One small step for man...Research reveals what makes human feet unique

Scientists have made a step forward in understanding the evolution of human feet.

Unlike species such as chimpanzees, which have opposable digits on their feet, humans have evolved arched feet to enhance upright walking.

These arches were thought to be supported by plantar intrinsic muscles (PIMs) -- but a study by the University of Queensland and the University of Exeter shows PIMs have a "minimal impact" on this.

The findings show that foot muscles are important for helping us push against the ground during walking and running. This suggests that strong foot muscles could be key to our ability to walk and run.

"Recent research suggests that muscles in our feet are key to how the foot functions during walking and running," said lead author Dr Dominic Farris, of the University of Exeter.

"Our study provides direct evidence showing the significance of these foot muscles in supporting the performance of the human foot.

"Contrary to expectations, PIMs contribute minimally to supporting the arch of the foot during walking and running.

"However, these muscles do influence our ability to produce forward propulsion from one stride into the next."

To test PIMs, the researchers compared foot and lower limb movement with and without a nerve block that prevented contraction of these muscles.

During ground contact in walking and running, the stiffness of the foot arch was not altered by the block, showing that the PIMs' contribution to arch support is minimal, probably due to their small size.

However, with the PIMs blocked, the distal joints of the foot could not be stiffened sufficiently to provide normal push off against the ground.

"This could have implications for understanding conditions such as flat feet, the value of training foot muscles and ideas around potential benefits of running barefoot," said Dr Farris.

"It turns out these muscles aren't important for supporting the arch of the foot, but they are important for propelling us forwards when we walk or run."

The paper, published in the journal Proceedings of the National Academy of Sciences, is entitled: "The functional importance of human foot muscles for bipedal locomotion."

The University of Exeter and The University of Queensland have partnered to establish the QUEX Institute, a new multi-million pound partnership designed to bolster their joint global research impact.

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Story Source:

Materials provided by University of Exeter. Note: Content may be edited for style and length.

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Journal Reference:

1. Dominic James Farris, Luke A. Kelly, Andrew G. Cresswell, and Glen A. Lichtwark. The functional importance of human foot muscles for bipedal locomotion. PNAS, 2019 DOI: 10.1073/pnas.1812820116

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University of Exeter. "Step forward in understanding human feet." ScienceDaily. ScienceDaily, 14 January 2019. .

Use it or Loose it: Leg exercise is critical to brain and nervous system health

Groundbreaking research shows that neurological health depends as much on signals sent by the body's large, leg muscles to the brain as it does on directives from the brain to the muscles. Published today in Frontiers in Neuroscience, the study fundamentally alters brain and nervous system medicine -- giving doctors new clues as to why patients with motor neuron disease, multiple sclerosis, spinal muscular atrophy and other neurological diseases often rapidly decline when their movement becomes limited.

"Our study supports the notion that people who are unable to do load-bearing exercises -- such as patients who are bed-ridden, or even astronauts on extended travel -- not only lose muscle mass, but their body chemistry is altered at the cellular level and even their nervous system is adversely impacted," says Dr. Raffaella Adami from the Università degli Studi di Milano, Italy.

The study involved restricting mice from using their hind legs, but not their front legs, over a period of 28 days. The mice continued to eat and groom normally and did not exhibit stress. At the end of the trial, the researchers examined an area of the brain called the sub-ventricular zone, which in many mammals has the role of maintaining nerve cell health. It is also the area where neural stem cells produce new neurons.

Limiting physical activity decreased the number of neural stem cells by 70 percent compared to a control group of mice, which were allowed to roam. Furthermore, both neurons and oligodendrocytes -- specialized cells that support and insulate nerve cells -- didn't fully mature when exercise was severely reduced.

The research shows that using the legs, particularly in weight-bearing exercise, sends signals to the brain that are vital for the production of healthy neural cells, essential for the brain and nervous system. Cutting back on exercise makes it difficult for the body to produce new nerve cells -- some of the very building blocks that allow us to handle stress and adapt to challenge in our lives.

"It is no accident that we are meant to be active: to walk, run, crouch to sit, and use our leg muscles to lift things," says Adami. "Neurological health is not a one-way street with the brain telling the muscles 'lift,' 'walk,' and so on."

The researchers gained more insight by analyzing individual cells. They found that restricting exercise lowers the amount of oxygen in the body, which creates an anaerobic environment and alters metabolism. Reducing exercise also seems to impact two genes, one of which, CDK5Rap1, is very important for the health of mitochondria -- the cellular powerhouse that releases energy the body can then use. This represents another feedback loop.

These results shed light on several important health issues, ranging from concerns about cardio-vascular impacts as a result of sedentary lifestyles to insight into devastating diseases, such as spinal muscular atrophy (SMA), multiple sclerosis, and motor neuron disease, among others.

"I have been interested in neurological diseases since 2004," says co-author Dr. Daniele Bottai, also from the Università degli Studi di Milano. "The question I asked myself was: is the outcome of these diseases due exclusively to the lesions that form on the spinal cord in the case of spinal cord injury and genetic mutation in the case of SMA, or is the lower capacity for movement the critical factor that exacerbates the disease?"

This research demonstrates the critical role of movement and has a range of potential implications. For example, missions to send astronauts into space for months or even years should keep in mind that gravity and load-bearing exercise play an important role in maintaining human health, say the researchers.

"One could say our health is grounded on Earth in ways we are just beginning to understand," concludes Bottai.

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Story Source:

Materials provided by Frontiers. Note: Content may be edited for style and length.

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Journal Reference:

1. Raffaella Adami, Jessica Pagano, Michela Colombo, Natalia Platonova, Deborah Recchia, Raffaella Chiaramonte, Roberto Bottinelli, Monica Canepari, Daniele Bottai. Reduction of Movement in Neurological Diseases: Effects on Neural Stem Cells Characteristics. Frontiers in Neuroscience, 2018; 12 DOI: 10.3389/fnins.2018.00336

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Frontiers. "Leg exercise is critical to brain and nervous system health: In a new take on the exercise truism 'use it, or lose it,' researchers show neurological health is an interactive relationship with our muscles and our world." ScienceDaily. ScienceDaily, 23 May 2018. .

Podiatric services can improve chronic care outcomes

By Jessica Kent (healthitanalytics.com)

March 06, 2018 - The integration of podiatric services could enhance chronic care management, improve health outcomes, reduce healthcare costs, and ultimately benefit the shift toward value-based care, according to a study commissioned by the New York State Podiatric Medical Association (NYSPMA).

Researchers conducted a data analysis and literature review of podiatric interventions and their effect on diabetes, obesity, back pain, and fall prevention care.
These conditions have a significant impact on New York residents. NYSPMA noted that approximately two million New Yorkers have diabetes, 25 percent of whom develop foot ulcers.

Twenty-five percent of New York adults and 14 percent of New York children are obese, and 20 percent of the state’s population suffers from back pain.
Researchers found that for diabetic patients with foot ulcers, podiatric services had the potential to reduce approximately 13,500 inpatient admissions annually and could save the healthcare industry nearly $510 million in diabetes costs.

In obese patients, podiatric treatment could reduce subsequent inpatient admissions by approximately 19 percent and save almost $1.1 billion in healthcare costs.

Among patients with back pain and podiatric-related pain diagnosis, researchers found that podiatric services could reduce the odds of opioid dispensation by 28 percent.

Podiatric interventions could also reduce falls for the elderly and at-risk populations by 36 percent.
NYSPMA commissioned the study in response to New York State’s Medicaid reform, which aims to develop projects that will improve health outcomes, decrease costs, and move towards value-based payment models.

As part of their reform, New York is implementing the State Health Innovation Plan, a roadmap that outlines how to boost health outcomes through primary care integration and other initiatives.
The state also plans to implement the New York State Prevention Agenda, which will focus on improving care and increasing preventive services for multiple conditions including diabetes, obesity, substance abuse, and back pain.

NYSPMA stated that podiatric service coverage is currently limited under New York Medicaid, and podiatry is not at the forefront of policy discussions for private payer and provider groups.
However, this study shows that podiatry could be a valuable part of healthcare transformation. It also demonstrates the importance of specialist care in the treatment of chronic conditions and population health management.

Specialty services like podiatry target the holistic treatment of a patient, rather than just treating the symptoms, the NYSPMA stated. The result is better, more comprehensive treatment for patients living with chronic conditions.

“Our findings indicate that expanding podiatry’s role in the New York healthcare landscape may reduce inpatient admissions, lower long-term healthcare costs and decrease opioid dispensing for target populations,” NYSPMA said.

The NYSPMA asserted that it will be vital for podiatrists to develop relationships with payers and other providers as healthcare continues to shift toward value-based care.

“Podiatric intervention is a key component of effectively managing chronic conditions and improving quality of life for New Yorkers,” said Paul J. Liswood, DPM, NYSPMA President-Elect and a Brooklyn-based podiatrist.

“As New York podiatrists, it is our mission to educate New Yorkers about how the expansion of podiatry’s role in the New York healthcare landscape can positively impact the whole person while reducing healthcare costs.”

Diabetic Retinopathy leads to greater fall risk

A Singapore study of more than 9,000 people suggests those with diabetic retinopathy are at increased risk of falls.

People with moderate diabetic retinopathy were nearly twice as likely to fall compared to people with diabetes who did not have any visual problems, while people with mild retinopathy had an 81 per cent increased risk of falling.

The study also found that people with diabetic retinopathy had a 31 per cent greater risk of falling compared to people without diabetes.

While these findings are unnerving, people with diabetes can take steps to reduce their risk of diabetic retinopathy, and control existing retinopathy, through normalising blood glucose levels and blood pressure and receiving eye examinations from an eye specialist every year.

Professor Ecosse Lamoureux, of the Singapore Eye Research Institute and the Duke-NUS Medical School in Singapore, was the lead researcher on the study. Explaining the findings, he said: "Alterations in blood glucose levels in diabetes cause changes in retinal blood vessels which swell, bleed or leak fluid into the back of the eye.

"Diabetic retinopathy causes not only vision loss, but also reduction in the components of the aging visual function system, such as contrast sensitivity, stereo acuity, and colour perception, which can result in poor postural stability and a greater capacity to bump into objects, leading to a greater risk of falling."

The researchers said about one in three older people in the community fall a year but there was limited research on the links between falling and diabetic retinopathy.

The study involved examining the records of 9,481 people living in Singapore who had either Malaysian, Indian or Chinese ethnicity, with about half aged 59 or older. Seventy per cent did not have diabetes.

As the research involved people recalling their memories of falling, this may have resulted in unreliable data.

Commenting on the findings, Dr Francesc Formiga, from Barcelona's Bellvitge Universitari Hospital, said: "Diabetic retinopathy often does not offer any early warnings signs. Therefore, it is important to perform a complete ocular exam at least once a year."

The study was published by JAMA Ophthalmology.

No Bones About It - Your skeleton affects your appetite

Your skeleton is much more than the structure supporting your muscles and other tissues. It produces hormones, too. And Mathieu Ferron knows a lot about it. The researcher at the Montreal Clinical Research Institute (IRCM) and professor at Université de Montréal's Faculty of Medicine has spent the last decade studying a hormone called osteocalcin. Produced by our bones, osteocalcin affects how we metabolize sugar and fat.

In a recent paper in The Journal of Clinical Investigation, Ferron's team unveiled a new piece of the puzzle that explains how osteocalcin works. The discovery may someday open the door to new ways of preventing type 2 diabetes and obesity.

Bone: An endocrine organ
It has long been known that hormones can affect bones. "Just think about how women are more prone to suffer from osteoporosis when they reach menopause because their estrogen levels drop," said Ferron, director of the IRCM's Integrative and Molecular Physiology Research Unit.
But the idea that bone itself can affect other tissues took root only a few years ago with the discovery of osteocalcin. Thanks to this hormone, produced by bone cells, sugar is metabolized more easily.
"One of osteocalcin's functions is to increase insulin production, which in turn reduces blood glucose levels," Ferron explained. "It can also protect us from obesity by increasing energy expenditure."
Studies have shown that, for some people, changes in blood concentrations of osteocalcin may even stave off the development of diabetes. These protective properties sparked Ferron's interest in how this hormone actually works.

Hormone scissors
Osteocalcin is produced by osteoblasts, the same cells responsible for making our bones. The hormone builds up in bone, and then, through a series of chemical reactions, is released into the blood. The IRCM team is focusing on this key step.

"When it is first produced in osteoblasts, osteocalcin is in an inactive form," Ferron noted. "What interested us was understanding how osteocalcin becomes active so as to be able to play its role when released into the blood."

The IRCM lab demonstrated that an enzyme, which acts like molecular scissors, is required. Inactive osteocalcin has one more piece than active osteocalcin. The researchers examined in mice the different enzymes present in cells where osteocalcin was produced that could be responsible for snipping off the piece in question.

Ferron's team succeeded in identifying it: it's called furin. Furin causes osteocalcin to become active and the hormone is then released into the blood.

"We demonstrated that when there was no furin in bone cells, inactive osteocalcin built up and was still released, but this led to an increase in blood glucose levels and a reduction in energy expenditure and insulin production," Ferron said.

Deleting these "scissors" also had an unexpected effect: it reduced the mice's appetite. "We're confident that the absence of furin was the cause," Ferron said.

Indeed, his team demonstrated that osteocalcin itself has no effect on appetite. "Our results suggest the existence of a new bone hormone that controls food intake," Ferron said.

"In future work, we hope to determine whether furin interacts with another protein involved in appetite regulation."

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Story Source:
University of Montreal. "Your bones affect your appetite -- and your metabolism! A Montreal Clinical Research Institute discovery sheds light on this phenomenon." ScienceDaily. ScienceDaily, 1 November 2017.

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Journal Reference:

1. Omar Al Rifai, Jacqueline Chow, Julie Lacombe, Catherine Julien, Denis Faubert, Delia Susan-Resiga, Rachid Essalmani, John W.M. Creemers, Nabil G. Seidah, Mathieu Ferron. Proprotein convertase furin regulates osteocalcin and bone endocrine function. Journal of Clinical Investigation, 2017; 127 (11): 4104 DOI: 10.1172/JCI93437