Influence of horizontal resistance loads on spatiotemporal and ground reaction force variables during maximal sprint acceleration

by Norihide Sugisaki, Kai Kobayashi, Takaya Yoshimoto, Naotoshi Mitsukawa, Hiroyasu Tsuchie, Yohei Takai, Hiroaki Kanehisa

This study aimed to elucidate the influence of horizontal resistance loads on the spatiotemporal and ground reaction force (GRF) variables during maximal sprint acceleration. Nine male sprinters (20.2 ± 1.2 years; 175.3 ± 4.5 cm, 69.7 ± 6.1 kg) performed sprint-running with six loading conditions of one unresisted and five resisted loads of 4, 6, 8, 10, and 12 kg using a resistance training device with intelligent drag technology. During the trials, the GRFs for all steps were determined using a 50-m force plate system. The spatiotemporal and GRF variables at running velocity of every 0.5 m/s were obtained and compared across the loading conditions. The maximal running velocity under 0, 4, 6, 8, 10, and 12 kg loading conditions were 9.84 ± 0.41, 8.55 ± 0.41, 8.09 ± 0.33, 7.62 ± 0.34, 7.11 ± 0.31, and 6.71 ± 0.29 m/s, respectively. ANOVA revealed significant main effects of load on the measured variables (η² = 0.236–0.715, p

The association between cardiopulmonary exercise testing and postoperative outcomes in patients with lung cancer undergoing lung resection surgery: A systematic review and meta-analysis

by Nabeela Arbee-Kalidas, Hlamatsi Jacob Moutlana, Yoshan Moodley, Moses Mogakolodi Kebalepile, Palesa Motshabi Chakane

Background

Exercise capacity should be determined in all patients undergoing lung resection for lung cancer surgery and cardiopulmonary exercise testing (CPET) remains the gold standard. The purpose of this study was to investigate associations between preoperative CPET and postoperative outcomes in patients undergoing lung resection surgery for lung cancer through a review of the existing literature.

Methods

A search was conducted on PubMed, Scopus, Cochrane Library and CINAHL from inception until December 2022. Studies investigating associations between preoperative CPET and postoperative outcomes were included. Risk of bias was assessed using the QUIPS tool. A random effect model meta-analysis was performed. I² > 40% indicated a high level of heterogeneity.

Results

Thirty-seven studies were included with 6450 patients. Twenty-eight studies had low risk of bias. V˙O2 peak is the oxygen consumption at peak exercise and serves as a marker of cardiopulmonary fitness. Higher estimates of V˙O2 peak, measured and as a percentagege of predicted, showed significant associations with a lower risk of mortality [MD: 3.66, 95% CI: 0.88; 6.43 and MD: 16.49, 95% CI: 6.92; 26.07] and fewer complications [MD: 2.06, 95% CI: 1.12; 3.00 and MD: 9.82, 95% CI: 5.88; 13.76]. Using a previously defined cutoff value of > 15mL/kg/min for V˙O2 peak, showed evidence of decreased odds of mortality [OR: 0.55, 95% CI: 0.28–0.81] and but not decreased odds of postoperative morbidity [OR: 0.82, 95% CI: 0.64–1.00]. There was no relationship between V˙E/V˙CO2 slope, which depicts ventilatory efficiency, with mortality [MD: -9.60, 95% CI: -27.74; 8.54] however, patients without postoperative complications had a lower preoperative V˙E/V˙CO2 [MD: -2.36, 95% CI: -3.01; -1.71]. Exercise load and anaerobic threshold did not correlate with morbidity or mortality. There was significant heterogeneity between studies.

Conclusions

Estimates of cardiopulmonary fitness as evidenced by higher V˙O2 peak, measured and as a percentage of predicted, were associated with decreased morbidity and mortality. A cutoff value of V˙O2 peak > 15mL/kg/min was consistent with improved survival but not with fewer complications. Ventilatory efficiency was associated with decreased postoperative morbidity but not with improved survival. The heterogeneity in literature could be remedied with large scale, prospective, blinded, standardised research to improve preoperative risk stratification in patients with lung cancer scheduled for lung resection surgery.

The effect of a brinzolamide/brimonidine fixed combination on optic nerve head blood flow in rabbits

by Nana Takahashi, Kota Sato, Naoki Kiyota, Mai Yamazaki, Eriko Kunikane, Toru Nakazawa

Purpose

The purpose of this study was to investigate the effect of a 1% brinzolamide and 0.1% brimonidine fixed combination (BBFC) on ONH blood flow (BF) in rabbits.

Methods

A crossover study was conducted on pigmented rabbits; a physiological saline solution, brinzolamide, or BBFC was administered for eight days. ONH BF, intraocular pressure (IOP) and systemic parameters were measured before the eighth day’s first dose and at 6, 9, 12, and 14 hours after the dose. ONH BF was assessed using laser speckle flowgraphy, and mean blur rate (MBR) values were calculated. The percentage against baseline of each parameter was calculated, and intergroup comparisons were performed at each time point.

Results

There were no significant differences in the percentage change in systemic parameters. At 6 hours after administration, the BBFC group showed a significantly higher percentage change in large vessel area-MBR (%MV) compared to the control group (98.6±16.8%MV vs. 81.3±7.9%MV, P = 0.03). On the other hand, the brinzolamide group did not show a significant difference. Both the brinzolamide and BBFC groups had significantly lower percentage change in IOP (%IOP) compared to the control group (90.6±5.0%IOP, 93.3±2.9%IOP, and 99.2±1.7%IOP, respectively, P Conclusion

BBFC effectively reduces IOP and mitigates diurnal fluctuation-induced decreases in ONH BF.