An elasticity test assesses hair tensile strength. Remove a strand of hair from the side of the head above the ears. Hold it between your thumb and forefinger. With the thumbnail and index of nail of the other hand, run the distance of the hair rapidly, as you would curl a ribbon with scissors. This should create a series of small curls. Then, gently pull the hair straight for 10 seconds and release.
If the hair completely or almost completely returns to the curl pattern, it is in good condition. If it returns only 50% or less, the hair is structurally weak and will require reconditioning - Under NO circumstances should any major salon services (permanent wave, color or BKT/TR) be given when the hair is in this range. It needs proper hair care and a network of protein to build strength and flexibility into hair to give it substance and resilience.
Understanding the structure and composition of hair contributes to an overall appreciation of reconditioning. Hair is a fibrous structure that consists of:
The Cortex, a spiral of proteins that forms the inner structure of hair.
The Cuticle, flat, hardened keratin protein that surrounds the cortex.
Besides protein, water makes up most of the rest of hair’s composition. A balance between protein and moisture is essential to healthy hair. When that balance is damaged by external elements, heat styling or excessive chemical services, hair needs reconditioning.