3D gait analysis

3D gait analysis

Understanding what caused your injury in the first place is fundamental to putting it right and a state-of-the-art Run3D system is leading the way in biomechanical assessment.

Timeoutdoors' Andrew Risbey recently visited The Gait House when his training for an ultra marathon was becoming hampered by a persistent injury. Steve Williamson takes up the story...

Our primary goal is for everyone to experience the joy of running and Andrew came to us as he'd been struggling with what he thought was a back issue, but neither a physiotherapist or a chiropractor had been able to pin-point the exact root cause.

He hoped that the gait analysis might give some clearer and more precise indications and allow him to resume his training.

An accurate assessment of your biomechanics is very important when it comes to successfully preventing and treating musculoskeletal overuse injuries. In fact, understanding what caused your injury in the first place is fundamental to putting it right.

And our state-of-the-art Run3D system offers the most accurate assessment of running biomechanics that modern science is able to provide. It enables us to accurately identify the root-cause of an injury and address it immediately by recommending exercises to remedy it and help prevent re-occurrence.

We can also help those who are performing well and injury-free but simply want to be more efficient on their feet and make tweaks to achieve those “marginal gains”, giving them the edge on their competition.

And the fact that we can assess at a variety of speeds means that walkers and runners alike can benefit from a Run3D assessment.

The Run3D service analyses the way you move and is very different to the more traditional video-based assessments you might have seen at your local running store and other sports injury clinics.

We analyse your joint angles in three dimensions and this means we are able to detect problems that are impossible to detect by eye or by video. More often than not it is these subtle problems that have contributed towards or indeed directly caused your injury.

So back to Andrew and his video clip below illustrates the process. This is an extract of him on the treadmill as seen through the eyes of our cameras. Each sphere represents a marker placed on his lower limbs which is measured during the assessment to provide the data.

Looking at this in more detail, there are six main elements to an assessment:

1. Clinical History

We take a history to understand the injury, activity levels and goals. In Andrew's case he wondered if a back issue was affecting his gait - in actual fact a very different scenario emerged.
2. Marker Placement

A series of markers are accurately placed at strategic points on the lower limbs. Cluster markers are placed at the pelvis, the hamstrings and also the calf muscles. Small individual reflective markers are also attached at the hip, either side of each knee and either side of each ankle. Markers are also attached to the trainers. 
3. Data Collection

All assessments are conducted in neutral trainers, which we provide. Assessments can be carried out in your own footwear and results compared with the assessment in neutral trainers and with you carrying load. After warming-up, you walk and run at predetermined speeds on the treadmill for around two to three minutes whilst the infrared cameras measure the positions of the markers at a speed of 200 times a second. The marker positions are automatically input into a lower-limb model, which accurately calculates the joint angles at the pelvis, hips, knees and ankles in 3D. This is the most advanced form of motion analysis that is currently available.
4. Data Analysis

The joint angles are automatically compared to the world's largest biomechanical database so that we can instantly identify the biomechanical factors that are likely to be contributing to any overuse injury. 

We focus on foot/ankle, knee and hip, and then look at the functional outcomes - in total that's 34 points of reference. In the graphs below the blue dot is the left limb and the red diamond is the right. The ranges of "excessive", "ideal" and "reduced" motion are based on our normative database.

Foot complexPeak Pronation: How much the foot collapses inward.
Pronation Velocity: How quickly the foot pronates.
Time to Peak Pronation: The time it takes for the foot to reach maximum pronation.
Tibial Peak Rotation: How much the lower leg rotates inwards.
Rotation Velocity: How quickly the lower leg rotates inwards.

Knee complexPeak Knee Collapse: The amount the knee collapses inwards.
Knee Collapse Velocity: How quickly the knee collapses inwards.
Peak Knee Rotation: The amount the knee rotates inwards.
Peak Knee Flexion: The amount the knee flexes.

Hip complexPeak Hip Collapse: How much the hip collapses inwards.
Peak Hip Rotation: How much the hip rotates inwards.
Peak Pelvic Drop: With each step during gait, you spend time standing on one leg, which is called “single support”.
Peak Hip Extension: How far back the hip is extended at push-off.

Combining all the information of together produces a Functional Outcomes graph, which has the following four categories: 

Functional outcomesStride Width: The side-to-side distance between left and right footsteps.
Stride Rate: The number of strides (footstrike to footstrike) taken with each foot every minute.
Toe-out Angle: The amount the foot angles out or in while it is on the ground (i.e. duck-footed or pigeon-toed).
Heel Whip: During gait, the hip and knee internally rotate creating torsional or twisting forces. 
5. Interpretation

The infrared technology and software are based on decades of research from some of the world’s leading universities, including the University of Oxford and the University of Calgary - which means our analyses are based on real science and not guess work or "calibration by eye". 

So having measured the joint angles to within two degrees of accuracy, we then compare the gait - in this case Andrew's - to the world’s largest biomechanical database so that we can identify the most subtle abnormalities in running style. This allowed us to understand why he got injured and start to provide him with a long term, effective solution to the problem.

This process started immediately after the assessment as we went through the initial results on screen and then a couple of days later - when the comparison anaylsis has taken place - we produced a detailed six-page report, which highlighted the key finding:

"You are generally showing a more ‘unstable’ picture across the hip. The main observation here being that again bilaterally (both sides) things are not doing the same thing which is the most important factor to consider. Again, it is interesting to see that the Left side is a much steadier picture and the Right is more varied; as mentioned this is essentially an Antalgic gait, whereby the body almost builds in a limp to offload an already stressed joint."

6. Recommendations

We recommend a treatment programme based on the results of the biomechanical report. This might be strengthening exercises, referral to a physiotherapist, footwear/orthotics advice or a specific stretching routine.

For Andrew we have provided nine specific exercises for him to focus on straight away, using a ‘Green’ thera-band. They are best completed during the evening for maximum results and need to be done thoroughly to ensure optimal benefit (with ‘Form’ over ‘Speed’ the key).

Strengthening - Ankle inverters/everters, Hip Abduction (outward movement), Hip Adduction (inwards movement), Glutes, Core.

Flexibility - Hip Internal/External Rotators, ITB, Big Toe, Calves.

We also suggested a physio/sports therapist could assist with deep tissue massage to get everything moving well again and to compliment the strength and stretching he'll be doing.

We then invite all clients back for a re-assessment after approximately 6-8 weeks - this involves another full analysis on the treadmill to create a 2nd set of results which can be compared with the initial assessment to monitor progress.

If you are currently suffering with an injury or would just like a detailed gait analysis to help improve your running or walking, let us know and we can get more information sent through to you. We are also offering £25 off the initial analysis for timeoutdoors members.

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