Washington, Apr 10 (UNI) Backpackers take caution as a recent research has found that backpack straps decrease blood flow in the shoulder, resulting in loss of fine motor control.

The study found that strap pressures with loads as small as ten per cent of bodyweight obstructed localised blood flow and contributed to shoulder fatigue.

Backpack straps rest on an area of the body where they might compress the axillary vein which causes abnormally high blood pressure inside the veins and a subsequent decrease of blood flow in the shoulders and arms.

The researchers speculated that blood flow of the large and small vessels of the upper extremity area would decrease in an individual while wearing a backpack.

It was seen that after wearing the pack for ten minutes, brachial artery blood flow decreased and index finger microvascular flow decreased considerably.

The researchers concluded that backpack loads of just 26 pounds decrease upper extremity macrovascular and microvascular blood flows, and might result in a loss of fine motor control and increased fatigue.

''The mechanism of diminished blood flow is likely due to strap compression of the axillary vein,'' Science Daily quoted Prof Timothy Neuschwander, from the Department of Orthopaedic Surgery, University of California as saying.

''Backpack straps may benefit from a redesign that skirts the vein leading from the upper extremity to the heart,'' Prof Timothy said.

The study said the backpacks were loaded with almost one-fourth of the child's body weight (22 per cent) and worn with only one strap.

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