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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

Tendon-aponeurosis strain of the gastrocnemius medialis (TSMTU) and vastus lateralis (QFMTU) at every 200 N of the calculated Achilles and patella tendon force during isometric maximal voluntary ankle plantarflexion and knee extension contractions determined before (pre) and after (post) the triceps surae and quadriceps femoris muscle-tendon unit exercise-intervention (means and SE).*: Statistically significant differences between pre and post (P<0.05).
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pone-0099330-g001: Tendon-aponeurosis strain of the gastrocnemius medialis (TSMTU) and vastus lateralis (QFMTU) at every 200 N of the calculated Achilles and patella tendon force during isometric maximal voluntary ankle plantarflexion and knee extension contractions determined before (pre) and after (post) the triceps surae and quadriceps femoris muscle-tendon unit exercise-intervention (means and SE).*: Statistically significant differences between pre and post (P<0.05).

Mentions: With regard to the contractile strength, the examined subjects showed significantly (P<0.05) higher maximal isometric ankle plantarflexion (pre: 2.01±0.13 Nm kg−1vs. post: 2.28±0.12 Nm kg−1) and knee extension joint moments (2.28±0.08 Nm kg−1vs. 2.49±0.09 Nm kg−1) following the intervention. For a given tendon force (every 200 N), the strain values of the TS and QF tendon and aponeurosis were significantly (P<0.05) lower post- compared to pre-intervention (Fig. 1). Thus, as for the gains in the contractile strength, post-intervention normalized tendon stiffness was significantly higher (P<0.05) for both MTUs compared to pre-intervention (TS: 51.4±3.8 kN strain−1vs. 62.4±3.6 kN strain−1; QF: 76.5±5.1 kN strain−1vs. 89.9±4.8 kN strain−1).


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)

Tendon-aponeurosis strain of the gastrocnemius medialis (TSMTU) and vastus lateralis (QFMTU) at every 200 N of the calculated Achilles and patella tendon force during isometric maximal voluntary ankle plantarflexion and knee extension contractions determined before (pre) and after (post) the triceps surae and quadriceps femoris muscle-tendon unit exercise-intervention (means and SE).*: Statistically significant differences between pre and post (P<0.05).
© Copyright Policy
Related In: Results  -  Collection

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

pone-0099330-g001: Tendon-aponeurosis strain of the gastrocnemius medialis (TSMTU) and vastus lateralis (QFMTU) at every 200 N of the calculated Achilles and patella tendon force during isometric maximal voluntary ankle plantarflexion and knee extension contractions determined before (pre) and after (post) the triceps surae and quadriceps femoris muscle-tendon unit exercise-intervention (means and SE).*: Statistically significant differences between pre and post (P<0.05).
Mentions: With regard to the contractile strength, the examined subjects showed significantly (P<0.05) higher maximal isometric ankle plantarflexion (pre: 2.01±0.13 Nm kg−1vs. post: 2.28±0.12 Nm kg−1) and knee extension joint moments (2.28±0.08 Nm kg−1vs. 2.49±0.09 Nm kg−1) following the intervention. For a given tendon force (every 200 N), the strain values of the TS and QF tendon and aponeurosis were significantly (P<0.05) lower post- compared to pre-intervention (Fig. 1). Thus, as for the gains in the contractile strength, post-intervention normalized tendon stiffness was significantly higher (P<0.05) for both MTUs compared to pre-intervention (TS: 51.4±3.8 kN strain−1vs. 62.4±3.6 kN strain−1; QF: 76.5±5.1 kN strain−1vs. 89.9±4.8 kN strain−1).

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