31 March 2021

Movement is prevalent in everything that you do, from voluntary contractions, which are produced consciously (like when you tell your body to move a finger to pick up your phone), to involuntary contractions, like your heart beating or food digesting. Your body’s ability to move well and efficiently as you age can have an enormous impact on your physical attributes, competence to perform, posture, and health. Limited movement due to environmental factors, lifestyle, or physical impairments can influence the body and how it moves in your day-to-day life. Learning to understand how your body moves, or how to improve these behaviours, can be beneficial to maintaining movement over your lifetime. The French philosopher and scientist Blaise Pascal famously said, “Our nature consists in motion; complete rest is death.” Movement is now more important than ever, as current lifestyle practices have evolved for us to lead very sedentary lives, which is affecting our overall long-term health. 

The study of human movement, known as kinesiology, looks at both the science and art of movement and spans hundreds of years. Kinesiology incorporates knowledge about biomechanics, anatomy and physiology, psychology, motor behaviours, and motor skills. The study of movement has a place in many professions, from sport-specific training in the health and fitness sectors to rehabilitation and physical therapy, as well as engineering and education applications. Understanding movement and the associated muscle and joint actions has a place in the world of personal training, so we can understand how the body is capable of moving under load. As you progress through life, the physical skills you learn (such as crawling, running, kicking, throwing, and jumping) all impact your motor learning and behaviours. These skills can be impacted by your anatomical or genetic make-up, physical abilities, and competency.

Planes of motion:

As described on the learning platform, the body can be sectioned into three planes. These planes run perpendicular to one another and intersect in the middle of the body; this point is known as the centre of mass (Hall, 2015). The sagittal plane cuts the body into left and right halves, the frontal plane cuts the body into front and back, and the transverse or horizontal plane cuts the body into top and bottom halves and is responsible for rotational and limb movements parallel to the horizon. These planes split the body into equal halves of mass and aim to describe movement in a specific direction around the body’s axis of rotation, which is perpendicular to the plane. Each of these planes has different descriptors to identify the direction of movement occurring at the joints. These are described as follows:

The Sagittal plane:

 describes movements including flexion (decreasing angle of a joint, bending parts together), extension (increasing the angle at a joint,) and hyperextension (past the comfortable end range of motion) and can occur at the shoulder, elbow, wrist, hip, knee, ankle, and spine. Movements at the ankle also occur in the sagittal plane, dorsiflexion (toes raising up, the angle between the foot and shin bone is decreasing) and plantarflexion (toes pointing down, the angle between the foot and shin bone is increasing). Movements in this plane can include elbow flexion and extension during a bicep curl, knee flexion and extension during a hamstring curl, and multi-joint movements, such as a narrow stance squat which involves flexion and extension at the hip, knee, and ankle. 

The Frontal plane:

 describes movements including adduction (limb moving towards the body), abduction (limb moving away from the body), spinal lateral flexion (side bend through the spine), elevation (raising up, superior) and depression (pushing down, inferior) of the scapula, ulnar deviation (little finger moving towards the wrist) and radial deviation (thumb moving towards the wrist), foot eversion (twisting out) and foot inversion (twisting in). Movements in this plane can include shoulder adduction and abduction during a lateral shoulder raise, lateral spinal flexion and extension during a KB windmill, or waving your hand using ulnar and radial deviation. 

The Transverse/Horizontal plane:

 describes movements including rotational movements around a longitudinal axis (left or right), or movements occurring when the arm/thigh is flexed, and the movement of the limb occurs from an anterior to lateral position relative to the horizon. Movements in this plane can include spinal rotation during a bicycle crunch/Russian twist, or turning your head left to right. This plane also describes horizontal movements such as a bent-over row or push up, as the limb is flexed and moving perpendicular to the body/horizon. 

Single plane movements can be as simple as lifting a box from the ground, twisting around to look at the person behind you, or side-stepping someone to avoid bumping into them. All these actions occur in one of the planes of motion that you have learnt about on the learning platform. Can you identify which of these three actions fits into the sagittal, frontal, or transverse plane? 

That’s just the start, though; when small movements in different planes combine to form dynamic movement, how do you categorise these?

Application to resistance training:

Understanding the different anatomical and directional terms can help Personal Trainers to understand different movement patterns, which muscles and joints are required, and how best to cue these to implement correct and safe patterns. Below are a few practical examples of how you can apply this knowledge within the gym. 

During a loaded back or front squat, movement mainly occurs in the sagittal plane as the hips, knees and ankles go through a flexion extension movement. However, this movement can also be described as an anti-flexion movement at the spine to reduce the risk of collapse during the movement. If the back muscles have a poor ability to resist spinal flexion, this can result in a breakdown of technique or loss of stability and could lead to injury. During a squat, there will also be a degree of hip external rotation at the beginning of the exercise, dependent on the individual’s squat width and experience level. Hip external rotation is important to maintain during a squat movement to ensure adequate gluteus and psoas muscle activation and stabilisation, to avoid knee cave during the concentric aspect of a squat. Anti-flexion movements that focus on working the back musculature and deep core can include prone back extensions. On the other hand, anti-extension exercises can include resisted dead bugs and planks, and can benefit when completing push-ups to avoid the hip dropping if the core is engaged correctly throughout the movement. 

During an overhead pushing exercise such as a barbell shoulder press, you need to have a stable base with your core engaged, to reduce spinal extension (arching of the back). If you press overhead, but your core is not stabilised, you will end up arching and potentially twisting through your spine or hips, which can result in a feeling of instability or potential lower back injury. By training anti-extension movements and cueing core engagement during this exercise, you are able to create a stable and strong base for the shoulder to extend overhead in the sagittal plane, and potentially lift more weight in the long term. 

Lastly, combining one or more planes of motion into a movement will allow for this movement to become more dynamic and enable you to recruit more stabilising muscles, helping to enable a connection between body segments that can help with balance or transfer of power. For example, if you were to complete a reverse lunge with a lateral medicine ball twist to wall, you worked first in the sagittal plane and then in the transverse plane. The lunge movement is great for improving strength in the lower body with a unilateral exercise, and the medicine ball twist to wall incorporates a dynamic stability and rotational aspect to improve the connection between the lower body and the core musculature. 

By learning, understanding, and interpreting different movement patterns and their application to strength training, you will be able to better understand what should be moving and when, to best train and teach your clients in a gym setting. By first being able to understand these joint actions and associated movement terms, you will be able to analyse movement and provide your client with accurate information on how to best train to provide a stable and safe lifting environment, or to progress your client to lifting maximally in a safe environment to help maximise potential. 

Anatomical references to movement:

Movements that occur across different planes can be categorised as multi-planar. Sporting actions, such as a golf swing, or dynamic movements like jumping and throwing or reserve lunge into rotational band twist, are executed through a combination of movements and technique. They can be described through a combination of movement and directional descriptions that break it down into segments, so this can be learnt and sequenced properly to allow for efficient transfer of power. When you put these actions together, you can create movement, and with practice this can become fluid and efficient. Bowling overarm in cricket is a good example. This bowling action incorporates movement through the lower body stepping forward, rotation through the hips and torso, and the arm rotating through its full range of motion to develop speed and slingshot the ball forward. This action can be learnt in sequence, and through the use of anatomical terms and describing movement of joints and body parts, this can be practised over time to develop speed and skill of movement. 

Directional terms can be used to describe joint movements away from the anatomical position by describing changes in joint movement, body and joint positions, and axes of rotation. The anatomical position can be described by a person standing upright, head forward, arms hanging straight down by their sides, palms facing forwards. This position is used as a reference point for future movements, as the joint positions or range of motion are measured from this position. For example, by describing direction using medial, lateral, superior, inferior, prone, or supine, you can describe the direction of the body or joints during an action. 

Directional terms to describe movement can pair together a joint and a plane of motion movement to showcase the combined movement; for example, lateral spinal flexion describes a side bend through the spine. You can also add different prefixes to these terms to add further detail. For example, by adding ‘anti-’ to these descriptors, you are showing that you want to limit this action. When describing an anti-flexion or anti-extension movement, you are asking that the body, when going through a specific range of motion, should resist and brace against a force that is trying to flex or extend.

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References (textbooks):

Whiting, W., & Rugg, S. (2006). Dynatomy: Dynamic Human Anatomy. Human Kinetics, Champaign, IL. 
Hall, S. J. (2015). Basic Biomechanics (7th ed.). McGraw-Hill Education, NY, USA.