Effects of elliptical training on pain, motor function, muscle strength and knee joint kinetics during walking in people with knee osteoarthritis

Abstract

Effects of Elliptical Training on Pain, Motor Function, Muscle Strength and Knee Joint Kinetics During Walking in People with Knee Osteoarthritis

Max R. Paquette1, Audrey Zucker-Levin2, Paul DeVita3 and William Mihalko2

1 University of Memphis, Memphis, TN, USA
2 University of Tennessee Health Science Center, Memphis, TN, USA
3East Carolina University, Greenville, NC, USA

Knee osteoarthritis (OA) is a common, disabling disease in the elderly with many knee OA patients reporting poor quality of life (QOL). Both aerobic and anaerobic exercise programs have been effective at reducing pain and improving motor function, muscle strength, and QOL in knee OA patients [1] although few gait changes have been reported. Due to the overall success of various exercise programs, we hypothesized elliptical training would also reduce pain and improve motor function and QOL in knee OA patients. Due to its weight-bearing nature and previously reported increases in knee extensor muscle activity compared to level-walking, we also hypothesized that elliptical training would improve knee extensor muscle strength.
The purpose of this pilot study was to assess the effectiveness of a 6-week elliptical training intervention on knee pain, QOL, motor function, quadriceps strength, knee kinetics and gait kinematics in people with knee OA.
Three knee OA patients (2 women and 1 man) completed laboratory testing before and after six weeks of elliptical training (3 sessions/week). Knee pain and QOL during daily activities were assessed using the pain, and QOL subscales of the WOMAC questionnaire while motor function was assessed using the 6-minute walk (6MW), the timed-up and go (TUG), and the stair climb and descent (SCD) tests. Knee extensor muscle strength was measured using an isokinetic dynamometer. Motion capture and a force platform were used to collect 3D kinematics and ground reaction forces, respectively. An inverse dynamics method was used to calculate early stance peak internal knee abduction (KAM) and extension moments (KEM) during self-selected walking speed. Cohen’s D effect sizes (ES) were computed to compare means pre and post training.
The WOMAC pain and QOL subscales, 6MW, TUG, SCD and knee extensor strength were all improved following training (ES > 0.70). Despite small reductions in walking speed (ES=-0.23) and step length (ES=-0.37), KAM (ES=0.43) and KEM (ES=0.11) were slightly increased following elliptical training. The findings from this pilot study suggest that elliptical training may be effective for improving knee pain, QOL, motor function and knee extensor strength in knee OA patients. However, the moderate increase in KAM may suggest larger knee loads following elliptical training. These preliminary, beneficial effects of elliptical training support the contention that larger, randomized clinical trials with this exercise modality are justified.

Reference

Messier, S.P., S.L. Mihalko, C. Legault, G.D. Miller, B.J. Nicklas, P. DeVita, D.P. Beavers, D.J. Hunter, M.F. Lyles, F. Eckstein, J.D. Williamson, J.J. Carr, A. Guermazi, and R.F. Loeser, Effects of intensive diet and exercise on knee joint loads, inflammation, and clinical outcomes among overweight and obese adults with knee osteoarthritis: the IDEA randomized clinical trial. JAMA, 2013. 310(12): p. 1263-73.

Full text

Subjects
•Three medial compartment knee OA patients (2 women; 65.3±2.3 years)
participated in this study
Dependent Measures
•Knee pain and QOL during daily activities (WOMAC)
•Motor function with 6-minute walk (6MW), timed-up and go (TUG) and stair climb
and descent (SCD) tests
•Peak isokinetic knee extensor and hip abductor torque (Biodex)
•Peak internal knee abduction and extensor moments during
controlled self-selected level-walking.
Training
•Participants completed 6 weeks of elliptical training with three 45 minute
supervised sessions per week.
•The sessions consisted of five 5 minute elliptical exercise bouts: 1) warm-up, 2-4)
sub-maximal with slightly elevated intensity, 5) cool-down
Methods
Effects of elliptical training on pain, motor function, muscle strength and
knee joint kinetics during walking in people with knee osteoarthritis
References
1. Messier, S.P., et al. JAMA, 2013. 310(12): p. 1263-73.
2. Wortley, M., Journal of Sport and Health Science, 2013. In Press.
3. King, L.K., Med Sci Sports Exerc, 2008. 40(8): p. 1376-84.
4. Penedo, F.J. Curr Opin Psychiatry, 2005. 18(2): p. 189-93.
5. Salacinski, A.J., J Orthop Sports Phys Ther, 2012. 42(12): p. 985-95.
Results
Table 1. Functional mobility measures pre and post-training (mean±SD) with effect sizes (ES)
1University of Memphis, Health & Sport Sciences, Memphis, TN;
2University of Tennessee Health Science Center, Physical Therapy,
Memphis, TN; 3East Carolina University, Kinesiology, Greenville, NC
1Max R. Paquette, 2Audrey Zucker-Levin, 3Paul DeVita, 2William Mihalko
•Strength training is effective for improving lower extremity muscle strength,
mobility function and QOL [1,2], but has no positive training effects on gait
biomechanics in knee osteoarthritis (KOA) patients [3].
•Aerobic training (e.g. sub-maximal cycling) directly improves patient QOL [4], but
has little to no effect on muscle strength or gait biomechanics in KOA patients [5].
•Due to the overall success of various exercise programs, we hypothesized that
elliptical training would also reduce pain and improve motor function and QOL
and, improve knee extensor muscle strength in knee OA patients.
•The purpose of this pilot study was to assess the effectiveness of a 6-week
elliptical training intervention on knee pain, QOL, motor function, quadriceps
strength, knee kinetics and gait kinematics in people with knee OA.
Introduction
Contact: mrpqette@memphis.edu
Conclusion
•The findings from this pilot study suggest that elliptical training may be effective
for improving knee pain, QOL, motor function and knee extensor strength in knee
OA patients.
•However, the moderate increase in KAM may suggest larger knee loads following
elliptical training during level-walking.
•These preliminary, beneficial effects of elliptical training support the contention
that larger, randomized clinical trials with this exercise modality are justified.
PRE POST ES Outcome
Speed (m/s) 1.15 ± 0.27 1.09 ± 0.27 0.23 N/A
Step length (m) 0.60 ± 0.09 0.57 ± 0.08 0.37 N/A
WOMAC Pain (/20) 5.67 ± 4.93 2.67 ± 2.52 0.94 Improvement
WOMAC ADLs (/68)
21.0 ± 17.8 11.0 ± 9.6 0.86 Improvement
6MW (m) 388.5 ± 138.4 495.9 ± 59.7 1.23 Improvement
SCD (s) 21.1 ± 14.0 13.0 ± 1.4 1.00 Improvement
TUG (s) 8.1 ± 0.98 7.5 ± 0.5 1.01 Improvement
Figure 1: Peak isokinetic extensor and
abductor torques at 60 °/s (mean±SD) Figure 2: Peak knee abduction and
extension moments during gait (mean±SD)
Gait video
in V3D Elliptical Training
Video