Article Title



Lauren E. Pacinelliƚ1, William C. Hawkinsǂ2, Ryan M. Thieleǂ1, John P. Vardimanǂ1 1 Kansas State University, Manhattan, KS 2University of Southern Indiana, Evansville, IN

PURPOSE: Determine the reliability of ultrasonography (US) measurements of pennation angle (PA) of the biceps femoris (BF) at different knee joint positions. Joint positions included 90°, mid- (MidROM), and end-range of motion (ROM) (EndROM). METHODS: Seventeen healthy, college aged females (mean±SD: age=21.12±0.78; mass=61.34kg±18.55kg; height=165.41cm±7.66cm) volunteered for this investigation on 2 non-consecutive days at the same time of day (±2h). During each visit, participants were placed in a supine position, with the right hip and knee joints at 90° of flexion against a horizontal support, with restraining straps across the left limb. Full ROM was assessed with manual goniometry, starting from the initial 90° hip/knee joint angles and passively extending the lower limb to the point of patient self-reported EndROM. US measurements were recorded at 90°, MidROM, and the EndROM joint positions. US images of the right BF were obtained utilizing a portable ultrasonography device with a linear-array probe. US settings were enhanced to improve image quality, including the gain (50dB), depth (8cm), and frequency (12MHz). All US images were scanned in a longitudinal position at 50% of the distance between the greater trochanter and the lateral joint line of the knee. PAs were measured from the muscle fascicles to the deep fascia of the muscle using a third party image analysis software. Reliability for PA calculations were determined using intraclass correlation coefficient (ICC, model 2,1) and standard error of measurement (SEM) also reported as a percentage (SEM%). Systematic variability was examined using separate one-way repeated measures analyses of variance (ANOVAs). RESULTS: The ANOVAs indicated no systematic variability in any of the dependent variables (P>0.05). The ICCs and SEM values expressed as a percentage of the mean ranged from 0.311-0.735 and 11.75-26.41% for PA measurements of the BF. CONCLUSION: These findings demonstrate that longitudinal ultrasonography may be consistent and a moderately reliable assessment technique for measuring PA in practical joint positions (90°) but not as the muscle fascicles become lengthened (MidROM and EndROM).

This document is currently not available here.