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INTRODUCTION/AIM: The most common limb girdle muscular dystrophy (LGMD) worldwide is LGMD type R1 (LGMDR1). The aim of this study was to correlate the MRI findings with functional scores and to describe the whole-body MRI (WBMRI) pattern in a LGMDR1 Brazilian cohort. METHODS: LGMDR1 patients under follow-up in three centers were referred for the study. Clinical data were collected and a functional evaluation was performed, consisting of Gardner-Medwin and Walton (GMW) and Brooke scales. All patients underwent a WBMRI study (1.5T) with axial T1 and STIR images. Fifty-one muscles were semiquantitatively assessed regarding fatty infiltration and muscle edema. RESULTS: The study group consisted of 18 patients. The highest fatty infiltration scores involved the serratus anterior, biceps femoris long head, adductor magnus, and lumbar erector spinae. There was a latero-medial and caudo-cranial descending gradient of involvement of the paravertebral muscles, with erector spinae being significantly more affected than the transversospinalis muscles (p < 0.05). A striped appearance that has been dubbed the "pseudocollagen sign" was present in 72% of the patients. There was a positive correlation between the MRI score and GMW (Rho:0.83) and Brooke (Rho:0.53) scores. DISCUSSION: WBMRI in LGMDR1 allows a global patient evaluation including involvement of the paraspinal muscles, usually an underestimated feature in the clinical and imaging study of myopathies. Knowledge of the WBMRI pattern of LGMDR1 involvement can be useful in the diagnostic approach and in future studies to identify the best target muscles to serve as outcome measures in clinical trials.

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ABSTRACT: Longo, AR, Silva-Batista, C, Pedroso, K, de Salles Painelli, V, Lasevicius, T, Schoenfeld, BJ, Aihara, AY, de Almeida Peres, B, Tricoli, V, and Teixeira, EL. Volume load rather than resting interval influences muscle hypertrophy during high-intensity resistance training. J Strength Cond Res 36(6): 1554-1559, 2022-Interset rest interval has been proposed as an important variable for inducing muscle mass and strength increases during resistance training. However, its influence remains unclear, especially when protocols with differing intervals have equalized volume. We aimed to compare the effects of long (LI) vs. short rest interval (SI) on muscle strength (one repetition maximum [1RM]) and quadriceps cross-sectional area (QCSA), with or without equalized volume load (VL). Twenty-eight subjects trained twice a week for 10 weeks. Each subject's leg was allocated to 1 of 4 unilateral knee extension protocols: LI, SI, SI with VL -matched by LI (VLI-SI), and LI with VL-matched by SI (VSI-LI). A 3-minute rest interval was afforded in LI and VSI-LI protocols, while SI and VLI-SI employed a 1-minute interval. All subjects trained with a load corresponding to 80% 1RM. One repetition maximum and QCSA were measured before and after training. All protocols significantly increased 1RM values in post-training (p < 0.0001; LI: 27.6%, effect size [ES] = 0.90; VLI-SI: 31.1%, ES = 1.00; SI: 26.5%, ES = 1.11; and VSI-LI: 31.2%, ES = 1.28), with no significant differences between protocols. Quadriceps cross-sectional area increased significantly for all protocols in post-training (p < 0.0001). However, absolute changes in QCSA were significantly greater in LI and VLI-SI (13.1%, ES: 0.66 and 12.9%, ES: 0.63) than SI and VSI-LI (6.8%, ES: 0.38 and 6.6%, ES: 0.37) (both comparisons, p < 0.05). These data suggest that maintenance of high loads is more important for strength increases, while a greater VL plays a primary role for hypertrophy, regardless of interset rest interval.

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BACKGROUND: Proximal humerus fractures (PHF) are frequent, however, several studies show low inter-rater agreement in the diagnosis and treatment of these injuries. Differences are usually related to the experience of the evaluators and/or the diagnostic methods used. This study was designed to investigate the hypothesis that shoulder surgeons and diagnostic imaging specialists using 3D printing models and shoulder CT scans in assessing proximal humerus fractures. METHODS: We obtained 75 tomographic exams of PHF to print three-dimensional models. After, two shoulder surgeons and two specialists in musculoskeletal imaging diagnostics analyzed CT scans and 3D models according to the Neer and AO/OTA group classification and suggested a treatment recommendation for each fracture based on the two diagnostic methods. RESULTS: The classification agreement for PHF using 3D printing models among the 4 specialists was moderate (global k = 0.470 and 0.544, respectively for AO/OTA and Neer classification) and higher than the CT classification agreement (global k = 0.436 and 0.464, respectively for AO/OTA and Neer). The inter-rater agreement between the two shoulder surgeons were substantial. For the AO/OTA classification, the inter-rater agreement using 3D printing models was higher (k = 0.700) than observed for CT (k = 0.631). For Neer classification,  inter-rater agreement with 3D models was similarly higher (k = 0.784) than CT images (k = 0.620). On the other hand, the inter-rater agreement between the two specialists in diagnostic imaging was moderate. In the AO/OTA classification, the agreement using CT was higher (k = 0.532) than using 3D printing models (k = 0.443), while for Neer classification, the agreement was similar for both 3D models (k = 0.478) and CT images (k = 0.421). Finally, the inter-rater agreement in the treatment of PHF by the 2 surgeons was higher for both classifications using 3D printing models (AO/OTA-k = 0.818 for 3D models and k = 0.537 for CT images). For Neer classification, we saw k = 0.727 for 3D printing models and k = 0.651 for CT images. CONCLUSION: The insights from this diagnostic pilot study imply that for shoulder surgeons, 3D printing models improved the diagnostic agreement, especially the treatment indication for PHF compared to CT for both AO/OTA and Neer classifications On the other hand, for specialists in diagnostic imaging, the use of 3D printing models was similar to CT scans for diagnostic agreement using both classifications. TRIAL REGISTRATION: Brazil Platform under no. CAAE 12273519.7.0000.5505.

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ABSTRACT: Teixeira, EL, Painelli, VdS, Schoenfeld, BJ, Silva-Batista, C, Longo, AR, Aihara, AY, Cardoso, FN, Peres, BdA, and Tricoli, V. Perceptual and neuromuscular responses adapt similarly between high-load resistance training and low-load resistance training with blood flow restriction. J Strength Cond Res 36(9): 2410-2416, 2022-This study compared the effects of 8 weeks of low-load resistance training with blood flow restriction (LL-BFR) and high-load resistance training (HL-RT) on perceptual responses (rating of perceived exertion [RPE] and pain), quadriceps cross-sectional area (QCSA), and muscle strength (1 repetition maximum [RM]). Sixteen physically active men trained twice per week, for 8 weeks. One leg performed LL-BFR (3 sets of 15 repetitions, 20% 1RM), whereas the contralateral leg performed HL-RT (3 sets of 8 repetitions, 70% 1RM). Rating of perceived exertion and pain were evaluated immediately after the first and last training sessions, whereas QCSA and 1RM were assessed at baseline and after training. Rating of perceived exertion was significantly lower (6.8 ± 1.1 vs. 8.1 ± 0.8, p = 0.001) and pain significantly higher (7.1 ± 1.2 vs. 5.8 ± 1.8, p = 0.02) for LL-BFR than that for HL-RT before training. Significant reductions in RPE and pain were shown for both protocols after training (both p < 0.0001), although no between-protocol differences were shown in absolute changes ( p = 0.10 and p = 0.48, respectively). Both LL-BFR and HL-RT were similarly effective in increasing QCSA (7.0 ± 3.8% and 6.3 ± 4.1%, respectively; both p < 0.0001) and 1RM (6.9 ± 4.1% and 13.7 ± 5.9%, respectively; both P < 0.0001), although absolute changes for 1RM in HL-RT were greater than LL-BFR ( p = 0.001). In conclusion, LL-BFR produces lower RPE values and a higher pain perception than HL-RT. However, consistent application of these approaches result in chronic adaptations so that there are no differences in perceptual responses over the course of time. In addition, muscle strength is optimized with HL-RT despite similar increases in muscle hypertrophy between conditions.

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ABSTRACT: Lasevicius, T, Schoenfeld, BJ, Silva-Batista, C, Barros, TdS, Aihara, AY, Brendon, H, Longo, AR, Tricoli, V, Peres, BdA, and Teixeira, EL. Muscle failure promotes greater muscle hypertrophy in low-load but not in high-load resistance training. J Strength Cond Res 36(2): 346-351, 2022-The purpose of this study was to investigate the effects of an 8-week resistance training program at low and high loads performed with and without achieving muscle failure on muscle strength and hypertrophy. Twenty-five untrained men participated in the 8-week study. Each lower limb was allocated to 1 of 4 unilateral knee extension protocols: repetitions to failure with low load (LL-RF; ∼34.4 repetitions); repetitions to failure with high load (HL-RF; ∼12.4 repetitions); repetitions not to failure with low load (LL-RNF; ∼19.6 repetitions); and repetitions not to failure with high load (HL-RNF; ∼6.7 repetitions). All conditions performed 3 sets with total training volume equated between conditions. The HL-RF and HL-RNF protocols used a load corresponding to 80% 1 repetition maximum (RM), while LL-RF and LL-RNF trained at 30% 1RM. Muscle strength (1RM) and quadriceps cross-sectional area (CSA) were assessed before and after intervention. Results showed that 1RM changes were significantly higher for HL-RF (33.8%, effect size [ES]: 1.24) and HL-RNF (33.4%, ES: 1.25) in the post-test when compared with the LL-RF and LL-RNF protocols (17.7%, ES: 0.82 and 15.8%, ES: 0.89, respectively). Quadriceps CSA increased significantly for HL-RF (8.1%, ES: 0.57), HL-RNF (7.7%, ES: 0.60), and LL-RF (7.8%, ES: 0.45), whereas no significant changes were observed in the LL-RNF (2.8%, ES: 0.15). We conclude that when training with low loads, training with a high level of effort seems to have greater importance than total training volume in the accretion of muscle mass, whereas for high load training, muscle failure does not promote any additional benefits. Consistent with previous research, muscle strength gains are superior when using heavier loads.

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