Whole-Body Vibration Induced Adaptation in Knee Extensors; Consequences of Initial Strength, Vibration Frequency, and Joint Angle

Savelberg, Hans; Keizer, H. A.; Meijer, K.

doi:10.1519/00124278-200705000-00052

Cited by 11 publications

(16 citation statements)

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“…Under MomT-forced-L the extending knee-joint moment was 185 Nm. Maximal isometric strength of this muscle group for a similar population has been reported to be at about the same level [18].…”

Section: Discussionmentioning

confidence: 67%

Muscles limiting the sit-to-stand movement

et al. 2009

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Adapted strategies in rising from a chair occur with muscle weakness. To assess whether muscle weakness caused the strategy change, an experimental simulation was performed that allowed to investigate separately effects of reduced muscle capacity and of strategy change on movement dynamics. It was hypothesized that a sit-to-stand (STS) strategy change spares muscles that become overloaded when muscle weakness develops. Ten healthy females participated; seven of them completed all tests. Muscle weakness causes an increased load-over-capacity ratio. In the present study, this ratio was increased by providing participants with a waist-coat containing 45% of their body mass. Participants performed sit-to-stand manoeuvres with and without added mass; moreover they were instructed to perform two different strategies, the moment-transfer-strategy and the stabilization-strategy. During these STS-tasks sagital 2D-video analysis were made and ground reaction forces (GRF) were measured. Joint moments and powers for ankle, knee and hip joint were calculated. The preferred strategy under the normal condition was the moment-transfer strategy. Increasing the load without adapting the strategy resulted in significantly higher (13%) knee-joint extension moments. Allowing a strategy shift in the loaded condition spared the knee-joint extensors (-6%) and transferred effort to hip-joint extensors (57%) and plantar flexor (67%) muscles. These results suggest that the capacity of knee-joint extensors limits the STS-performance when muscle weakness occurs.

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Section: Discussionmentioning

confidence: 67%

Muscles limiting the sit-to-stand movement

et al. 2009

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“…Research has found that it increases lower limb muscular strength (Torvinen et al 2002) and power (Bosco et al 1999;Cardinale and Lim 2003;Da Silva et al 2006), whereas other work has shown that it shifts the ankle or knee angle at which peak torque is produced (Kemertzis et al 2008;Savelberg et al 2007). Kemertzis et al, for example, found human ankle plantar flexors (placed in full stretch) respond to WBV by shifting the point of peak voluntary torque production towards a longer muscle length.…”

Section: Introductionmentioning

confidence: 99%

Voluntary activation of the ankle plantar flexors following whole-body vibration

et al. 2009

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This study investigated the effect of whole-body vibration (WBV) on the voluntary activation of the ankle plantar flexors. Twelve healthy young adults were randomly exposed to two treatments on separate occasions. The first (non-WBV) involved stretching of the plantar flexors at end range of dorsiflexion for five 1-min bouts. The second involved the same stretch with WBV (26 Hz) for five 1-min bouts. Attempted maximal voluntary contractions (AMVCs) of the plantar flexors were performed on an isokinetic dynamometer (30 degrees s(-1)) before and after each treatment. A twitch interpolation technique was used to investigate voluntary activation. Post-treatment data were normalised against pre-treatment data. Subjects were classified as maximally (n = 6) or sub-maximally (n = 6) activated using the pre-treatment twitch interpolation data. The effects of WBV were assessed by repeated measure (RM) MANOVA. After WBV, the group of subjects classified as sub-maximally activated increased peak voluntary torque and rate of voluntary torque production (P < 0.05), whereas angular displacement to peak torque reduced (P < 0.05); i.e. peak torque was produced at a longer muscle length. No significant non-WBV treatment effects were found for this group. No significant WBV effects were found for the group of subjects classified as maximally activated. This study found that the response to WBV was dependent on the level of voluntary activation of the ankle plantar flexors during a set of AMVCs.

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“…Whole-body vibration (WBV) is a fairly new method to increase muscle strength and power in healthy humans (Bosco et al, 1998;Mahieu et al, 2006;Paradisis and Zacharogiannis, 2007;Savelberg et al, 2007;Colson et al, 2010). After short-term training programs lasting 6 weeks or less, maximal voluntary isometric (Savelberg et al, 2007;Colson et al, 2010) and concentric (Mahieu et al, 2006) muscle strength was reported to be improved, particularly for knee extensor muscles, which are most often analyzed.…”

Section: Introductionmentioning

confidence: 99%

“…After short-term training programs lasting 6 weeks or less, maximal voluntary isometric (Savelberg et al, 2007;Colson et al, 2010) and concentric (Mahieu et al, 2006) muscle strength was reported to be improved, particularly for knee extensor muscles, which are most often analyzed. In addition, substantial and significant gains in muscle power, generally assessed by means of vertical jump performance, were achieved within this training duration (Bosco et al, 1998;Rønnestad, 2004;Paradisis and Zacharogiannis, 2007;Wyon et al, 2010).…”

Section: Introductionmentioning

confidence: 99%