They've come up with a set of equations to identify the physical laws of nail growth, and used them to throw light on the causes of some of the most common nail problems, such as ingrown toenails, spoon-shaped nails, and pincer nails.
"It is remarkable what some people are willing to do to make their nails look good," says study researcher Cyril Rauch.
According to the research, published in the journal Physical Biology, regular poor trimming can tip the fine balance of nail growth, causing physical stress to the nail. Over time, this can cause a change in nail shape, which can lead to serious nail conditions.
"Looking at our results, we suggest that nail beauty fanatics who trim their nails on a daily basis opt for straight or parabolic (curved in an arch) edges, as otherwise they may amplify the imbalance of stresses, which could lead to a number of serious conditions," Rauch says.
In other words, choose a simple shape to minimize stress on nail growth.
Nail Growth Equations
The researchers came up with an overall nail shape equation after taking into account the forces that allow the nail to slide forward and grow.
The equation showed that when the forces are off-balance, or if a nail grows too quickly or slowly, stress across the entire nail could happen, causing it to change shape over time.
The equation showed the stress is greater for nails that are large and have a flatter edge, which could explain why ingrown toenails mostly happen to the big toe.
The researchers also suggest that ingrown, pincer, and spoon-shaped nails are related conditions.
They say nail trimming is important and should be carefully done, especially with the increasing number of nail salons.