Pulses of high-frequency sound which can speed up the healing of broken bones and even make them stronger than before could become a useful tool for those in physiotherapy jobs.

Researchers tested the therapy on 100 patients suffering with fractured shin bones or tibia's, that had not healed after more than four months.

Half of the participants were treated using an ultrasound probe and half were treated with a "shame" device. The research took place over a period of 16 weeks and those patients receiving the "real" treatment resulted in faster healing and 34 per cent more bone density at the injury site.

Therapy sessions lasted 20 minutes and were conducted everyday throughout the study period. The treatment, known as low-intensity pulsed ultrasound (LIPUS) is delivered by a small emitter which is linked to a handheld controller. All patients participating in the study were suffering from delayed "union" which is the knitting together of broken bones and it occurs in around 4.4 per cent of tibial fractures.

Sometimes the bones fail to mend at all and currently non-unions are treated with complex and costly procedures which involve the grafting on of extra pieces of bone, aided with growth promoting chemicals. However, ultrasounds have been shown to accelerate fracture healing by boosting the activity of osteoblasts, which are the sells that synthesise bone.

The research was conducted by a team of German scientists and was backed by global medical devices manufacturer Smith and Nephew. Dr Jon Block a US consultant for the company told The Telegraph: "These findings demonstrate significantly greater progress toward bone healing after LIPUS treatment compared to no LIPUS treatment in subjects with established delayed unions of the tibia."

"This should assist in establishing this non-invasive modality as a viable, effective treatment option for patients suffering these injuries," he added.