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 has good elasticity. If it returns only 50% or less, it is structurally weak and may require protein treatments.
Is the hair damaged?
Damaged hair is often the result of excessive environmental, chemical, thermal or mechanical styling stress. It may be weak and brittle when dry, spongy or stretchy when wet. Damage may be externally or physically obvious, or internal.
To determine if the cuticle is damaged, perform this simple test; separate a 1 to 2 inch section of hair and hold it firmly between your thumb and fingers. Slide the thumb and forefinger of your other hand along this section from the ends toward the scalp. If the hair seems to easily tease or “back-comb” between your fingers, the cuticle is damaged (note; this test is not effective with curly hair types). Usually, damaged hair requires moisture and protein treatments to reinforce and help return it to a healthy state.
Hair that can absorb and retain moisture has good or acceptable porosity. Varying degrees of porosity result when:
Over-porous hair can be caused by excessive heat styling, bleaching, coloring, or other chemicals such as TR, BKT, relaxers and permanent waves. It may feel slimy when wet and brittle when dry.
Porosity needs to be considered when selecting TR and hair coloring products – it determined formula mixtures and processing times. When the hair is weakened or in poor condition, it is advisable to treat it and ensure the best possible TR, BKT and hair color results.
The structure of the damaged hair is considered ‘disordered”. Internally, the fibrils of the cortex may be separated in spots causing hair to be weak and over-porous.
Damage to the cortex can be caused in a number of ways. Styling tools such as a dryer used too close to the hair, or a hot iron left on too long can actually melt the cortex. Improper use of perms, TR, BKT, relaxers, lighteners, tints and over-exposure to the sun can also damage the cortex. The result: weakened, dry, brittle and dull-looking hair.
Usually if the cortex is damaged, the cuticle has been damaged too.
A damaged or “abraded” cuticle is often the result of mechanical friction to the fiber. Wet-brushing and combing, towel-drying, repeated use of thermal styling equipment, improper cutting techniques, teasing, braiding, use of rubber bands and tight clips all cause breakage of the cuticle scales.