Want to witness the power behind the next generation of artificial muscles for prosthetics and exoskeletons? Look in your fishing tackle box.
According to a recent announcement from researchers at the University of Texas – Dallas, a process that twists and coils fishing line results in an artificial muscle that can lift more than 100 times the weight of a similar-sized human muscle and can be controlled by relatively simple temperature changes. The research has been reported in Discovermagazine, Health24, and WebMD, among other outlets.
The twisted polymer filament process was developed at the NanoTech Institute at the university. Researchers believe that the technology has immediate applications for exoskeletons but could also be commercialized to create clothing that adapts to changes in temperature. While far less efficient than human muscle, the fibers can generate more than 5 times the energy of an automobile engine.
A study of nearly 36,000 men over a 24-year span has revealed that walking significantly contributes to prevention of hip fractures to an even greater extent than more strenuous activity. Researchers also found that "contrary to expectation," sedentary behavior can serve a preventive role too—particularly when accompanied by 2 or more hours of walking per week.
In the study, e-published ahead of print in the American Journal of Public Health (.pdf), researchers examined data from the Health Professionals Follow-up Study, a project that uses biennial questionnaires to track the health and lifestyle of about 51,000 men. Authors of the hip fracture study focused on reports of 35,996 men aged 50 to 75 from 1986 through 2010.
Over the 24 years of study, 546 hip fractures were reported, and after excluding fractures attributable to malignancy or a major traumatic event such as an automobile accident, researchers were left with 490 cases of fractures, with 85% of those fractures occurring because of a slip, trip, or fall from chair height. Mean age at the time of hip fracture was 77.
In the end, researchers found that after controlling for strenuous activity and all other risk factors, men who reported walking 4 or more hours a week had a 43% lower risk of hip fracture than men who walked for fewer than 4 hours a week. Walking pace also had a dramatic effect: men who spent 4 or more hours walking at a brisk pace experienced a 62% lower risk of fracture.
Authors related the risk reduction associated with walking to improved muscle strength and balance, but they did not see the same relationship when they looked at strenuous activity. Researchers wrote that "in contrast to walking, more time spent in strenuous activity did not reduce risk of hip fracture." In fact, they speculated, the increased risk of falls associated with activities such as running may offset potential risk reduction.
The other major factor in risk reduction is somewhat more problematic. According to the study, "more time spent sitting was associated with a lower risk of hip fracture even after adjustment for total activity and all other risk factors." Researchers wrote that men who sat for 50 or more hours a week reduced their risk of fracture by 38% and could gain a 45% reduction in risk if they also walked for 2 or more hours a week. Authors were careful to note that the analysis was focused on hip fracture only and did not study the effects of sedentary behavior on overall health (see an earlier News Now story on a study highlighting the negative impacts of sedentary behavior).
Authors acknowledged limitations in the study, which focused only on white men who were not institutionalized.
APTA offers its members evidence-based resources on falls through its PT Now webpage as well as through APTA ArticleSearch. In addition, APTA provides physical therapists (PTs) and patients with education on exercise prescriptions for balance and falls prevention, a pocket guide on falls risk reduction (.pdf), an online community where members can share information about falls prevention, and a webpage on balance and falls.
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