Biomechanics is an interdisciplinary field that applies the principles of mechanics to understand the structure, function, and motion of biological systems. It is a vibrant area of research that integrates knowledge from biology, physics, engineering, and mathematics to analyze the forces exerted by and upon living organisms, and the effects produced by these forces. This article delves into the fundamentals of biomechanics, its subfields, and the diverse methods used in biomechanical research.
What is Biomechanics?
“Biomechanics is the study of the structure and function of biological systems by means of the methods of mechanics”
Hatze, H., 1974
From the movement of individual cells to the motion of the entire body, biomechanics seeks to understand how biological systems interact with their environment and how internal and external forces affect these systems. By understanding these interactions, biomechanics contributes to the design of medical devices, improves athletic performance, and enhances our general knowledge of biology.
Subfields of Biomechanics
Biomechanics encompasses a wide range of areas, each focusing on different aspects of the interaction between biological systems and mechanical forces. Here, we explore some of the major subfields:
Sports Biomechanics
Sports biomechanics applies mechanical principles to the analysis of athletic performance. It aims to enhance performance, reduce the risk of injury, and improve training techniques. Researchers in this field might study the optimal technique for a high jump, analyze the forces exerted on a runner’s joints, or develop equipment that enhances athletic ability.
Clinical Biomechanics
This subfield focuses on the application of biomechanics to the diagnosis, treatment, and prevention of medical conditions. It plays a critical role in the design of prosthetics, orthotics, and rehabilitation programs. Clinical biomechanics also includes the study of gait (how people walk) and ergonomics (designing equipment and workplaces to fit the user).
Cellular Biomechanics
Cellular biomechanics investigates the mechanical properties and behavior of cells. This includes studying how cells deform, move, and respond to mechanical stimuli. Understanding cellular biomechanics is crucial for developing new medical treatments and for advancing our knowledge of cell biology.
Comparative Biomechanics
Comparative biomechanics examines the mechanical aspects of different species to understand the diversity of biological strategies for dealing with mechanical challenges. Researchers might study the differences in how various species fly, swim, or move to gain insights into the evolutionary pressures shaping these mechanisms.
Methods of Biomechanical Research
Biomechanical research employs a variety of methods to analyze and interpret the interaction between biological systems and mechanical forces. Here, we explore some of the key techniques:
Motion Analysis
Motion analysis is a pivotal technique in biomechanics, providing insights into the complexities of movement in living organisms. By employing high-speed cameras and motion capture systems, biomechanists can track the movement of bodies or specific body parts, capturing data on parameters such as position, velocity, and acceleration.
This method is extensively utilized in sports biomechanics to enhance athletic performance and reduce injury risks. In clinical environments, it supports the evaluation and rehabilitation of patients with movement disorders, aiding in the creation of tailored treatment plans. Integrating motion analysis with force platforms and electromyography allows for a holistic examination of movement, shedding light on the associated muscular activities and biomechanical forces.
The integration of artificial intelligence (AI) and machine learning is set to revolutionize motion analysis. Future developments aim to implement AI-based markerless tracking and pose estimation, which will simplify the data collection process and enhance the precision of movement analysis. These advancements are expected to expand the applicability of motion analysis across various disciplines, from sports science and medicine to animation and virtual reality.
Force Measurements
Force measurements involve quantifying the forces exerted by or on a biological system. This can be done using a variety of sensors and instruments, such as force plates, pressure sensors, and load cells. These tools capture data that can be analyzed to understand how forces are distributed across a system, how they vary over time, and how they contribute to the mechanics of movement.
Force Plates: These are platforms equipped with sensors that measure the forces exerted on them. When an individual stands, walks, or jumps on a force plate, it captures data that can be used to analyze gait, balance, and performance in sports.
Pressure Sensors: These sensors are used to measure the distribution of pressure across a surface. In biomechanics, they are often used to study foot mechanics and to design custom footwear and orthotics.
Load Cells: These devices convert mechanical force into an electrical signal. They are commonly used in biomechanics to measure muscle force, joint loads, and the forces involved in manipulation tasks.
Electromyography (EMG)
Electromyography is a technique used to measure the electrical signal that initiates muscle contraction. This signal is the so-called action potential (AP), which is conducted from the nerve cells via motor end plates to the muscle. It can be detected using electrodes placed on the skin or implanted in the muscle tissue. By analyzing these signals, researchers can gain insights into muscle function, coordination, and fatigue.
Surface EMG: This involves placing electrodes on the skin overlying a muscle. It is a non-invasive method used to assess muscle activity during various tasks, from simple movements to complex athletic performances.
Intramuscular EMG: This method involves inserting a needle electrode directly into the muscle tissue. It provides more precise measurements than surface EMG and is often used in clinical and research settings to study muscle function in detail.
Applications of EMG: EMG is used in a variety of applications, from sports science to rehabilitation. It can help to identify muscle imbalances, assess the effectiveness of training programs, and guide the design of prosthetics and assistive devices.
Computer Simulation and Modeling
Computer simulations and modeling are used to predict and analyze biomechanical phenomena. Researchers can create detailed models of biological systems and simulate how they would respond to different forces and conditions. This allows for the testing of hypotheses and the exploration of scenarios that might be difficult or impossible to study in vivo. One example would be to use and inverse dynamic model to calculate joint contact forces.
Material Testing
Understanding the mechanical properties of biological tissues is a critical aspect of biomechanics. Researchers might perform tests to measure the stiffness, strength, or elasticity of tissues. This information can then be used to inform computer models or to design medical devices and treatments.
Imaging Techniques
Imaging techniques such as MRI, CT scans, and ultrasound are used to visualize the internal structures of living organisms. This allows researchers to study how these structures deform under load, how they interact with surrounding tissues, and how they contribute to the overall mechanical function of the organism.
Conclusion
Biomechanics is a fascinating and diverse field that sits at the intersection of biology and mechanics. By applying the principles of mechanics to biological systems, biomechanics provides valuable insights into the structure, function, and motion of living organisms. Whether it’s enhancing athletic performance, designing medical devices, or advancing our understanding of cell biology, the applications of biomechanics are vast and varied. As technology continues to advance, the methods of biomechanical research will only become more sophisticated, further expanding the possibilities of what can be achieved in this dynamic field.
