Search

The aim of this study was to assess the agreement of three different automated methods of identifying force-onset (40 N, 5 SDs, and 3 SDs) with manual identification, during the isometric mid-thigh pull (IMTP). Fourteen resistance-trained participants with >6 months experience training with the power clean volunteered to take part. After three familiarisation sessions, the participants performed five maximal IMTPs separated by 1 min of rest. Fixed bias was found between 40 N and manual identification for time at force-onset. No proportional bias was present between manual identification and any automated threshold. Fixed bias between manual identification and automated was present for force at onset and F150. Proportional but not fixed bias was found for F50 between manual identification and all automated thresholds. Small to moderate differences (Hedges g = −0.487- −0.692) were found for F90 between all automated thresholds and manual identification, while trivial to small differences (Hedges g = −0.122—−0.279) were found between methods for F200 and F250. Based on these results, strength and conditioning practitioners should not use a 40 N, 5 SDs, or 3 SDs threshold interchangeably with manual identification of force-onset when analysing IMTP force–time curve data. [ABSTRACT FROM AUTHOR]

Kotani, Y, Lake, J, Guppy, SN, Poon, W, Nosaka, K, Hori, N, and Haff, GG. The reliability of the squat jump force-velocity and load-velocity profiles. J Strength Cond Res 36(11): 3000–3007, 2022—The purpose of this study was to investigate the between-session reliability of the squat jump force-velocity (FV) and load-velocity (LV) profiles. Eighteen subjects (age = 28.1 ± 4.8 years; height = 1.7 ± 9.7; body mass = 74.7 ± 12.8) who could back squat >1.5 times body mass participated in this study. Each subject completed a familiarization session, followed by 2 experimental sessions each separated by 72 hours. Subjects performed a series of squat jumps on a force plate against external loads between 0 and 100% of their body mass in a quasi-randomized block order. Intraclass correlation coefficient (ICC) and coefficient of variation (CV) were used to examine the between-session reliability. Peak velocity (PV) and mean velocity (MV) at each load were highly reliable (ICC >0.80, CV% <7.41, SEM <0.13 m·s−1, smallest detectable difference [SDD] <0.31 m·s−1, ES <0.21). Force-velocity profiles created with peak force and relative peak force resulted in poor to excellent reliability (ICC = 0.34–0.92, CV% = 11.9–26.3). When mean and relative mean forces were used to create FV profiles, there was poor to good reliability (ICC = 0.03–0.85, CV% = 18.1–39.4). When the LV profile was calculated with PV (ICC = 0.60–0.90, CV% = 7.9–16.9) or MV (ICC = 0.49–0.91, CV% = 11.1–23.4), there was poor to excellent reliability. There was no time effect found between sessions for both FV and LV profiles. The squat jump FV and LV profiles established with a force plate are not reliable. Therefore, these profiles are not recommended to be used to inform programming decisions. [ABSTRACT FROM AUTHOR]

Supplemental Digital Content is Available in the Text. Guppy, SN, Kotani, Y, Brady, CJ, Connolly, S, Comfort, P, and Haff, GG. Title: The reliability and magnitude of time-dependent force-time characteristics during the isometric mid-thigh pull are impacted by both testing protocol and analysis choices. J Strength Cond Res 36(5): 1191–1199, 2022—This study aimed to investigate whether the use of short-duration (SHORT) isometric midthigh pull (IMTP) trials resulted in greater reliability and magnitude of time-dependent force-time characteristics than traditionally performed IMTP trials (TRAD). Fourteen subjects with >6 months' training experience with the power clean volunteered to take part in the study. Subjects performed five ∼1-second IMTP trials (SHORT) and five 5-second IMTP trials (TRAD). SHORT resulted in substantially more reliable rate of force development (RFD) measures (intraclass correlation coefficient [ICC] = 0.97–0.99; coefficient of variation [CV] = 2.6–7.0%), particularly during time bands from force-onset to 150 ms, compared with TRAD when trials were selected for analysis based on peak force (ICC = 0.66–0.83; CV = 14.1–38.5%). Selecting TRAD trials based on RFD0-200 resulted in similar reliability compared with SHORT of those same epochs (ICC = 0.97–0.99; CV = 2.5–7.8%). Furthermore, SHORT resulted in significantly greater force at specific time points, RFD, and impulse compared with TRAD trials (p = 0.001–0.033; g = −0.16 to −0.66). Based on these results, strength and conditioning professionals should use specific testing protocols (i.e., TRAD and SHORT) depending on the component of an athlete's force-generating capacity that they wish to assess and remain aware of the effect analysis choices they have on the reliability of IMTP force-time characteristics. [ABSTRACT FROM AUTHOR]

Seventeen strength and power athletes (n = 11 males, 6 females; height: 177.5 ± 7.0 cm, 165.8 ± 11.4 cm; body mass: 90.0 ± 14.1 kg, 66.4 ± 13.9 kg; age: 30.6 ± 10.4 years, 30.8 ± 8.7 years), who regularly performed weightlifting movements during their resistance training programs, were recruited to examine the effect of altering body posture and barbell position on the between-session reliability of force-time characteristics generated in the isometric mid-thigh pull (IMTP). After participants were familiarised with the testing protocol, they undertook two testing sessions which were separated by seven days. In each session, the participants performed three maximal IMTP trials in each of the four testing positions examined, with the order of testing randomized. In each position, no significant differences were found between sessions for all force-time characteristics (p = >0.05). Peak force (PF), time-specific force (F50, F90, F150, F200, F250) and IMP time-bands (0–50, 0–90, 0–150, 0–200, 0–250 ms) were reliable across each of the four testing positions (ICC ≥ 0.7, CV ≤ 15%). Time to peak force, peak RFD, RFD time-bands (0–50, 0–90, 0–150, 0–200, 0–250 ms) and peak IMP were unreliable regardless of the testing position used (ICC = <0.7, CV = >15%). Overall, the use of body postures and barbell positions during the IMTP that do not correspond to the second pull of the clean have no adverse effect on the reliability of the force-time characteristics generated. [ABSTRACT FROM AUTHOR]

Department of Cardiovascular Surgery, Okayama University Hospital, 2-5-1 Shikatacho, Kitaku, Okayama 700-8558, Japan. Corrigendumto'Norwoodprocedurewithrightventricleto pulmonaryarteryconduit:asingle-centre20-yearexperience' [EurJCardiothoracSurg2020;58:230-236] YasuyukiKobayashi a, †,YasuhiroKotani a, *, †,YosukeKuroko a,TakuyaKawabata a,ShunjiSano b and ShingoKasahara a a Department of Cardiovascular Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hospital, Okayama, Japan b Department of Pediatric Cardiothoracic Surgery, University of California, San Francisco, CA, USA * Corresponding author. Cite this article as: Kobayashi Y, Kotani Y, Kuroko Y, Kawabata T, Sano S, Kasahara S. Corrigendum to 'Norwood procedure with right ventricle to pulmonary artery conduit: a single-centre 20-year experience' Eur J Cardiothorac Surg 2021;59:931. [Extracted from the article]

We consider periodic Hamiltonians on a three-dimensional (3-D) lattice with a spectral gap not only on the bulk but also on two edges at the common Fermi level. By using K-theory applied for the quarter-plane Toeplitz extension, two topological invariants are defined. One is defined for the gapped bulk and edge Hamiltonians, and the non-triviality of the other means that the corner Hamiltonian is gapless. We prove a correspondence between these two invariants. Such gapped Hamiltonians can be constructed from Hamiltonians of 2-D type A and 1-D type AIII topological insulators, and its corner topological invariant is the product of topological invariants of these two phases. [ABSTRACT FROM AUTHOR]

We show that the bulk-edge correspondence for two-dimensional type A and type topological insulators follows directly from the cobordism invariance of the index. [ABSTRACT FROM AUTHOR]

An 8-year-old girl with no history of chest pain or exertional dyspnea was admitted for atrial septal defect closure. Transthoracic echocardiography showed a sac in the right atrium, protruding from the left ventricle. A left ventricular aneurysm was confirmed by cardiac catheterization. At surgery, the protruding saccular aneurysm arising from the left ventricle was located between the atrial septal defect and the tricuspid valve. We closed the orifice with interrupted sutures from the right atrium. The atrial septal defect was closed with an autologous pericardial patch. Histology showed the aneurysmal wall had no myocardial layer, being replaced by fibrous tissue. [ABSTRACT FROM AUTHOR]

Background The surgical outcomes of hypoplastic left heart syndrome with intact atrial septum remains very poor in spite of the introduction of prenatal diagnosis before the Norwood operation. The hybrid operation consisting of bilateral pulmonary artery banding and balloon atrioseptectomy is one of the treatment strategies to potentially improve this patient population, however, the long-term outcomes are unknown. Methods Six consecutive patients with hypoplastic left heart syndrome with intact atrial septum, who underwent the hybrid operation between October 2006 and July 2014, were retrospectively reviewed. Hypoplastic left heart syndrome with highly restrictive atrial communication was excluded. Results Three patients died after the hybrid operation, due to sepsis, cerebral bleeding, and heart failure. Three patients underwent the modified Norwood operation. One of these died due to severe hypoxia while awaiting the bidirectional Glenn operation. The others underwent a bidirectional Glenn operation and subsequent Fontan completion but died due to lung dysfunction and sudden hemoptysis. Conclusions The hybrid operation for hypoplastic left heart syndrome with intact atrial septum may have improved the neonatal outcome and Fontan completion rate in this extremely high-risk group of patients, but the long-term outcome remains dismal. Considering the late mortality related to pulmonary complications, aggressive fetal intervention to create a nonrestrictive atrial septal communication to promote normal development of the pulmonary vessels may be the last resort to improve the long-term outcome. [ABSTRACT FROM AUTHOR]