Motion Capture

Motion capture forms the foundation of human movement analysis. It encompasses any technique or method which records human movement. These can include optical and sensor- based approaches. Principia is at the forefront of sensor-based motion capture, which provide technologies that allow motion capture in any environment. Principia is a strong advocate and user of the Xsens MVN system, an inertial sensor-based system.

The Xsens MVN system consists of a set of inertial measurement units (IMU’s) placed on the human body segments. Each IMU consists of an accelerometer, gyroscope and magnetometer, through a process of sensor fusion, these signals calculate an orientation, or how something is positioned/directed in space.

These orientations are applied to an underlying biomechanical model with each sensor representing the orientation of its corresponding body segment. Once the model is scaled and calibrated to the individual, complete human motion measurement can be performed of a human. Most recently, the latest engine also integrates GPS signals to allow position aiding.

Muscle activation analysis (Electromyography)

Electromyography (EMG) is the field dedicated to measurement of the electrical activity of muscle. The musculoskeletal system is governed by the nervous system through a series of afferent (sensory) and efferent (motor) neural signals. Essentially, an efferent electrical signal is sent to the corresponding muscle that can produce a given movement or stabilization, initiating muscle activation and the onset of force.

EMG’s provide a method of measuring this activation and holds valuable information in muscle activation patterns, as well as the degree of muscle co-contraction that occurs at joints. Principia Technology has the ability to perform laboratory EMG, as well as portable EMG out in the field. Such knowledge allows one to see asymmetries in muscle activation profiles, which may indicate onset of fatigue.

Electromyography (muscle activation analysis)

Foot Pressure analysis

Pressure insoles have the ability to be placed inside shoes to record real time plantar pressure of the foot. Such analyses have important applications in medical diagnostics, rehabilitation and sports related performances. Special ultrathin sensors act to measure and analyse force distribution in the foot, and can establish important parameters of foot biomechanics.


Dynamometry is considered the gold standard for strength testing. An isokinetic dynamometer is a device used to test the torque (rotational strength) and power of different muscle groups. It is used for clinical tests, as well as sport and exercise science applications.

It is useful to record strength throughout a joint’s range of motion, and can determine ratio’s of any joints agonist/antagonist muscle groups.


Body Composition Analysis​

Through the use of Dual Energy Xray Absorptiometry (DEXA), a complete breakdown of your body composition can be established. From these scans, bone mineral density can be measured, as well as the exact mass of bone, muscle, and fatty tissue in the body.

This can further be used to track bone mineral densities, as well as the percentage of body fat and amount of lean muscle tissue in the body.

Body Composition Analysis​​

Musculoskeletal modelling

Generate detailed analysis of what your body is doing at the musculoskeletal level. Understand what forces your muscles are producing, and what loads travel through your joints.