What is biomechanics?
Biomechanics refers to the study of the mechanical principles of living organisms, particularly their movement and structure. It is prominent in the developing world as it allows for better scientific understanding of the natural aspects around us and hence enables us to incorporate evolving technology for improvement in the way we live. In medicine, a prosthesis is an artificial device that replaces a missing body part, which may be lost through trauma, disease, or congenital conditions. Prosthetics are intended to restore the normal functions of the missing body part. These are currently being made using Robotics (the branch of technology that deals with the design, construction, operation, and application of robots). I will specifically discuss prosthetics in biomechanics as their incredible ability to imitate such complicated actions and progress on the way we live seems vital to adapting to the modern age of technological advances. To evolve, however, we must acknowledge the history.
The Development of Biomechanics and Prosthetics
Aristotle can be considered the first bio-mechanic, because of his work with animal anatomy. Aristotle wrote the first book on the motion of animals, De Motu Animalium, (the Movement of Animals). Prosthetics have been mentioned throughout history. The earliest recorded mention is the warrior queen Vishpala in the Rigveda. However, developing mobile prosthetics was not developed until the 20th century when an Italian surgeon recorded the existence of an amputee who had an arm that allowed him to remove his hat, open his purse, and sign his name. Improvement in amputation surgery and prosthetic design came at the hands of Ambroise Paré. Among his inventions was an above-knee device that was a kneeling peg leg and foot prosthesis with a fixed position, adjustable harness, and knee lock control. The functionality of his advancements showed how future prosthetics could develop.
What is the aim
Physical disabilities can be sensory, where there are problems with sight, hearing or speech, or they may impair motor function, so that movement is restricted or imprecise. Injuries may cause a disability, and disease such as a heart condition may also make normal exertion impossible. Some disabilities start at birth – congenital disabilities. Others are acquired during life. In any case, science wants to help. For amputees, prosthetics progression provides a future.
Modern prosthetic hands look human, but their movements are limited and robotic. Researchers are striving to transform prosthetics by recreating the natural brain-to-hand control signals. Current prosthetic hands have the same number of joints as human hands and could theoretically perform complex movements. However, this may not be possible until we understand the complete set of signals that a human hand normally receives
The current goal is to help a patient perform ordinary, day-to-day activities. At the minimum, a prosthetic should help an amputee take care of basic tasks such as eating, walking, and getting dressed. Technology in prosthetics has improved to the point where some amputees can do everything they did before they lost their limb. Some people with prosthetics have even done amazing things such as climbing mountains or running marathons.
Scientist researchers are currently using some simple applications of Newtonian mechanics and materials sciences to supply correct approximations to the mechanics of many biological systems. Mechanical engineering disciplines such as structural analysis, kinematics and dynamics all play prominent roles in the study of biomechanics. Usually biological systems are much more complex than man-built systems. Hence, Numerical methods are applied in almost every biomechanical study. Research is done in an iterative process of hypothesis and verification, including several steps of modelling, computer simulation and experimental measurements. Some simple examples of biomechanics research include the investigation of the forces that act on limbs, the aerodynamics of bird and insect flight, and the hydrodynamics of swimming in fish.
What we already know is that when electrical signals from the brain reach a muscle, it does not generate force instantly. The action potentials through the muscle, changing ion concentrations and forming bridges between certain proteins that then result in muscle contraction, so it takes time for the neural command that reaches a muscle to be translated into muscle activation. This process is called Activation Dynamics. Researchers collect this data and use it to imitate real life biomechanics in real time.
Implications- risks and ethical
Implications- as a human
Tony was born without his left arm below the elbow so visited Keele University to discuss his thoughts on the current upper limb prosthetic options and his views on his own prosthesis use. He is retired and enjoys an active lifestyle which includes frequent visits to the gym and driving a manual car, for both of which he relies heavily on his prosthesis. To people like Tony, Aesthetics matter. Prosthesis needs to be both functional and as unnoticeable as possible. Access to several different attachments, such as a hook (useful for the gym) and a typing tool make the prosthesis useful for a variety of everyday tasks. However the attachments are not helpful during certain activities, such as swimming so scientists are looking into a change in the design and weight of the prosthesis that would be beneficial in making this activity easier.
“My whole life has been adapting. I look at a problem and say “how can I do this”, not “I can’t do it”. I look at it and say, “I know I can do this” and I find a way.”
This is just one example of the benefits of this research, its vitality and potential for improvement in the foreseeable future.
Researchers at Keele and Newcastle Universities are developing ways to convert the user’s desired action into movement of the prosthetic hand, and to generate sensory feedback from the prosthesis to the brain. One way to do this is using machine learning to combine muscle and motion signals from the residual limb. Another way is to feed electrical signals from residual muscles through a computer model to interpret the desired action. Their goal is that one day, prosthetic hands will move and feel like the real thing.