Muscle Strength And Bio Impedance Analysis

AANT316 Elena Gomez

Paper 2 Muscle Physiology: Muscle strength and its relationship with skeletal muscle mass

Introduction

The Alizadehkhaiyat et al (2013) article aimed to find the relationship between muscle strength and segmented skeletal muscle mass through the use of bio-impedance analysis as well as the effects of gender on this relationship. Bio-impedance analysis measures how the body tissues impede electric current flow through the use of electrode configuration. Lean tissues are good conducers and fat tissues are not due to the different water compositions of each tissue (water conduces electricity). 22 healthy males and 23 healthy females participated in the study with a mean age of 30.3 years old. The muscle strength

The individuals were barefoot and wore light clothing for height and body weight measurements to ensure accuracy. The body mass index was calculated by dividing the individual's body weight by their height squared. The length of the arm and torso were measured to the closest 0.5 cm to calculate the skeletal muscle mass. This can be found using an integrated bio-impedance equation: skeletal muscle mass in kg = [0.401 × (height in cm²/resistance in Ω) + (3.825 × gender, for men the gender value is 1 and for women it is 0) − (0.071 × age in years) + 5.102] according to a Janssen et al. (2000) article referenced. Segmental body bio-impedance was measured in the individuals using a multiple frequency Maltron system. Electrodes were attached to the proximal and distal points of both upper and lower extremities separately of the arm, leg, and torso to measure the segmental impedance of each. Individuals were tested on a non-conducive surface in a supine (laying down face up) position with their upper extremities abducted from their trunk and lower extremities slightly apart. Body composition analyses were done via associated bio-impedance software. Shoulder strength was measured by a shoulder Nottingham Mecmesin Myometer (measures isometric muscle strength) at the five shoulder planes previously mentioned (forward flexion, abduction in scapular plane, abduction in

Though perhaps expected, on average the men were taller (women at 1.65 ± 0.06 meters, men at 1.77 ± 0.05 meters) and heavier than the women ( women at 62.6 ± 9.7 kg, men at 81.1 ± 13.7) , resulting in a higher body mass index measurement (women at 23 ± 3.6 kg/m², men at 25.9 ± 4.3kg/m²). The results of the bio-impedance measurements indicated skeletal muscle mass (arm: 3.5 ± 0.6 kg for men, 2.2 ± 0.3kg for women) , skeletal muscle index (arm: 1.1 ± 0.2 for men kg/m², ,0.8 ± 0.1 for women kg/m²,), and fat free mass measurement (body: 60.5 ± 7.3 kg for men, 44.2 ± 3.8kg for women) varied greatly between men and women with men having greater values. However, there was little to no difference between genders in terms of body fat measurements (body: for men 20.7 ± 8.9kg, 18.4 ± 7.0kg for women) . The Nottingham Mecmesin Myometer results showed significant differences in all of the strength measurements that were found between the genders except those of abduction in the scapular plane (arm skeletal muscle mass: 28.8 ± 6.6 for men, 27.9 ± 5.1 for women)and abduction in the coronal plane (arm skeletal muscle mass: 27.9 ± 5.1 for men, 27.7 ± 4.9 for women. When these overall values for isometric