What's the buzz

What's the buzz

Hips power our walk, while ankles our run

Researchers at North Carolina State University have compared the role of hips, knees and ankles for walking and running motions.

They found that hips generate more of the power when people walk, but the ankles generate more of the power when humans run. Knees provide approximately one-fifth or less of walking or running power, according to the study.

The finding could help inform the best ways of building assistive or prosthetic devices for humans, or constructing next-generation robotics. The study showed that hips generate 44 per cent of the power when people walk at a rate of 2 metres per second, with ankles contributing 39 per cent of the power.

When people start running at this 2-meter-per-second rate, the ankles really kick in, providing 47 per cent of the power compared to 32 per cent for the hips.

Ankles continue to provide the most power of the three lower limb joints as running speeds increase, although the hips begin closing the distance at faster speeds.

Increase in calcium intake will not reduce fracture risk
Increasing the daily intake of calcium from 700 mg a day will not reduce the risk of fractures or Osteoporosis in later life.

With growing age, the risk of fractures and Osteoporosis also grows, as bones start losing calcium — this is especially the case for women. Whether increase in calcium intake can compensate for the loss of calcium has been debated for a long time but there is still no clear advice.

In order to establish a link between calcium intake and the risk of fractures, authors, led by Dr Eva Warensjo from Uppsala University in Sweden, reviewed data from a large population study of Swedish women that was carried out in 1987.

All participants were followed up for 19 years. During the follow-up 24 per cent women had a first fracture and, of these, 6 per cent had a first hip fracture. 20 per cent of the sub-group had osteoporosis.

The researchers used a series of questionnaires to investigate the participants’ changing diet and in particular their calcium intake and use of supplements and multivitamins.

Damaged liver could be repaired using stem cells
Researchers have found a way to repair damaged livers using adult stem cells.
The finding by Johns Hopkins researchers could one day be used as an alternative to liver transplant in patients with serious liver diseases, bypassing long waiting lists for organs and concerns about immune system rejection of the donated tissue.

They have demonstrated that human liver cells taken from adult stem cells — known as induced-pluripotent stem cells (iPSC) — coaxed into an embryonic state can engraft and begin regenerating liver tissue in mice with chronic liver damage.

iPSCs are made from adult cells that have been genetically reprogrammed to revert to an embryonic stem cell-like state, with the ability to transform into different cell types.