Abstract
Purpose: The aim of this study was to examine the change and relationship among quadriceps torque (QT) and physical function in adult lung transplant (LTx) patients undergoing rehabilitation.
Methods: A prospective study assessed 6-min walk test (6MWT) distance, QT, and Short Physical Performance Battery (SPPB) at the start of pre-habilitation and 10-12 wk post-LTx. Functional outcomes were examined for within-group differences for participants who completed center-based rehabilitation between September 2019 and March 2020 and participants who completed telerehabilitation ("telerehab") between March 2020 and June 2021 during COVID-19. Relationships between QT, SPPB, and 6MWT were examined pre- and post-LTx.
Results: A total of 49 LTx recipients were included (30 men, 61 [56-67] yr, 26 center-based rehab, and 23 telerehab). The 6MWT increased (median 75 m: 95% CI, 35 - 117, P < .0001), and the telerehab group showed an LTx decrease in QT (-9.6 Nm: 95% CI, -29 to -2.3, P = .02) and an increased gait speed (0.21 m/sec: 95% CI, 0.11 - 0.47, P < .0001). Pre-LTx QT showed a moderate correlation to pre-LTx SPPB (r = 0.41, P = .004) and weak correlations to gait speed and 6MWT (r ranging from 0.21 to 0.35, P < .05). Post-LTx QT showed moderate correlations to post-LTx SPPB (r = 0.43, P = .002), gait speed (r = 0.54, P < .001), five-time sit-to-stand (r =-0.57, P < .0001), and 6MWT (r = 0.62, P < .0001).
Conclusions: Early post-LTx 6MWT and gait speed increased with no improvement in QT or other SPPB components. Correlations between QT and measures of exercise capacity and lower limb function were stronger post-LTx. Serial measurements may further inform functional trajectories and rehabilitation models.