Muscle Fuel Symmetry - MFS
- Assesses the symmetry (balance) of MuscleSound scores between contralateral (dominant and nondominant) muscles of the upper or lower body
- Reported as a percent lower than the muscle with higher fuel values,
- No side difference would result in a 0% lower value.
- The maximum side difference would result in one side’s displaying -100% lower.
- Asymmetric differences in strength and power output levels between dominant and nondominant limbs have been reported in professional athletes.
- Such differences have been linked to increased injury risk and performance deficits.
- To date, these differences have been assessed and reported in Isokinetic, biomechanical, strength, power or field test measures.
- The Fuel status of a muscle contributes significantly to the strength and force of its contraction.
- MFS can act as a surrogate for these traditional measures, and used as an easily obtained early warning of potential injury risk for coaches and/or nutritionists .
- An additional and highly convenient tool that can provide early indications of potential injury risk.
- By utilizing the MFS assessment, potential strength/power deficits may be quickly screened, and a much earlier determination can be made as to the need for further testing.
- Can be applied to rehab as well as performance and training situations. NOTE: Inadequate rehabilitation and premature return to play after injury have been suggested risk factors for recurrence of injury.
- Can be used to develop and monitor training routines designed to reduce observed deficits.
- Can be used to identify and report trends in improvements over time.
- From our database, calculate the biggest contralateral difference in MuscleSound scores between pairs of muscles from the same ultrasound model. NOTE: Different ultrasound models produce different scores for the same muscle.
- The largest contralateral difference in our database is represented as a 100% difference in symmetry.
- Calculate the difference between the two individual values for each muscle pair in this session.
- Compare this difference value to the maximum difference found in the database.
- Calculate the symmetry score for the lower scoring side as a percentage of the higher scoring side.
- No side difference would result in perfect symmetry or 0% difference.
- The maximum difference would result in one side being 100% lower than the other.
Assume the raw image value for each side of a particular muscle is 47.58 (For the left side muscle) and 46.11 (for the right side muscle).
- Find the difference between Left and Right sides
- Difference = 47.58 - 46.11 = 1.47
- The largest difference between sides for this muscle with this ultrasound device is 8.64
- Percent difference = (1.47 / 8.64) x 100 = 17%
- This would be presented as the Right is 17% lower than the Left
- Brughelli, M, Cronin, J, Mendiguchia, J, Kinsella, D, and Nosaka, K. Contralateral leg deficits in kinetic and kinematic variables during running in Australian rules football players with previous hamstring injuries. J Strength Cond Res 24(9): 2539–2544, 2010
- Keeley, DW, Plummer, HA, and Oliver, GD. Predicting asymmetrical lower extremity strength deficits in college aged men and women using common horizontal and vertical power field tests: A possible screening mechanism. J Strength Cond Res 25(6): 1632–1637, 2011
- Croisier, J-L., Ganteaume, S., Binet, J., Genty, M., and Ferret, J-M. Strength Imbalances and Prevention of Hamstring Injury in Professional Soccer Players. The American Journal of Sports Medicine 36(8):1469-1475, 2008
- Hamilton, RT, Shultz, SJ, Schmidt, RJ, and Perrin, DH. Triple-hop distance as a valid predictor of lower limb strength and power. J Athl Train 43: 144–151, 2008.