Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access |

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc |

Journal website http://www.jocmr.org |

Original Article

Volume 05, Number 3, June 2013, pages 205-216

**The Effect of Whole Body Vibration Exposure on Muscle Function in Children With Cystic Fibrosis: A Pilot Efficacy Trial**

Figures

Tables

Week | Training frequency (days/week) | Vibration frequency (Hz) | Peak-to-Peak Vibration amplitude (mm) | Vibration magnitude (g)* | Total session duration (mins) | Vibration exposure (mins) |
---|---|---|---|---|---|---|

* Formula for vibration magnitude [40]: g = A (2πf)^{2}/9.81, A: Peak-to-Peak Vibration amplitude (mm); f: frequency (H_{z}); 9.81 = force due to gravity. | ||||||

5 | 3 | 20 | 1 | 1.61 | 20 | 10 |

6 | 3 | 20 | 1 | 1.61 | 30 | 15 |

7 | 3 | 22 | 1 | 1.95 | 30 | 15 |

8 | 3 | 22 | 1 | 1.95 | 30 | 15 |

Characteristic | Baseline (n = 7) |
---|---|

Values are mean ± standard deviations (SD); cm = centimetre; ml = millimetres; min = minute; kg = kilogram; cm = centimetre; m = metre; N = Newtons; Nm, Newton-metres; W = watts; % pred = value reported as percent of predicted value, 1RM = one repetition maximum; CFQ-R = cystic fibrosis questionnaire revised, where higher scores indicate better quality of life [10]; FEV_{1} = forced expiratory volume in 1 second; FVC = forced vital capacity; VC = vital capacity; RV = residual volume; TLC = total lung capacity; VO_{2}peak = peak oxygen uptake during volitional maximum treadmill test; OUES = oxygen uptake efficiency slope; higher OUES is associated with higher aerobic capacity [31]. | |

Age | 11.7 ± 2.6 |

Sex | 60% girls |

Anthropometry | |

Height (cm) | 146.2 ± 17.7 |

Weight (kg) | 40.8 ± 16.3 |

BMI (kg/m^{2}) | 18.3 ± 3.0 |

Waist circumference (cm) | 67.5 ± 8.3 |

Health-Related Quality of Life | |

Total score on CFQ-R (%) [12] (0 - 100) | 83.5 |

Respiratory function (% of predicted) | |

FEV_{1} | 77.4 ± 14.4 |

FVC | 88.0 ± 16.4 |

VC | 93.2 ± 13.6 |

RV | 125.3 ± 92.8 |

TLC | 99.7 ± 16.0 |

Aerobic Capacity | |

VO_{2} peak (ml/kg/min) | 34.5 ± 5.1 |

OUES [31] | 706.4 ± 281.7 |

Physical Performance | |

Countermovement jump height (cm) | 27.0 ± 5.0 |

Countermovement jump power (W) | 652.0 ± 306.0 |

Leg Extension strength (Nm) | 86 ± 37 |

Chest Press strength (N) | 213 ± 82 |

Leg Press strength (N) | 816 ± 168 |

Leg Extension peak power (W) | 199 ± 103 |

Chest Press peak power (W) | 138 ± 66 |

Leg Press peak power (W) | 473 ± 247 |

Outcome variable | Baseline | Pre WBV | Post WBV | Final | P value† | Effect Size 95% CI(lower, upper) | Post vs Final P value‡ |
---|---|---|---|---|---|---|---|

Values are mean ± standard deviations; Participants (WBV = 6); Effect sizes (ES) [32] were calculated as: Post testmean-pre testmean/pre SD for each of the time periods; CI = confidence interval; cm = centimetre; kg = kilogram; BMI = body mass index (kg/m^{2}); Nm = Newton metres; N = Newtons; W = Watts; ml = millimetres; CP = chest press; LE = leg extension; LP = leg press;VO_{2}peak = maximum oxygen uptake; OUES = oxygen uptake efficiency slope, higher values associated with higher aerobic capacity [31]; FEV_{1} = forced expiratory volume in 1 second; FVC = forced vital capacity; FEF_{25-75%} = forced mid-expiratory flow rate; Higher OUES = higher aerobic capacity; CFQ-R = Cystic Fibrosis Questionnaire-Revised, a disease-specific health-related quality of life questionnaire; higher values reflect better quality of life [10]. Normalised values are calculated as absolute strength or power/body weight in kg. *P < 0.05; † Repeated Measures ANOVA of baseline, pre, post timepoints only; ‡ paired t test to compare post and final timepoint. | |||||||

Muscle Strength | |||||||

LE strength(Nm) | 80.2 ± 37 | 80.2 ± 48.2 | 97.0 ± 66 | 92.7 ± 58.4 | 0.16 | 0.27 (-0.87, 1.41) | 0.46 |

LE relative strength (Nm/kg) | 2.0 ± 0.3 | 1.88 ± 0.4 | 2.2 ± 0.5 | 2.1 ± 0.4 | 0.14 | 0.66 (-0.50, 1.82) | 0.51 |

CP strength (N) | 201.0 ± 82.9 | 199.0 ± 86 | 222.3 ± 109.3 | 220.3 ± 104.9 | 0.06 | 0.22 (-0.92, 1.35) | 0.81 |

CP relative strength (N/kg) | 5.1 ± 0.6 | 4.90 ± 0.6 | 5.3 ± 0.3 | 5.3 ± 0.5 | 0.10 | 0.92 (-0.27, 2.11) | 0.79 |

LP strength (N) | 831.2 ± 197.5 | 838.0 ± 212.7 | 938.8 ± 320.4 | 908 ± 331.2 | 0.30 | 0.33 (-0.91, 1.58) | 0.56 |

LP relative strength (N/kg) | 21.3 ± 5.6 | 21.0 ± 4.9 | 22.9 ± 4.9 | 22.1 ± 5.1 | 0.40 | 0.36 (-0.89, 1.61) | 0.49 |

Muscle Power | |||||||

LE peak power (W) | 189.7 ± 108.7 | 196.7 ± 124.1 | 222.7 ± 162.2 | 220.3 ± 174.4 | 0.15 | 0.17 (-0.97, 1.30) | 0.82 |

LE relative peak power (W/kg) | 4.5 ± 0.8 | 4.5 ± 0.9 | 4.9 ± 1.4 | 5.0 ± 1.1 | 0.14 | 0.33 (-0.81, 1.47) | 0.93 |

CP peak power (W) | 132.0 ± 70.4 | 132.3 ± 69.1 | 133.3 ± 65.4 | 137.5 ± 74.1 | 0.52 | 0.01 (-1.12, 1.15) | 0.53 |

CP relative peak power (W/kg) | 3.2 ± 0.6 | 3.1 ± 0.6 | 3.2 ± 0.7 | 3.2 ± 0.5 | 0.97 | 0.06 (-1.07, 1.19) | 0.98 |

LP peak power (W) | 470.6 ± 288.7 | 469.2 ± 224.8 | 523.6 ± 251.4 | 519.6 ± 332 | 0.59 | 0.21 (-1.04, 1.45) | 0.96 |

LP relative peak power (W/kg) | 10.7 ± 2.1 | 10.7 ± 1.6 | 11.9 ± 1.4 | 9.5 ± 4.1 | 0.48 | 0.78 (-0.50, 2.07) | 0.26 |

Counter-movement Jump (CMJ) Performance | |||||||

Height (cm) | 26.3 ± 5.2 | 25.2 ± 4.7 | 27.8 ± 3.4 | 26.3 ± 3.3 | 0.11 | 0.60 (-0.56, 1.76) | 0.17 |

Peak power (W) | 634.2 ± 331.8 | 673.4 ± 375.1 | 721.4 ± 425.8 | 715.5 ± 427.3 | 0.13 | 0.11 (-1.02, 1.24) | 0.77 |

Relative peak power (W/kg) | 15.4 ± 2.2 | 16.1 ± 3.7 | 16.8 ± 2.4 | 167.0 ± 2.7 | 0.39 | 0.19 (-0.95, 1.32) | 0.86 |

Peak Aerobic Capacity | |||||||

VO_{2}peak (ml/kg/min) | 32.3 ± 4.1 | 38.7 ± 5 | 35.6 ± 4.7 | 36.6 ± 2.6 | 0.16 | -0.61 (-1.76, 0.55) | 0.69 |

OUES | 706.4 ± 281.7 | 953.8 ± 280.5 | 866.8 ± 272 | 840.1 ± 331.5 | < 0.01 | -0.28 (-1.53, 0.96) | 0.62 |

Respiratory function | |||||||

FEV1 (%) | 75 ± 14.1 | 80.2 ± 9.5 | 78.0 ± 7.5 | - | 0.47 | -0.23 (-1.37, 0.90) | - |

FVC (%) | 85.5 ± 16.5 | 91.83 ± 11.0 | 89.0 ± 7.6 | - | 0.49 | -0.28 (-1.41, 0.86) | - |

FEF_{25-75%} | 64.7 ± 24 | 68.83 ± 22.2 | 66.0 ± 15.8 | - | 0.70 | -0.14 (-1.27, 1.00) | - |

CFQ-R | 84.5 ± 7.3 | 83.3 ± 9.0 | 81.0 ± 11.5 | - | 0.37 | -0.20 (-1.33, 0.94) | - |

Main outcomes | Effect Size | Total sample size required (n) |
---|---|---|

*G-power software (GPower 3.0 for Windows, Germany) used to compute sample size necessary to achieve statistical significance assuming and two-sided alpha of 0.05 and a beta of 0.20. Sample size assumes a 2-group design, with equal 1:1 allocation to each group. Power calculations were performed for the 4 variables with the largest Effect Sizes observed in this pilot study. | ||

LE relative strength (Nm/kg) | 0.66 (-0.50, 1.82) | 10 |

CP relative strength (N/kg) | 0.92 (-0.27, 2.11) | 9 |

LP relative peak power (W/kg) | 0.78 (-0.50,2.07) | 12 |

Counter-movement jumpheight (cm) | 0.60 (-0.56, 1.76) | 18 |