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Effect of exercise-induced enhancement of the leg-extensor muscle-tendon unit capacities on ambulatory mechanics and knee osteoarthritis markers in the elderly.

Karamanidis K, Oberländer KD, Niehoff A, Epro G, Brüggemann GP - PLoS ONE (2014)

Bottom Line: Furthermore, post-intervention compared to pre-intervention, the elderly showed lower external hip adduction moment, but revealed higher plantarflexion pushoff moment.The changes in the external knee adduction moment were significantly correlated with the improvement in ankle pushoff function.This work emphasizes the important role played by the ankle pushoff function in knee joint mechanical loading during locomotion, and may justify the inclusion of the TS MTU in prevention programs aiming to positively influence specific mechanical markers for knee osteoarthritis in the elderly.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biomechanics and Orthopaedics, German Sport University of Cologne, Cologne, Germany; Department of Mathematics and Technology, University of Applied Sciences Koblenz, RheinAhrCampus Remagen, Koblenz, Germany.

ABSTRACT

Objective: Leg-extensor muscle weakness could be a key component in knee joint degeneration in the elderly because it may result in altered muscular control during locomotion influencing the mechanical environment within the joint. This work aimed to examine whether an exercise-induced enhancement of the triceps surae (TS) and quadriceps femoris (QF) muscle-tendon unit (MTU) capacities would affect mechanical and biological markers for knee osteoarthritis in the elderly.

Methods: Twelve older women completed a 14-week TS and QF MTU exercise intervention, which had already been established as increasing muscle strength and tendon stiffness. Locomotion mechanics and serum cartilage oligomeric matrix protein (COMP) levels were examined during incline walking. MTU mechanical properties were assessed using simultaneously ultrasonography and dynamometry.

Results: Post exercise intervention, the elderly had higher TS and QF contractile strength and tendon-aponeurosis stiffness. Regarding the incline gait task, the subjects demonstrated a lower external knee adduction moment and lower knee adduction angular impulse during the stance phase post-intervention. Furthermore, post-intervention compared to pre-intervention, the elderly showed lower external hip adduction moment, but revealed higher plantarflexion pushoff moment. The changes in the external knee adduction moment were significantly correlated with the improvement in ankle pushoff function. Serum COMP concentration increased in response to the 0.5-h incline walking exercise with no differences in the magnitude of increment between pre- and post-intervention.

Conclusions: This work emphasizes the important role played by the ankle pushoff function in knee joint mechanical loading during locomotion, and may justify the inclusion of the TS MTU in prevention programs aiming to positively influence specific mechanical markers for knee osteoarthritis in the elderly. However, the study was unable to show that COMP is amenable to change in the elderly following a 14-week exercise intervention and, therefore, the physiological benefit of improved muscle function for knee cartilage requires further investigation.

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Related in: MedlinePlus

External knee adduction angular impulse during the stance phase while incline walking for the 12 intervention subjects and the 4 control subjects measured before (PRE) and after (POST) the 14-week exercise duration, with line of equality.The plot illustrates that the degree of agreement in the external knee adduction impulse between pre and post measurements was higher for the control group than for the intervention group.
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pone-0099330-g007: External knee adduction angular impulse during the stance phase while incline walking for the 12 intervention subjects and the 4 control subjects measured before (PRE) and after (POST) the 14-week exercise duration, with line of equality.The plot illustrates that the degree of agreement in the external knee adduction impulse between pre and post measurements was higher for the control group than for the intervention group.

Mentions: A major limitation of this study is the lack of a control group. We originally started the empirical study with 26 older women (15 subjects in the intervention group and 11 subjects in the control group). Unfortunately, for a variety of reasons, a relatively large number of women in the control group dropped out during the 14-week period. Only four older women successfully completed all measurements and we therefore decided not to include the control group in our statistics. However, when considering the individual data of these four older women, we can suggest that the degree of agreement in gait characteristics between pre and post measurements was reasonably high. Exemplarily, in figure 7 we plotted the external knee adduction impulse using the individual data of the four control and the 12 intervention subjects and drew the line of equality on which all points would lie if the two meters gave exactly the same reading every time. The plot shows that the degree of agreement in the external knee adduction impulse between pre and post measurements was clearly higher for the control group than for the intervention group (Fig. 7). Moreover, for the external knee adduction moment the effect size within the intervention group was up to 1 of the standard deviation indicating that the magnitude of the difference between pre and post measurement was large. Additional studies are needed to examine the effectiveness of an exercise-induced enhancement in TS and QF contractile strength and tendon-aponeurosis stiffness in the elderly and to confirm that such gait improvements can be attributed predominantly to the training regime.


Effect of exercise-induced enhancement of the leg-extensor muscle-tendon unit capacities on ambulatory mechanics and knee osteoarthritis markers in the elderly.

Karamanidis K, Oberländer KD, Niehoff A, Epro G, Brüggemann GP - PLoS ONE (2014)

External knee adduction angular impulse during the stance phase while incline walking for the 12 intervention subjects and the 4 control subjects measured before (PRE) and after (POST) the 14-week exercise duration, with line of equality.The plot illustrates that the degree of agreement in the external knee adduction impulse between pre and post measurements was higher for the control group than for the intervention group.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4048280&req=5

pone-0099330-g007: External knee adduction angular impulse during the stance phase while incline walking for the 12 intervention subjects and the 4 control subjects measured before (PRE) and after (POST) the 14-week exercise duration, with line of equality.The plot illustrates that the degree of agreement in the external knee adduction impulse between pre and post measurements was higher for the control group than for the intervention group.
Mentions: A major limitation of this study is the lack of a control group. We originally started the empirical study with 26 older women (15 subjects in the intervention group and 11 subjects in the control group). Unfortunately, for a variety of reasons, a relatively large number of women in the control group dropped out during the 14-week period. Only four older women successfully completed all measurements and we therefore decided not to include the control group in our statistics. However, when considering the individual data of these four older women, we can suggest that the degree of agreement in gait characteristics between pre and post measurements was reasonably high. Exemplarily, in figure 7 we plotted the external knee adduction impulse using the individual data of the four control and the 12 intervention subjects and drew the line of equality on which all points would lie if the two meters gave exactly the same reading every time. The plot shows that the degree of agreement in the external knee adduction impulse between pre and post measurements was clearly higher for the control group than for the intervention group (Fig. 7). Moreover, for the external knee adduction moment the effect size within the intervention group was up to 1 of the standard deviation indicating that the magnitude of the difference between pre and post measurement was large. Additional studies are needed to examine the effectiveness of an exercise-induced enhancement in TS and QF contractile strength and tendon-aponeurosis stiffness in the elderly and to confirm that such gait improvements can be attributed predominantly to the training regime.

Bottom Line: Furthermore, post-intervention compared to pre-intervention, the elderly showed lower external hip adduction moment, but revealed higher plantarflexion pushoff moment.The changes in the external knee adduction moment were significantly correlated with the improvement in ankle pushoff function.This work emphasizes the important role played by the ankle pushoff function in knee joint mechanical loading during locomotion, and may justify the inclusion of the TS MTU in prevention programs aiming to positively influence specific mechanical markers for knee osteoarthritis in the elderly.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biomechanics and Orthopaedics, German Sport University of Cologne, Cologne, Germany; Department of Mathematics and Technology, University of Applied Sciences Koblenz, RheinAhrCampus Remagen, Koblenz, Germany.

ABSTRACT

Objective: Leg-extensor muscle weakness could be a key component in knee joint degeneration in the elderly because it may result in altered muscular control during locomotion influencing the mechanical environment within the joint. This work aimed to examine whether an exercise-induced enhancement of the triceps surae (TS) and quadriceps femoris (QF) muscle-tendon unit (MTU) capacities would affect mechanical and biological markers for knee osteoarthritis in the elderly.

Methods: Twelve older women completed a 14-week TS and QF MTU exercise intervention, which had already been established as increasing muscle strength and tendon stiffness. Locomotion mechanics and serum cartilage oligomeric matrix protein (COMP) levels were examined during incline walking. MTU mechanical properties were assessed using simultaneously ultrasonography and dynamometry.

Results: Post exercise intervention, the elderly had higher TS and QF contractile strength and tendon-aponeurosis stiffness. Regarding the incline gait task, the subjects demonstrated a lower external knee adduction moment and lower knee adduction angular impulse during the stance phase post-intervention. Furthermore, post-intervention compared to pre-intervention, the elderly showed lower external hip adduction moment, but revealed higher plantarflexion pushoff moment. The changes in the external knee adduction moment were significantly correlated with the improvement in ankle pushoff function. Serum COMP concentration increased in response to the 0.5-h incline walking exercise with no differences in the magnitude of increment between pre- and post-intervention.

Conclusions: This work emphasizes the important role played by the ankle pushoff function in knee joint mechanical loading during locomotion, and may justify the inclusion of the TS MTU in prevention programs aiming to positively influence specific mechanical markers for knee osteoarthritis in the elderly. However, the study was unable to show that COMP is amenable to change in the elderly following a 14-week exercise intervention and, therefore, the physiological benefit of improved muscle function for knee cartilage requires further investigation.

Show MeSH
Related in: MedlinePlus