Background: Immersive 360° video provides consistent demonstrations of clinical procedures. We compared an immersive-video program with conventional simulation, each followed by a common hands-on seminar. Methods: Thirty-two teaching subgroups were randomized 1:1. Of 443 consenting second-year nursing students, 442 were analyzed (222 virtual reality [VR]; 220 control). The four-hour first session addressed urinary, nasogastric and rectal catheterization through faculty demonstrations in 360°, questions, feedback and Plus/Delta debriefing without physical practice in VR, or live demonstration and practice on part-task trainers in control. One week later, both arms attended the same four-hour seminar with theory, practice, a three-station objective structured clinical examination (OSCE) scored independently by two blinded assessors, and a 30-item knowledge test. Knowledge was reassessed four weeks after Session 1. Within the VR arm, an exploratory paired analysis compared satisfaction with previous VR experiences and with the study seminar. Linear models accounted for clustering by teaching subgroup; item-level analyses were exploratory. Results: Mean composite OSCE scores were 87.33 ± 5.05 in the VR arm and 70.70 ± 8.51 in the control arm, on a 0–100 scale. The age- and sex-adjusted difference was 16.65 points (95% CI 14.37–18.94; wild cluster bootstrap, p < 0.001). Performance scores favored VR across all three procedures. Knowledge scores, on a 0–30 scale, were 19.02 ± 2.84 versus 14.12 ± 3.78 immediately after the common seminar and 19.45 ± 2.75 versus 15.21 ± 3.83 four weeks after Session 1. The unadjusted between-arm difference at four weeks was 4.24 points (cluster-robust 95% CI 3.24–5.24). Exploratory item-level analyses favored VR on ten checklist items, whereas material preparation favored control. Within the VR arm, satisfaction with the study seminar was higher than with previous VR experiences. Conclusions: Immersive 360° video with questions and debriefing, followed by hands-on practice, improved simulated procedural performance compared with conventional training. The findings support this blended sequence, not replacement of physical practice or an isolated effect of immersion. Knowledge outcomes require caution because of measurement limitations. Trial Registration: Retrospectively registered on the Open Science Framework on 6 July 2026: 10.17605/OSF.IO/T5JSW.

Background: Diaphragm thickness may affect both inspiratory and expiratory function. The ultrasound assessment of diaphragm thickness could be a valuable tool for respiratory muscle evaluation in older adults, although additional research is needed to clarify its association with respiratory functional parameters. Objectives: The primary objective was to explore the relationship between diaphragm thickness (DT), maximal inspiratory pressure (MIP), and peak expiratory flow (PEF) in institutionalized older adults. A secondary objective was to compare MIP and PEF values between participants with normal and thin diaphragm thickness. Methods: A cross-sectional exploratory study was conducted among older adults (n = 36) residing in long-term care facilities (LTCFs) in Spain. DT was measured at the end of maximum inspiration (DTi) and at the end of expiration at rest (DTe) in the supine position. The diaphragm thickening difference (DTD) and diaphragm fraction (DTF) were calculated. A thin diaphragm was defined as a diaphragm thickness (DTe) <1.6 mm in men and <1.4 mm in women. The maximum inspiratory pressure (MIP) was measured using a Powerbreath KH1 device, and the peak expiratory flow (PEF) was measured using Datospir Peak-10. Spearman’s rank correlation coefficient and linear regression models were used to explore the association between diaphragm thickness and respiratory muscle function. Statistical analysis was performed using IBM SPSS Statistics 22.0. Results: The mean age of the participants was 82.4 ± 7.9 years (24 females–12 males). Significant correlations were observed among most ultrasound-derived measures. DTi was positively associated with MIP (ρ = 0.403, 95% CI 0.065–0.658; q = 0.033) and PEF (ρ = 0.534, 95% CI 0.235–0.741; q = 0.003), DTe with MIP (ρ = 0.445, 95% CI 0.116–0.686; q = 0.020), and DTD with PEF (ρ = 0.475, 95% CI 0.158–0.703; q = 0.012). Compared with participants with normal diaphragm thickness, those with a thin diaphragm exhibited lower MIP (β = −18.43, 95% CI: −32.76 to −4.18; p = 0.013). Conclusions: Diaphragm thickness was positively associated with inspiratory muscle strength and peak expiratory flow. Participants with a thin diaphragm demonstrated lower respiratory muscle performance than those with normal diaphragm thickness. However, these findings should be interpreted with caution, and additional studies are needed to confirm these associations.