiating those that will resolve spontaneously versus those that will require treatment. The imaging features of congenital and developmental hip and lower extremity disorders are reviewed, with emphasis on diagnosis, radiologic assessment, associated findings, and classification. ©RSNA, 2019.

The development of the anterior cruciate ligament in the paediatric population.

PURPOSE: The aim of this study was to retrospectively compile normative data on the anterior cruciate ligament (ACL) in the paediatric population with magnetic resonance imaging, emphasizing the differences between men and women. METHODS: In this retrospective study, musculoskeletal radiologists evaluated length, area, coronal and sagittal inclination of the ACL and inclination of the intercondylar notch. A total of 253 MR examinations (130 males and 123 females between 6 and 18 years of age) were included. The association between measurements, sex and age was considered. Linear and fractional polynomial regression models were used to evaluate the relationships between measurements. RESULTS: ACL length showed significant progressive growth (p < 0.001) with age in men and women, without characterization of growth peaks. ACL area in women showed more pronounced growth up to 11 years, stabilized from 11 to 14 years and then sustained a slight reduction. In men, ACL area showed more pronounced growth up to 12 years, stabilized from 12 to 15 years and then sustained slight reduction. Coronal and sagittal inclination of the ACL showed a significant progressive increase (p < 0.001) with age in both sexes, progressively verticalizing. The intercondylar roof inclination angle showed significant progressive reduction (p < 0.001) with age in both sexes. CONCLUSION: The area of the ACL does not accompany skeletal maturation, interrupting its growth around 11-12 years. Progressive verticalization of the ACL as well as of the intercondylar notch roof in the evaluated ages was also observed. The clinical relevance of this study is that the ACL presents different angular and morphologic changes during growth in the paediatric population. Since ACL repair is now being performed on younger children, recognition of the normal developmental changes of the ACL is of utmost importance for successful ACL graft placement. LEVEL OF EVIDENCE: III.

Different Patterns in Muscular Strength and Hypertrophy Adaptations in Untrained Individuals Undergoing Nonperiodized and Periodized Strength Regimens.

De Souza, EO, Tricoli, V, Rauch, J, Alvarez, MR, Laurentino, G, Aihara, AY, Cardoso, FN, Roschel, H, and Ugrinowitsch, C. Different patterns in muscular strength and hypertrophy adaptations in untrained individuals undergoing non-periodized and periodized strength regimens. J Strength Cond Res 32(5): 1238-1244, 2018-This study investigated the effects of nonperiodized (NP), traditional periodization (TP), and daily undulating periodization (UP) regimens on muscle strength and hypertrophy in untrained individuals. Thirty-three recreationally active males were randomly divided into 4 groups: NP: n = 8; TP: n = 9; UP: n = 8, and control group (C): n = 8. Experimental groups underwent a 12-week strength training program consisting of 2 sessions per week. Muscle strength and quadriceps cross-sectional area (QCSA) were assessed at baseline, 6 weeks (i.e., mid-point) and after 12 weeks. All training groups increased squat 1RM from pre to 6 weeks mid (NP: 17.02%, TP: 7.7%, and UP: 12.9%, p ≤ 0.002) and pre to post 12 weeks (NP: 19.5%, TP: 17.9%, and UP: 20.4%, p ≤ 0.0001). Traditional periodization was the only group that increased squat 1RM from 6 weeks mid to 12-week period (9.4%, p ≤ 0.008). All training groups increased QCSA from pre to 6 weeks mid (NP: 5.1%, TP: 4.6%, and UP: 5.3%, p ≤ 0.0006) and from pre to post 12 weeks (NP: 8.1%, TP: 11.3%, and UP: 8.7%, p ≤ 0.0001). From 6 weeks mid to 12-week period, TP and UP were the only groups that increased QCSA (6.4 and 3.7%, p ≤ 0.02). There were no significant changes for all dependent variables in C group across the time (p ≥ 0.05). In conclusion, our results demonstrated similar training-induced adaptations after 12 weeks of NP and periodized regimens. However, our findings suggest that in the latter half of the study (i.e., after the initial 6 weeks), the periodized regimens elicited greater rates of muscular adaptations compared with NP regimens. Strength coaches and practitioners should be aware that periodized regimens might be advantageous at latter stages of training even for untrained individuals.

Femoral Component Axial Rotation in the Gap-Balancing Approach to Total Knee Arthroplasty: Measurement by Computed Tomography.

BACKGROUND: Rotational malalignment of total knee arthroplasty (TKA) is a potential cause for revision surgery; therefore, it is important to have valid criteria for evaluation of normal component rotational alignment. Because computed tomography (CT) is considered the most accurate method to assess the rotational alignment of prosthetic components, the objectives in this study were define the femoral component (FC) rotation by measuring the posterior condylar angle (PCA) and the condylar twist angle (CTA) in a patient population that underwent gap-balancing TKA; determine the reliability of the FC rotation by using these measurements; evaluate the inter-relationship between the PCA and CTA; and finally evaluate the frequency and agreement in identification of the medial epicondyle sulcus (MES). METHODS AND RESULTS: In this retrospective study, 2 radiologists examined 50 CT scans. Mean PCA values of -2.26° and -2.56° (internal rotation) and CTA values of -5.54° and -6.28° (internal rotation) were attained by 2 observers with a higher interobserver concordance for the PCA. Both measurements were considered to be reliable. There was moderate interobserver agreement for MES identification, with the MES present in 64% and 78% of patients, as identified by 2 observers. CONCLUSION: Mean FC rotation values as evaluated by PCA were -2.26° and -2.56° and as evaluated by CTA were -5.54° and -6.28°. PCA and CTA measurement by CT is reliable; however, the use of PCA is preferable because of the higher observer concordance. PCA can be inferred by subtracting 3° or 4° from the CTA. MES was identified in 64% and 78% of patients, with only moderate interobserver agreement.

Effects of exercise intensity and occlusion pressure after 12 weeks of resistance training with blood-flow restriction.

PURPOSE: We compared the effects of different protocols of blood-flow restriction training (BFRT) with different occlusion pressures and/or exercise intensities on muscle mass and strength. We also compared BFRT protocols with conventional high-intensity resistance training (RT). METHODS: Twenty-six subjects had each leg allocated to two of five protocols. BFRT protocols were performed at either 20 or 40 % 1-RM with either 40 or 80 % occlusion pressure: BFRT20/40, BFRT20/80, BFRT40/40, and BFRT40/80. Conventional RT was performed at 80 % 1-RM (RT80) without blood-flow restriction. Maximum dynamic strength (1-RM) and quadriceps cross-sectional area (CSA) were assessed at baseline and after 12 weeks. RESULTS: Regarding muscle mass, increasing occlusion pressure was effective only at very low intensity (BFRT20/40 0.78 % vs. BFRT20/80 3.22 %). No additional increase was observed at higher intensities (BFRT40/40 4.45 % vs. BFRT40/80 5.30 %), with no difference between the latter protocols and RT80 (5.90 %). Exercise intensity played a role in CSA when comparing groups with similar occlusion pressure. Muscle strength was similarly increased among BFRT groups (~12.10 %) but to a lesser extent than RT80 (21.60 %). CONCLUSION: In conclusion, BFRT protocols benefit from higher occlusion pressure (80 %) when exercising at very low intensities. Conversely, occlusion pressure seems secondary to exercise intensity in more intense (40 % 1-RM) BFRT protocols. Finally, when considering muscle strength, BFRT protocols seem less effective than high-intensity RT.

Early adaptations to six weeks of non-periodized and periodized strength training regimens in recreational males.

UNLABELLED: This study compared quadriceps muscle cross-sectional area (CSA) and maximum strength (1RM) after three different short-term strength training (ST) regimens (i.e. non-periodized [NP], traditional-periodization [TP], and undulating-periodization [UP]) matched for volume load in previously untrained individuals. Thirty-one recreationally active males were randomly divided into four groups: NP: n = 9; TP: n = 9; UP: n = 8 and control group (C): n = 5. Experimental groups underwent a 6-week program consisting of two training sessions per week. Muscle strength was assessed at baseline and after the training period. Dominant leg quadriceps CSA was obtained through magnetic resonance imaging (MRI) at baseline and 48h after the last training session. RESULTS: The 1RM increased from pre to post only in the NP and UP groups (NP = 17.0 %, p = 0.002; UP = 12.9 %, p = 0.03), respectively. There were no significant differences in 1RM for LP and C groups after 6 weeks (TP = 7.7 %, p = 0.58, C = 1.2 %, p = 1.00). The CSA increased from pre to post in all of the experimental groups (NP = 5.1 %, p = 0.0001; TP = 4.6 %, p = 0.001; UP = 5.2 %, p = 0.0001), with no changes observed in the C group (p = 0.93). CONCLUSION: Our results suggest that different ST periodization regimens over a short-term (i.e. 6 weeks), volume load equated conditions seem to induce similar hypertrophic responses regardless of the loading scheme employed. In addition, for those recreational males who need to develop muscle strength in the short-term, the training regimen should be designed properly. Key pointsMuscle hypertrophy occurs within six weeks in recreationally active men regardless the ST training regimen employed.When the total volume is similar, training at greater intensities will demonstrate superior gains in the 1RM performance.Some caution should be exercised when interpreting our findings since long-term periodized regimens could produce different training-induced responses.

Changes in exercises are more effective than in loading schemes to improve muscle strength.

This study investigated the effects of varying strength exercises and loading scheme on muscle cross-sectional area (CSA) and maximum strength after 4 strength training loading schemes: constant intensity and constant exercise (CICE), constant intensity and varied exercise (CIVE), varied intensity and constant exercise (VICE), varied intensity and varied exercise (VIVE). Forty-nine individuals were allocated into 5 groups: CICE, CIVE, VICE, VIVE, and control group (C). Experimental groups underwent twice a week training for 12 weeks. Squat 1 repetition maximum was assessed at baseline and after the training period. Whole quadriceps muscle and its heads CSA were also obtained pretraining and posttraining. The whole quadriceps CSA increased significantly (p ≤ 0.05) in all of the experimental groups from pretest to posttest in both the right and left legs: CICE: 11.6 and 12.0%; CIVE: 11.6 and 12.2%; VICE: 9.5 e 9.3%; and VIVE: 9.9 and 11.6%, respectively. The CIVE and VIVE groups presented hypertrophy in all of the quadriceps muscle heads (p ≤ 0.05), whereas the CICE and VICE groups did not present hypertrophy in the vastus medialis and rectus femoris (RF), and in the RF muscles, respectively (p > 0.05). The CIVE group had greater strength increments than the other training groups (effect size confidence limit of the difference [ESCLdiff] CICE: 1.41-1.56; VICE: 2.13-2.28; VIVE: 0.59-0.75). Our findings suggest: (a) CIVE is more efficient to produce strength gains for physically active individuals; (b) as long as the training intensity reaches an alleged threshold, muscle hypertrophy is similar regardless of the training intensity and exercise variation.