Changes of the Patellar Tendon Moment Arm Length in Different Knee Angles: A Biomechanical in Vivo Study

Document Type : TECHNICAL NOTE

Authors

1 1 Faculty of Sports sciences, University of Mazandaran, Babolsar, Iran- 3 Mobility Impairment Research Center, Babol University of Medical Sciences, Iran

2 Department of Physical Education, Payame Noor University, Tehran, Iran

3 Mobility Impairment Research Center, Babol University of Medical Sciences, Iran

4 Clinical Research Department, Shahid Beheshti Hospital, Babol University of Medical Sciences, Babol, Iran

Abstract

Patellar tendon moment arm length (PTma) changes at different knee flexion angles have not been determined in in
vivo studies. We aimed to determine PTma in four different knee angles using Magnetic Resonance Imaging (MRI) to
predict in vivo changes in the moment arm length from different knee angles during running.
PTma was measured as the perpendicular distance from muscle–tendon line of action to the knee joint axis of rotation
at 0° (full extension), 20°, 40°, and 60° flexion of knee by using MRI method. Repeated measure ANOVA method was
applied to compare the moment arm length among four degrees of knee flexion (p <0.05). A regression analysis was
used to predict the PTma during different knee joint angles.
The PTma in the four angles at 0°, 20°, 40°, and 60° of knee flexion were 42.55±4.20, 39.91±2.98, 37.73±2.87, and
36.18±2.90 mm, respectively (p <0.05). The regression analysis provided an equation to predict the PTma from different
knee joint angles during running.
PTma values decreased from knee extension to flexion in a linear manner. These findings have important implications
for estimating PTma using a regression equation model from different knee joint angles.
Level of evidence: V

Keywords


1. Bai F, Chew CM. Muscle force estimation with surface
EMG during dynamic muscle contractions: A wavelet
and ANN based approach. In2013 35th Annual
International Conference of the IEEE Engineering
in Medicine and Biology Society (EMBC) 2013 (pp.
4589-4592). IEEE.
2. Fletcher JR, MacIntosh BR. Estimates of Achilles
tendon moment arm length at different ankle joint
angles: effect of passive moment. Journal of applied
biomechanics. 2018; 34(3):220-5.
3. Tsaopoulos DE, Baltzopoulos V, Richards PJ,
Maganaris CN. In vivo changes in the human patellar
tendon moment arm length with different modes
and intensities of muscle contraction. Journal of
biomechanics. 2007; 40(15):3325-32.
4. Spoor CW, Van Leeuwen JL. Knee muscle moment 
arms from MRI and from tendon travel. Journal of
biomechanics. 1992; 25(2):201-6.
5. Herzog W, Read LJ. Lines of action and moment arms
of the major force-carrying structures crossing the
human knee joint. Journal of anatomy. 1993; 182(Pt
2):213.
6. Krevolin JL, Pandy MG, Pearce JC. Moment arm of
the patellar tendon in the human knee. Journal of
biomechanics. 2004; 37(5):785-8.
7. Wretenberg P, Nemeth G, Lamontagne M, Lundin B.
Passive knee muscle moment arms measured in vivo
with MRI. Clinical Biomechanics. 1996; 11(8):439-46.
8. Nisell R, Németh G, Ohlsén H. Joint forces in extension
of the knee: analysis of a mechanical model. Acta
Orthopaedica Scandinavica. 1986; 57(1):41-6.
9. Tsaopoulos DE, Baltzopoulos V, Maganaris CN. Human 
patellar tendon moment arm length: measurement
considerations and clinical implications for joint
loading assessment. Clinical biomechanics. 2006;
21(7):657-67.
10. Fiorentino NM, Lin JS, Ridder KB, Guttman MA,
McVeigh ER, Blemker SS. Rectus femoris knee muscle
moment arms measured in vivo during dynamic
motion with real-time magnetic resonance imaging.
Journal of Biomechanical Engineering. 2013; 135(4).
11. Wilson NA, Sheehan FT. Dynamic in vivo
3-dimensional moment arms of the individual
quadriceps components. Journal of biomechanics.
2009; 42(12):1891-7.
12. Kellis E, Karagiannidis E, Patsika G. Patellar tendon
and hamstring moment-arms and cross-sectional
area in patients with anterior cruciate ligament
reconstruction and controls. Computer methods in
biomechanics and biomedical engineering. 2015;
18(10):1083-9.
13. Sheehan FT. The 3D patellar tendon moment arm:
quantified in vivo during volitional activity. Journal of
biomechanics. 2007; 40(9):1968-74.
14. Milanese S, Gordon S, Buettner P, Flavell C, Ruston
S, Coe D, et al. Reliability and concurrent validity of
knee angle measurement: smart phone app versus
universal goniometer used by experienced and novice
clinicians. Manual therapy. 2014; 19(6):569-74.
15. Tsaopoulos DE, Maganaris CN, Baltzopoulos V.
Can the patellar tendon moment arm be predicted
from anthropometric measurements? Journal of 
biomechanics. 2007; 40(3):645-51.
16. Buford WL, Ivey FM, Malone JD, Patterson RM, Pearce
GL, Nguyen DK, et al. Muscle balance at the kneemoment
arms for the normal knee and the ACLminus
knee. IEEE Transactions on Rehabilitation
Engineering. 1997; 5(4):367-79.
17. Gill HS, O’Connor JJ. Biarticulating two-dimensional
computer model of the human patellofemoral joint.
Clinical biomechanics. 1996; 11(2):81-9.
18. Visser JJ, Hoogkamer JE, Bobbert MF, Huijing PA.
Length and moment arm of human leg muscles as
a function of knee and hip-joint angles. European
journal of applied physiology and occupational
physiology. 1990; 61(5-6):453-60.
19. Bonnefoy A, Doriot N, Senk M, Dohin B, Pradon
D, Cheze L. A non-invasive protocol to determine
the personalized moment arms of knee and
ankle muscles. Journal of biomechanics. 2007;
40(8):1776-85.
20. Rugg SG, Gregor RJ, Mandelbaum BR, Chiu L. In vivo
moment arm calculations at the ankle using magnetic
resonance imaging (MRI). Journal of biomechanics.
1990; 23(5):495-501.
21. Ghourbanpour A, Talebi G.A, Hosseinzadeh S,
Janmohammadi N, Taghipour M. Effects of patellar
taping on knee pain, functional disability, and patellar
alignments in patients with patellofemoral pain
syndrome: A randomized clinical trial. Journal of
Bodywork and Movement Therapies. 2018; 22(2):
493-49