EQUINE VETERINARY EDUCATION / AE / SEPTEMBER 2017
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5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
Horse A1
T15-16 T16-17 T18-L1 L1-2 Horse A4
5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
T15-16 T16-17 T18-L1 L1-2 Horse B3
5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
T15-16 T16-17 T18-L1 L1-2
5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
Horse A2
T15-16 T16-17 T18-L1 L1-2 Horse B1
5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
T15-16 T16-17 T18-L1 L1-2 Horse B4
5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
T15-16 T16-17 T18-L1 L1-2 Spinal region
5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
Horse A3
T15-16 T16-17 T18-L1 L1-2 Horse B2
T15-16 T16-17 T18-L1 L1-2 Horse B5
T15-16 T16-17 T18-L1 L1-2
Fig 3: The bar graphs display the m. multifidus CSA (cm2) of each participant at each individual spinal regions for each of the three assessment periods (Days 0, 30 and 60). Each bar represents the average cross-sectional areas of left and right m. multifidus (mean s.d.) at four thoracolumbar levels in nine horses on Days 0, 30 and 60 of whole body vibration (WBV) treatment.
muscle activation by WBV seems to be frequency dependent, with maximum activation of MFT-I fibres occurring at lower frequencies than for MFT-II fibres (Lochy 2013).
nski et al. We assumed that a 60-day WBV protocol would be long
enough for a muscle change to occur. This was based on the fact that in man 8–10 week WBV protocols are able to improve muscle CSA (Belav
y et al. 2008; Machado et al.
2009) and in mice as little as 6 weeks (Xie et al. 2008). Whole body vibration training has been reported as being similar to resistance training (Bosco et al. 1998), with protein synthesis, a precursor for muscle hypertrophy, occurring after one resistance training session and changes in muscle size occurring after 4–6 weeks of resistance training (Gabriel et al. 2006). In horses specifically, significant muscle hypertrophy has been observed after a 2-month progressive training
programme in unconditioned horses and changes in muscle fibre composition was noticed after short-term (3 weeks) specific training protocols in pretrained horses (Rivero et al. 2007).
The increase in the m. multifidus CSA seen after only 30 days is relatively fast. This could be related to the
immediate increase in muscle CSA seen post-exercise, which is well established in man and further supported by a more recent study in horses showing that a transient exercise- induced increase in back dimensions takes place (Greve et al. 2015). Although the mechanism of action responsible for a post exercise-induced increase in muscle CSA is not clear, one possible explanation is that the initial increase in muscle CSA is related to an increase in muscle fluid content rather than true hypertrophy secondary to increase in size and/or numbers of the contractile proteins (actin and myosin). This is supported by research in man, showing that an increase in muscle CSA is seen post-exercise secondary to extravascular fluid accumulation linked to muscle activity and perfusion (Nygren and Kaijser 2002). However, it is possible that the increase in CSA is related to a true muscle hypertrophy. A change in muscle fibre composition is readily seen after 3 weeks of specific training in pretrained horses (Rivero et al. 2007); the horses used in this study were pretrained and thus are likely to have been able to demonstrate a change in muscle fibre composition. Alteration in fibre size is easier achieved than a transformation (shift) from one muscle fibre type to another (Goldspink 1985),
© 2016 EVJ Ltd
m. multifidus CSA(cm2)
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