posted on 2025-05-10, 15:23authored byBrooke K. Coombes, Brandon Ziegenfuss, Michael David, Rohitha Badya, Wolbert van den Hoorn, Françiois Hug, Kylie Tucker
Purpose: The purpose of this study was to compare regional elastic properties between anterior and posterior regions of the patellar tendon, and individual quadriceps muscles, over a range of knee flexion angles. Methods: An isokinetic dynamometer passively positioned the non-dominant knee of 19 young, healthy participants, at 25°, 40°, 55°, 70° and 85° flexion. Shear wave velocity (SWV, an index of tissue elasticity) was measured using ultrasound shear wave elastography in a relaxed (passive) state, confirmed by electromyography. Results: SWV of the patellar tendon and quadriceps muscles increased with knee flexion (longer muscle-tendon unit; P < 0.001). Within the proximal third of the patellar tendon, SWV was lower in the posterior than anterior region at 70° (P = 0.002) and 85° (P < 0.001), but not at 25°, 40° or 55° (region-by-angle interaction, P = 0.007). No differences were found between anterior and posterior regions within the middle third of the patellar tendon (P = 0.332). For the quadriceps muscles, a significant muscle-by-angle (P < 0.001) interaction was also observed. SWV of VL was greater than VM at 55° (P = 0.005), 70° (P = 0.001) and 85° (P < 0.001), but not at 25° or 40°. SWV of RF was lower than VL at all angles (all P < 0.002) and lower than VM at 55°, 70° and 85° (all P < 0.002). Conclusions: Passive knee flexion at and beyond 70° was associated with non-uniform elastic properties within the proximal patellar tendon and between individual quadriceps muscles. To what extent this heterogeneity of passive elastic properties contributes to injury remains unknown.
History
Journal title
European Journal of Applied Physiology
Volume
118
Issue
1
Pagination
213-221
Publisher
Springer
Language
en, English
College/Research Centre
Faculty of Health and Medicine
School
School of Medicine and Public Health
Rights statement
This is a post-peer-review, pre-copyedit version of an article published in the European Journal of Applied Physiology. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00421-017-3763-1.