Jae-Ho Moon

Respiratory muscle strength and cough capacity in patients with Duchenne muscular dystrophy.

The function of inspiratory muscles is crucial for effective cough as well as expiratory muscles in patients with Duchenne muscular dystrophy (DMD). However, there is no report on the correlation between cough and inspiratory muscle strength. To investigate the relationships of voluntary cough capacity, assisted cough techniques, and inspiratory muscle strength as well as expiratory muscle strength in patients with DMD (n = 32). The vital capacity (VC), maximum insufflation capacity (MIC), maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP) were measured. Unassisted peak cough flow (UPCF) and three different techniques of assisted PCF were evaluated. The mean value of MICs (1918 ± 586 mL) was higher than that of VCs (1474 ± 632 mL) (p < 0.001). All three assisted cough methods showed significantly higher value than unassisted method (212 ± 52 L/min) (F = 66.13, p < 0.001). Combined assisted cough technique (both manual and volume assisted PCF; 286 ± 41 L/min) significantly exceeded manual assisted PCF (MPCF; 246 ± 49 L/min) and volume assisted PCF (VPCF; 252 ± 45 L/min) (F = 66.13, p < 0.001). MIP (34 ± 13 cmH2O) correlated significantly with both UPCF and all three assisted PCFs as well as MEP (27 ± 10 cmH2O) (p < 0.001). Both MEP and MIP, which are the markers of respiratory muscle weakness, should be taken into account in the study of cough effectiveness.

Interlimb interaction and stabilization of contralateral leg in isokinetic knee evaluation

OBJECTIVE To determine if peak torque (PT) production during isokinetic knee testing is affected by the stabilization and movement patterns of the contralateral leg. DESIGN Repeated measure design. INTERVENTION AND MAIN OUTCOME MEASURE Thirty subjects participated in comparing the force outputs in relation to the movement pattern of both legs. Another group of 45 subjects volunteered to perform five maximal isokinetic extension-flexion contractions in each of three different knee testing conditions: (1) without stabilization of the contralateral leg; (2) with a bar in front of the ankle joint of the contralateral leg; (3) with the contralateral leg strapped just above the level of the malleoli and the muscles of that leg induced reciprocally to perform isometric contractions with respect to the testing leg. PT was used to compare the strength of three different conditions. RESULTS Significantly greater PT was measured when the contralateral leg of the subject was fixed and induced to contract reciprocally. CONCLUSION More rigorous standardization of isokinetic strength testing procedures is needed due to differences in PT production of knee muscles according to the stabilization and movement pattern of the contralateral leg.