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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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External joint moments at the ankle, knee and hip in the sagittal plane at different phases of the ground contact phase while incline walking determined before (pre) and after (post) the triceps surae and quadriceps femoris muscle-tendon unit exercise-intervention (means and SE).The x-axis was normalized from 0 to 100% of a stride cycle. The vertical solid lines represent the instants of touchdown (TD) and take off (TO) of the left and right foot. DS: double support phase; SSL: single support phase of the analyzed left leg. *: Statistically significant differences between pre and post (P<0.05).
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pone-0099330-g002: External joint moments at the ankle, knee and hip in the sagittal plane at different phases of the ground contact phase while incline walking determined before (pre) and after (post) the triceps surae and quadriceps femoris muscle-tendon unit exercise-intervention (means and SE).The x-axis was normalized from 0 to 100% of a stride cycle. The vertical solid lines represent the instants of touchdown (TD) and take off (TO) of the left and right foot. DS: double support phase; SSL: single support phase of the analyzed left leg. *: Statistically significant differences between pre and post (P<0.05).

Mentions: A significant (P<0.05) intervention x time window effect was found for the external dorsiflexion-plantar flexion ankle joint moment (Fig. 2), and for all examined kinetic outcome measures in the frontal plane (moments at the ankle, knee and hip joint, lever arm of the GRF acting about the knee joint and mediolateral component of the GRF; Fig. 3 and Fig. 4). The simple contrast test showed that at post- in comparison to pre-intervention, the older adults had significantly (P<0.05) higher external ankle dorsiflexion moments in the terminal portion of the stance phase (effect size >0.4) but revealed no significant (P>0.05) intervention effects on sagittal plane ankle joint moments in the initial and mid portions of the stance phase (Fig. 2; Table S1 in File S1). Concerning the joint moments in the frontal plane, the older adults showed significantly (P<0.05) lower external ankle inversion moments (effect size >0.5) and lower external adduction moments at the knee and hip joints (effect size >0.7) in the initial and mid portions of the stance phase post-intervention (Fig. 3; Table S1–S3 in File S1). Furthermore, the external knee adduction angular impulse (calculated as the integral of the external knee adduction moment over the time of the stance phase) showed significantly (P<0.05) lower values following the MTU intervention (pre: 123.2±10.8 Nm kg−1 ms vs. post: 99.8±11.9 Nm kg−1 ms) with a pre/post effect size of 0.7.


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 joint moments at the ankle, knee and hip in the sagittal plane at different phases of the ground contact phase while incline walking determined before (pre) and after (post) the triceps surae and quadriceps femoris muscle-tendon unit exercise-intervention (means and SE).The x-axis was normalized from 0 to 100% of a stride cycle. The vertical solid lines represent the instants of touchdown (TD) and take off (TO) of the left and right foot. DS: double support phase; SSL: single support phase of the analyzed left leg. *: 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-g002: External joint moments at the ankle, knee and hip in the sagittal plane at different phases of the ground contact phase while incline walking determined before (pre) and after (post) the triceps surae and quadriceps femoris muscle-tendon unit exercise-intervention (means and SE).The x-axis was normalized from 0 to 100% of a stride cycle. The vertical solid lines represent the instants of touchdown (TD) and take off (TO) of the left and right foot. DS: double support phase; SSL: single support phase of the analyzed left leg. *: Statistically significant differences between pre and post (P<0.05).
Mentions: A significant (P<0.05) intervention x time window effect was found for the external dorsiflexion-plantar flexion ankle joint moment (Fig. 2), and for all examined kinetic outcome measures in the frontal plane (moments at the ankle, knee and hip joint, lever arm of the GRF acting about the knee joint and mediolateral component of the GRF; Fig. 3 and Fig. 4). The simple contrast test showed that at post- in comparison to pre-intervention, the older adults had significantly (P<0.05) higher external ankle dorsiflexion moments in the terminal portion of the stance phase (effect size >0.4) but revealed no significant (P>0.05) intervention effects on sagittal plane ankle joint moments in the initial and mid portions of the stance phase (Fig. 2; Table S1 in File S1). Concerning the joint moments in the frontal plane, the older adults showed significantly (P<0.05) lower external ankle inversion moments (effect size >0.5) and lower external adduction moments at the knee and hip joints (effect size >0.7) in the initial and mid portions of the stance phase post-intervention (Fig. 3; Table S1–S3 in File S1). Furthermore, the external knee adduction angular impulse (calculated as the integral of the external knee adduction moment over the time of the stance phase) showed significantly (P<0.05) lower values following the MTU intervention (pre: 123.2±10.8 Nm kg−1 ms vs. post: 99.8±11.9 Nm kg−1 ms) with a pre/post effect size of 0.7.

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