The background: Musculoskeletal skeletal loading and bone adaptation.
The musculoskeletal tissues in our bodies such as bone, muscle, tendons, and cartilage all respond to a wide range of stimuli as we live our day to day lives. This is well known when it comes to muscles, most people have at least a basic understanding of how to train and what to eat to stimulate and support muscle growth.
Like muscles, bones get stronger or weaker in response to stimuli, this is known as the osteogenic response though the outcomes are not visible in the same way. Bones do not change size, instead they increase or decrease their bone density, or bone mass. A healthy bone, as seen below has a high density of calcium and minerals, providing the strength and structural integrity needed to support the human body in most activities. However, without the right conditions and stimuli we experience bone loss; where our bones lose density making them more prone to wear, breaks and fractures as they lose their structural integrity.
The real issue here is that, because these changes are invisible to the naked eye most people do not know they have a degenerative bone disease such as osteoporosis or osteoarthritis until they are in pain or worse there is a fracture or break.
The human body regulates bone density through two distinct bone adaptation processes; bone modelling, in which the bone mass and strength is increased, and bone remodelling, in which bone mass is conserved or reduced. As with muscles there are multiple variables that can stimulate or hinder these bone adaptation processes, i.e. diet, hormones, exercise etc.
When we move or exercise, we put a load on our skeletal system, known as musculoskeletal loading. This mechanical stimulus induces a stress on our bones, the act of bearing weight compresses the bone structure slightly and triggers the cells in the bone to assimilate more calcium and other minerals; encouraging bone adaptation and ultimately increasing bone density.
However, not all exercise is equal. Research has shown moderate to vigorous weight bearing exercise and high impact activities are required to develop and maintain healthy bones. These are known as osteogenic, or weight bearing activities and include activities such as running and jumping.
Extensive research has led to the development of the osteogenic index; a means to assess the effectiveness of different exercise protocols; linking skeletal loading to bone adaptation. This bank of research highlights the three key contributing factors of skeletal loading:
Using these factors, we can assess and manipulate the loading profile of different exercises, interventions, treatments and countermeasures; considering the loading intensity (magnitude x frequency) and loading dose (intensity x duration).
In its simplest form, a higher loading intensity is better for bone adaptation, but this is a double edged sword. Those suffering from degenerative bone disorders or recovering from surgery or a traumatic injury lack the structural integrity to perform high intensity activities without putting themselves at risk of further injury. A risk compounded by cumulative loading; introducing fatigue as the loading dose increases over time.
To combat degenerative bone diseases and effectively recover patients after a traumatic injury or surgery, while mitigating these risks it is vital to that skeletal loading is introduced in a controlled manner. This controlled loading allows patients to maintain a safe level of loading during rehabilitation while gradually increasing the loading intensity and duration of activities their loading capabilities recover.
Healthcare professionals are adept at managing patients today but there is a lack of real, unbiased data to help inform their decision making. The is especially true in the early stages of degenerative bone disorders or later stages of rehabilitation where a drop in weight bearing capability or offloading are hard to identify with the naked eye.
Our Algorithm
Born out of osteoporosis research and an assessment of how the loading intensity of physical activities impacts bone adaptation, our solution and proprietary algorithm provide a novel way to quickly and easily assess musculoskeletal loading.
The loading algorithm replicates the research and maths behind the osteogenic index; using acceleration as a surrogate for force. Accelerometers attached to the body capture the loading magnitude, frequency and duration and this data is used to calculate the Loading intensity (Body Weights / second) and the Loading dose in near real time.
Our two-sensor system, collecting accelerometer data from each ankle, is ideal for measuring and monitoring dynamic weight bearing capabilities, assessing how well patients are bearing weight and how they are distributing that weight across limbs. These two simple metrics enable progress to be tracked across recovery; engaging patients in the process, supporting the education of controlled loading and promoting positive patient outcomes.
The system also presents significant opportunities for further research into musculoskeletal loading and the maintenance bone integrity, as well as other tissue such as muscle, tendons, and cartilage.
Researchers can assess loading contribution in 3 axes of motion, various frequency bands and separate activity phases such as swing vs stance phases of gait to explore and profile exercises, interventions, treatments and countermeasures, investigate personalisation and identifying high risk patient groups or take a deeper dive into the loading factors that contribute to bone adaptation.
Comments