Comparative biomechanics and pathology of mammalian feet
Lead Research Organisation:
Royal Veterinary College
Department Name: Comparative Biomedical Sciences CBS
Abstract
Foot disorders such as arthritis, tendonitis, osteomyelitis and injuries including bone fractures are the major musculoskeletal health problem for most captive/domestic animals, with huge global economic costs due to disabled and euthanised animals. The mechanical interaction between the foot and the ground is a critical contributor. It also influences obesity, weakness, and exercise, which worsen mechanical conditions. In particular, high-frequency vibrations when the foot impacts the ground during locomotion, as well as large forces (hence stresses, or pressures) imposed later in the step, are major causes or influences. However, foot anatomy varies enormously. Horses have an extreme design with one toe ending in a rigid hoof, which is superb for fast-swinging but very stiff. When this rigid hoof hits the ground, it generates large vibrations, and these vibrations can cause gradual accumulation of tissue damage. The foot is so small relative to the body that internal stresses may be highly concentrated. In contrast, elephants represent another extreme: their feet have five toes bound in a flexible pad of fatty, fibrous tissue (the digital cushion), which is heavy and thus costly to swing, but seems strong and seems to dampen vibrations at 'heel' impact. Other large mammals have similar anatomies. Is this foot design thus a marvellous solution that controls high-frequency impacts and stresses in giant animals? How then do intermediate designs such as pig 'trotters' work? Such important questions surprisingly remain almost ignored. We propose to study 5 species (pigs, horses, cows, rhinos, elephants) from 80-3000 kg mass, to measure how foot anatomy and body size influence foot loading. We will do this with a 3-part analysis of locomotion and its links with foot disease. First, we will use motion capture cameras and force platforms to measure the dynamics of the limbs and feet during walking and slow running (e.g. trotting). This will enable us to characterize the mechanics of foot impact with the ground. By characterising how impacts change across a ~100x size range, we will quantify how feet are designed to control impacts. We hypothesise that impact levels are maintained at near-constant levels across animal sizes by foot specialisations. This may inspire new designs for foot prosthetics or cushioned surfaces for animal enclosures. Second, we will 'zoom in' on the mechanics of the feet alone, using 3D high-speed motion capture and regional pressure measurements to determine how the external foot deforms during locomotion and how those deformations relate to localised pressures. Next, we will replicate this mechanical environment using in vitro loading of cadaveric feet and 3D fluoroscopic video to measure how the internal foot deforms. Finally, we will use CT and MRI scans to build highly realistic Finite Element models of these feet and the mechanics we have measured in vivo and in vitro, to estimate the peak stresses in bones and other tissues of the feet during running. We hypothesise that across species, peak bone stresses are kept at near-constant levels to preserve margins of safety that avoid injury. This safety however can easily be lost by damage (e.g. by vibration) or altered mechanics, such as obesity or weakness. Third, we will conduct a broad survey of our study species, and their wild relatives for domestic animals, to quantify which specific regions of the feet tend to develop foot disorders. We hypothesise that animals will have more disease in regions where our models and experiments show the highest stresses during locomotion. This should inspire new diagnostic and preventative measures for foot disorders. Our novel diversity of methods and powerful comparative approach will generate an explosion of research into the mystery of animal foot anatomy and mechanics, and with its strong links to clinical applications will build a new foundation to broadly benefit health and welfare.
Technical Summary
Locomotor loading frequencies and amplitudes have causal links with foot pathologies, e.g. osteoarthritis and bone fracture. What do animals do to keep these mechanics at safe levels? Foot anatomy and dynamics are the first defence. We will use scaling theory to quantify how foot-substrate impact vibrations and midstance stresses change (or remain constant) with animal sizes, locomotor behaviours and anatomies, using 5 species from 80-3000 kg mass. First, we will use forceplates and motion analysis to quantify limb loading in walking and running. This will determine how impact dynamics scale across 2 orders of magnitude. Second, we will combine in vivo, in vitro and in silico analyses of foot function. For the in vivo analysis we will use 3D motion capture (with a mesh of markers on the feet) and pressure plates to quantify 3D deformations of and regional sole pressures on the fore and hind feet. We will then use hydraulic loading frames to axially load cadaveric feet, replicating the mid-stance in vivo loads. We will measure internal 3D foot deformations with 2 high-speed fluoroscopic cameras, and synchronous pressure plate recordings to ensure optimal matching of in vitro and in vivo conditions. Finally, co-registered CT and MRI scans will help construct 3D anatomical models for meshing into Finite Element Analysis (FEA) software, replicating the in vitro analyses. With sensitivity analysis and speckle laser validation, we will conduct the most rigorous estimates of 3D stresses in animal feet yet conducted. This will test how well-engineered larger animal feet are for maintaining (even reducing) bone stresses. Third, our broad survey of animal feet (including wild relatives) using clinical, cadaveric and museum specimens will quantify which regions experience the most common pathologies. Regions experiencing the highest stresses should have the highest incidence of pathologies, forming a new predictive clinical foundation for foot diseases in large mammal
Publications
Akrami M
(2018)
Subject-specific finite element modelling of the human foot complex during walking: sensitivity analysis of material properties, boundary and loading conditions.
in Biomechanics and modeling in mechanobiology
Clark CJ
(2023)
The Inverse Krogh Principle: All Organisms Are Worthy of Study.
in Physiological and biochemical zoology : PBZ
Dudley RJ
(2015)
Radiographic protocol and normal anatomy of the hind feet in the white rhinoceros (Ceratotherium simum).
in Veterinary radiology & ultrasound : the official journal of the American College of Veterinary Radiology and the International Veterinary Radiology Association
Fujiwara S
(2011)
Topsy-turvy locomotion: biomechanical specializations of the elbow in suspended quadrupeds reflect inverted gravitational constraints.
in Journal of anatomy
Hutchinson JR
(2011)
From flat foot to fat foot: structure, ontogeny, function, and evolution of elephant "sixth toes".
in Science (New York, N.Y.)
Hutchinson JR
(2021)
The evolutionary biomechanics of locomotor function in giant land animals.
in The Journal of experimental biology
Panagiotopoulou O
(2016)
A preliminary case study of the effect of shoe-wearing on the biomechanics of a horse's foot.
in PeerJ
Panagiotopoulou O
(2012)
Statistical parametric mapping of the regional distribution and ontogenetic scaling of foot pressures during walking in Asian elephants (Elephas maximus).
in The Journal of experimental biology
Panagiotopoulou O
(2019)
Foot pressure distribution in White Rhinoceroses (Ceratotherium simum) during walking.
in PeerJ
Description | While we are still completing some final analyses and publications from this study, we have confidently established the following: 1) There are significant differences between wild and captive species' foot pathologies in terms of incidence, severity and type of disease. Osteoarthritis is most common, but other details vary markedly among species and between wild vs. captive-raised animals. 2) The above findings support the theory that there is a link between foot mechanics and pathology, which can cause normally high stresses in particular regions of the feet (such as the third to fifth toes/nails in elephants) to be exacerbated to levels that induce or promote degenerate joint disease or other pathologies. 3) We also found major differences in how smaller and larger animals' feet impact the ground during walking and running and between how the fore and hind feet of animals are loaded. At impact ("heelstrike"), forefeet tend to be loaded to greater levels and at higher rates than in hindfeet; a disparity that is maintained as animals evolve to larger sizes. This was the first comparative analysis of how animal feet strike the ground, and is relevant to understanding the impact vibrations that are suspected to cause fatigue damage to tissues and potentially lead to foot diseases. 4) We serendipitously discovered that elephants have false "sixth toes" that are sesamoid (tendon-anchoring) bones near the toes that have been changed during elephant evolution to act less as tendon attachments and more as somewhat independent toe- or lever-like structures. These odd organs have been enlarged into a giant, elongate structure that extends back into the fatty heel pad in elephant fore and hind feet, and helps to support that pad during standing and moving. They seem to develop by a unique process of late conversion of a large cartilaginous rod into patchily organized bone. We found fossil evidence for how this structure evolved as elephants became more terrestrial, larger, and less flatfooted, developing both the foot pad and "sixth toes" to help support their feet and spread out loads. 5) We have also created new ways to measure animal locomotion and mechanics that could reduce, refine and replace invasive methods as well as improve general welfare by predicting the outcomes of clinical interventions. For the first time, we have combined three-dimensional x-ray images of animal foot motion with foot pressures and forces to analyze these experimental data in anatomically realistic, 3D musculoskeletal and finite element computer models. This workflow enables us to predict or estimate the tissue stresses in any region of the feet of an animal given knowledge of how the foot moves and is loaded, and its anatomy. This is giving us new insight into why foot diseases can be induced by suboptimal husbandry conditions in captivity, as well as the consequences of differences in foot form and locomotor behaviour that have evolved in animals. |
Exploitation Route | Further research into mechanics-pathology linkage during completion and elaboration of project. Communication with zookeepers (ongoing) and policy makers (connection needs to be made). |
Sectors | Agriculture, Food and Drink,Environment,Healthcare,Culture, Heritage, Museums and Collections,Pharmaceuticals and Medical Biotechnology,Other |
URL | http://whatsinjohnsfreezer.com/2015/09/23/elephant-feet-2/ |
Description | Refinement of management techniques for care of foot health in captive animals-- e.g. gait analysis for hoofed mammals, documentation of/radiographic techniques for detecting foot pathologies (elephants, rhinoceroses, etc). New applications of statistical parametric mapping to foot pressure data in mammals. Novel integration of 3D-fluoroscopic analysis of skeletal motion with musculoskeletal modelling and finite element analysis for non-invasive study of musculoskeletal tissue mechanics. |
Sector | Agriculture, Food and Drink,Digital/Communication/Information Technologies (including Software),Healthcare,Culture, Heritage, Museums and Collections,Other |
Impact Types | Policy & public services |
Description | EU Marie Curie FP7 Reintegration Grant (Coordinator), |
Amount | £24,577 (GBP) |
Organisation | European Commission |
Sector | Public |
Country | European Union (EU) |
Start | 12/2010 |
End | 12/2012 |
Description | Sesamoid bones: an evolutionary, modelling and experimental perspective |
Amount | £53,500 (GBP) |
Organisation | The Royal Society |
Department | Royal Society Leverhulme Trust Senior Research Fellowship |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 09/2012 |
End | 09/2013 |
Description | The evolutionary biomechanics of sesamoid bones in the limbs of vertebrates: a synthesis |
Amount | £284,288 (GBP) |
Organisation | The Leverhulme Trust |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 08/2013 |
End | 08/2016 |
Description | Towards the chicken of the future: compromises and constraints in the locomotion and breathing of broiler chickens |
Amount | £407,879 (GBP) |
Funding ID | BB/I021116/1 |
Organisation | Biotechnology and Biological Sciences Research Council (BBSRC) |
Sector | Public |
Country | United Kingdom |
Start | 12/2011 |
End | 12/2014 |
Description | New collaboration with Brown University |
Organisation | Brown University |
Country | United States |
Sector | Academic/University |
PI Contribution | New collaboration with fellow (now at RVC ) on dinosaur foot pressures/mechanics, as per EU Marie Curie fellowship. |
Start Year | 2011 |
Description | New collaboration with MIT researchers |
Organisation | Massachusetts Institute of Technology |
Country | United States |
Sector | Academic/University |
PI Contribution | Sharing MRI and CT scan data of elephant feet, and expertise on this subject. |
Collaborator Contribution | Using scan data to construct computer models to test how anatomical structures function, and interpret this vs. e.g. their data for human feet/biomedical applications. |
Impact | Collaboration applying biomechatronic/prosthetic research and engineering techniques to studying elephant feet, integrating these data with anatomical and biomechanical data from our BBSRC-funded elephant/mammal foot biomechanics study. Scientific outreach and public engagement activities such as promoting the research collaboration via Twitter. |
Start Year | 2015 |
Description | New collaboration with Todd Pataky (Shinshu University, Japan) |
Organisation | Shinshu University |
Country | Japan |
Sector | Academic/University |
PI Contribution | New collaboration with Shinshu Univ., Japan on elephant/other animal foot pressure patterns, including J Exp Biology paper in press; ongoing. |
Start Year | 2011 |
Description | New collaborations with Andrew Pitsillides (RVC) - and Alan Boyde (QMUL) |
Organisation | Royal Veterinary College (RVC) |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | New collaborations with RVC and Queen Mary Univ. London on 2011 Science paper, to conduct elephant foot bone imaging and histology; ongoing. |
Start Year | 2011 |
Title | Consultations on care/health of captive elephants |
Description | Since 2005, Hutchinson has been working with a number of zoos and safari parks in order to improve management of elephants in captivity. |
Type | Management of Diseases and Conditions |
Current Stage Of Development | Refinement. Clinical |
Year Development Stage Completed | 2012 |
Development Status | Under active development/distribution |
Impact | The Curator of Colchester Zoo commented: "RVC's research into the locomotion of large animals has underpinned our studies Intractable problems of foot health have been one of the most common causes of death and euthanasia for elephants in captivity. Over 70 elephants are kept in the UK and Ireland, and Defra has commissioned research into the welfare, housing and husbandry of the UK population. If zoos and safari parks do not improve their conditions for elephants, they risk losing them altogether... Our collaboration has led to ways of monitoring gait for abnormalities that may indicate discomfort from infection, disease or damage at the earliest stage and so assist in addressing these problems promptly These methods of gait analysis and foot inspection are now becoming standardised and are being disseminated as best practice across the zoological community internationally." Similar impact was noted in 2013 by Nic Masters of the Zoological Society of London. |
Description | BBC TV appearance |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Media (as a channel to the public) |
Results and Impact | PI Hutchinson was a featured consultant on this BBC TV documentary, shown studying how elephants move (BBSRC funded research work) and how this relates to interpreting fossil organisms (NERC funded research work). The programme was a massive success internationally (reportedly breaking BBC documentary records), with millions of viewers (8.5M in the UK on the first night alone) and ongoing discussions as well as likely lead-ins to future documentary programme involvement by Hutchinson's team. |
Year(s) Of Engagement Activity | 2016 |
URL | http://www.bbc.co.uk/programmes/p03dwy5z |
Description | Cambridge University Biological Society lecture |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Undergraduate students |
Results and Impact | Public seminar entitled "The evolutionary struggles of giant land animals against gravity" to local zoological society, which stimulated discussion of my team's BBSRC- and NERC-funded research projects afterwards, and subsequent emails thanking me for my stimulating presentation as well as an invitation to do future events. |
Year(s) Of Engagement Activity | 2015 |
Description | Charles Darwin BSF award lecture |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | Yes |
Geographic Reach | National |
Primary Audience | Public/other audiences |
Results and Impact | The lecture theatre was fully booked (250 attendees) for the highly interactive presentation (incorporating the Be The Dinosaur simulation), with many visitors staying on to ask questions and examine specimens, plus subsequent discussion via Twitter. All feedback responses rated the event 'good' or 'excellent, with a good level of understanding regarding overall research results |
Year(s) Of Engagement Activity | 2012 |
URL | http://www.britishscienceassociation.org/sites/default/files/root/festival/BSFprog12%20lr%202.pdf |
Description | Discovery Channel of Canada |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Media (as a channel to the public) |
Results and Impact | Discovery Channel of Canada, Daily Planet (TV feature on our pig foot mechanics research; ongoing): Discovery Channel of Canada, Daily Planet (TV feature on our pig foot mechanics research; ongoing): no actual impacts realised to date |
Year(s) Of Engagement Activity | 2011 |
Description | Inside Nature's Giants Documentary |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | The "Inside Nature's Giants" documentary series, first screened on Channel 4 in 2009, had 1.2-2 million viewers per episode in the UK, and won the 2010 BAFTA award in the Specialist Factual category. The National Geographic channel also bought the series, increasing the potential reach to 160 million homes in 143 countries. Prof. Hutchinson was a consultant for the programme, editing scripts and providing 60 hours of paid scientific/technical expertise as well as appearing onscreen in 2 episodes and giving acknowledged input on the website content. BBSRC-funded elephant research was featured in 1 episode, and NERC-funded crocodile research in another (Nat. Geo.); both by Prof. Hutchinson. His invitation to act as a consultant on this production was a direct result of the scientific publications on elephant locomotion and his personal interactions with zoos and elephant keepers during the research. Three further series have followed, with episodes broadcast on PBS in the USA in 2012. Since 2011, a book, DVDs and iPad App have been sold based on the programmes. Very broad viewership, awards and general acclaim. Led to many future media requests with Prof. Hutchinson (more documentaries) and interest in his science communication blog http://whatsinjohnsfreezer.com/. |
Year(s) Of Engagement Activity | 2009,2010 |
Description | Media report on new publication (horse locomotion/foot-shoe interactions) |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Patients, carers and/or patient groups |
Results and Impact | Report by prominent horse enthusiast media on our 2016 publication in PeerJ about horse foot biomechanics. Led to social media interactions with public, discussing issues raised by the basic science. |
Year(s) Of Engagement Activity | 2016 |
URL | http://www.horsetalk.co.nz/2017/01/21/steel-horseshoes-mechanical-loading-foot/#axzz4WQR71WDj |
Description | NatGeo TV appearance: giant rhinoceroses |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Media (as a channel to the public) |
Results and Impact | Featured appearance in "Top 10 Biggest Beasts Ever" documentary on NatGeo TV, focusing on interpreting the anatomy and behaviour of giant extinct rhinoceroses (relevant to NERC and BBSRC grant research). |
Year(s) Of Engagement Activity | 2015 |
URL | http://natgeotv.com/uk/top-10-biggest-beasts-ever |
Description | News coverage of horse foot research |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Public/other audiences |
Results and Impact | New Zealand media story on PeerJ paper published from this grant's research (on potential effects of horseshoes on foot mechanics, indicating higher regional loads on the hoof/foot bones caused by shoeing). |
Year(s) Of Engagement Activity | 2017 |
URL | https://www.horsetalk.co.nz/2017/01/21/steel-horseshoes-mechanical-loading-foot/#axzz4WQR71WDj |
Description | News feature (Daily Mail) |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Media (as a channel to the public) |
Results and Impact | News story about collaborative work following on from our BBSRC grant, focusing on the foot pressures that elephants experience while walking and how studying this helps us monitor and improve the health of captive elephants. Directly related to our BBSRC foot biomechanics grant research and the techniques we pioneered there. |
Year(s) Of Engagement Activity | 2015 |
URL | http://www.dailymail.co.uk/sciencetech/article-2998797/The-perfect-pedicure-ELEPHANTS-Technique-meas... |
Description | News feature (Daily Planet) |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | Very popular science/nature news programme did ~5 minute interview with PI John Hutchinson about the anatomy of elephant feet and his team's research on them, and how this work helps captive or other animals, e.g. with foot problems. Prof. Hutchinson also did a blog post on his "What's In John's Freezer?" blog related to this story, and that had >1000 readers since posting in late 2015. http://whatsinjohnsfreezer.com/2015/09/23/elephant-feet-2/ |
Year(s) Of Engagement Activity | 2015 |
URL | http://review.bellmedia.ca/view/1057528094 |
Description | News features on our elephant foot evolution study (Science 2011) |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | international |
Primary Audience | Media (as a channel to the public) |
Results and Impact | Over 60 TV, radio, print and web features worldwide on this work. Broadcast material no actual impacts realised to date |
Year(s) Of Engagement Activity | 2011 |
Description | News features on our rhinoceros foot pressure studies (ongoing): |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Participants in your research or patient groups |
Results and Impact | BBC (BBC Breakfast, BBC News Online, BBC Radio Scotland): ITV (TV, website): http://www.itv.com/anglia/rhino-research48459 Daily Mail: http://www.dailymail.co.uk/sciencetech/article-2086135/Rhinos-feet-studied-help-relieve-pain-zoo-animals.html Also featured article in International Zoo News Vol. 59, No. 1 (2012), pp. 34-39. Further featured in: Daily Planet (Discovery Channel Canada), ITV Anglia Tonight, Colchester Gazette, MSNBC, TruthDiver. News features on our rhinoceros foot pressure studies (ongoing): no actual impacts realised to date |
Year(s) Of Engagement Activity | 2010 |
URL | http://www.itv.com/anglia/rhino-research48459 |
Description | Royal College of Veterinary Surgeons, Share Jones Lecture in Veterinary Anatomy |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | Yes |
Geographic Reach | Local |
Primary Audience | Professional Practitioners |
Results and Impact | An audience of about 100 listened to the latest research results from Dr. Hutchinson's team, which stimulated questions and discussion afterwards. Further invitations for speaking engagements by Prof. Hutchinson have stemmed from this. |
Year(s) Of Engagement Activity | 2011 |
URL | http://www.rcvs.org.uk/news-and-events/news/share-jones-lecture-2011-big-and-nimble/ |
Description | Science Blog |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | Anatomy blog: sharing the latest scientific research and insights from Prof. Hutchinson's team, with a strong focus on RCUK-funded research. Highly visual and stimulating discussion. As of submission in 2016, total 354,000 views, 3239 followers, 1855 comments, 161 posts. 255,944 all-time views (average 250/day) as of 14/10/2014; 1,529 comments, 750 Subscribers, 642 shares; with additional viewers (53,412) and subscribers (92) at associated Youtube Channel: https://www.youtube.com/user/Whatsinjohnsfreezer |
Year(s) Of Engagement Activity | 2012,2013,2014,2015,2016 |
URL | http://whatsinjohnsfreezer.com/ |
Description | Twitter: Science Communication |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | Persistent, daily public engagement by Prof. Hutchinson on his personal account, which regularly addresses scientific research that his team is conducting, including RCUK-funded research. Averages ~250,000 impressions/month; as of submission in 2016 is 27,500 tweets total, 4778 followers, 1652 photos and videos. >19,000 tweets, >3,000 followers, Klout score ~63 as of 14 October 2014-- indicates strong engagement in science communication. Twitter Analytics indicate 224.9K impressions (views) and thousands of engagements (clicks, favourites, retweets, replies etc.) during a representative month. |
Year(s) Of Engagement Activity | 2012,2013,2014,2015,2016 |
URL | https://twitter.com/JohnRHutchinson |