Assessment of Running Biomechanics
Out of all the types of aerobic exercises, running is associated with the highest prevalence of overuse injuries, with the majority of these injuries occurring in the lower limb .
Running injuries occur as a result of cumulative stresses from forces placed on the body via intrinsic means (biomechanics, age etc) as well as extrinsic factors (training volume, nutrition, type of training etc) 
Running technique, as well as running biomechanics, have been shown to affect a runners performance . Evaluating Running Biomechanics and kinematic patterns can help to identify the forces placed on a runner as well as identify if these forces are potentially causing or aggravating their symptoms. A thorough biomechanical evaluation will enable the identify their problem areas as well as develop a comprehensive management plan to address any impairments observed. It is important to note that most of the research to date has been conducted on populations of non-symptomatic runners and as such one should keep in mind that these findings might not correlate directly with a symptomatic population. 
Running biomechanics observed on a treadmill have shown to be comparable to overground running. Using video analysis to evaluate kinematic patterns is an effective way to recognise various running styles and create a comprehensive management plan that addresses any biomechanical errors.
The video should ideally be more than 30 frames per second or greater than 120Hz to optimise analysis. The latest smartphone technology can do this so expensive equipment is not necessary for basic assessments.
3D video assessment is ideal as it allows you to analyse considerably more than simple 2D, however, in a basic setting 2D analysis has shown to be a reliable and accurate tool.
2-D video based running biomechanics analysis
Souza, 2016, provides a detailed breakdown of how to do a 2D video, running biomechanics analysis.
2 views perpendicular to each other are important to ensure you are evaluating every aspect of a running style. Lateral view and posterior view are typically done as a minimum but if you had the equipment you could also add other side and anterior view. Ideally one would use at least 2 cameras per view, with a whole body view as well as a zoomed in on the foot and ankle
Markers, usually some form of bright coloured stickers, are used to help analyse the video. Ideally they should be placed directly on the skin or alternatively, the runner should wear form-fitting running apparel with the sticker placed over their clothes. Markers can be placed on the following landmarks: C7 spinous process, posterior superior iliac spines, anterior superior iliac spine, greater trochanter, lateral knee joint line, lateral malleolus, the midpoint of the calf, superior and inferior portions of the heel shoe counter, head of the fifth metatarsal.
Biomechanical Observations on 2-D Video
The following kinematic patterns should be observed when analysing the video. At present, there are no set norms or ideal values and as such, every aspect should be analysed and then compiled into a “bigger picture” analysis.
Side View ·
- Foot strike
- Foot inclination angle at initial contact
- Tibial angle at loading response
- Knee flexion during stance
- Hip extension during late stance
- Trunk Lean
- Vertical Displacement of Centre of Mass·
- Base of Support
- Heel Eversion
- Foot progression angle
- Heel whips
- Knee Window
- Pelvic Drop
- Auditory (How loud are they landing)
- Shaking of treadmill
Common Running Styles
A systematic approach to identifying common running errors is to identify different running styles on video analysis . When assessing a runner for biomechanical errors it is important to use a combination of findings. There is no one finding in isolation that will provide you with enough information to develop a comprehensive management plan.
Overstriding is a pattern of running where the initial contact of the foot on the ground is in front of a person’s centre of mass.
Overstriding is different from a long stride length. The length of the stride may be long but if the foot is landing in the appropriate position it does not cause the high forces that increase the risk for overuse injuries .
Overstriding is an energy inefficient way to run. It results in increased ground reaction forces, braking forces and joint loading all of which can contribute to tibial stress fractures as well as anterior knee pain
Signs of Overstriding on Lateral 2-D Video Analysis 
A vertical line drawn from lateral malleolus falls anterior to the pelvis (ideal is when the line falls within the runner's pelvis i.e. the foot is landing under the centre of mass) Increased Foot inclination angle at initial contact Small Knee Flexion angle at initial contact (More extended knee at initial contact)
The collapser is best viewed posteriorly. The Collapser will have a Trendelenburg gait as well as a dynamic genu valgum with excessive hip adduction, internal rotation as well as knee valgus. The primary driver of the problem can either be proximal (lumbopelvic control) or distal (reduced ankle range of motion) and a thorough examination needs to be done to determine the cause. They will often complain that they kick their shins or that their knees knock together. This inward collapsing is often seen in runners complaining of anterior knee pain and lateral hip pain.
Video: Excessive hip adduction
Small or no Knee Window Excessive Pelvic Drop Excessive Heel Eversion (difficult to measure on 2-D Video)
The Weaver is a runner whose legs cross the midline excessively while running this is also known as a tightrope gait. Running with a narrow base of support or the legs often occurs as a compensatory result of other biomechanical inefficiencies such as a dynamic genu valgum . Crossing the midline whilst running can result in ITB problems as well as increases the risk of tibial stress factors. In a runner with asymmetry one leg may tend to drift inward more than the other and this is often the symptomatic side 
Video: Narrow Step Width
Signs of “Weaving” on 2-D Video Analysis
Narrow base of support or feet crossing midline (“scissoring gait”) Excessive Arm swing (compensatory mechanism)
The Bouncer is a runner who has excessive vertical oscillation during running. This means they move up and down too much, rather than forward. They may also have a very heavy landing and have a loud foot strike. This is a very inefficient way of running and requires a lot more energy from the runner . A large centre of mass excursion has been shown to increase ground reaction forces tremendously as well as joint load . This puts the runner at high risk for joint injuries as well as tibial stress fractures. . Wearables such as Garmin watches now have the technology to measure vertical oscillation while running
Video: Increased Vertical Oscillation
Signs of a “Bouncer” on 2-D Video Analysis
Increased or excessive vertical displacement of the centre of mass “Heavy landing” or loud landing
The Glut Amnesiac
The Glut Amnesiac is so named because they normally have weak posterior musculature (gluteal complex or trunk extensors) and as such adopt a more upright or leaning back posture to reduce the demand on these structures. This, however, places a lot more demand on the anterior structures. The posture itself can also lead to overstriding and the associated increased ground reaction forces and joint loading.
Video: Upright Running Posture
Signs of a "Glut Amnesiac" on 2-D Video Analysis
Upright running posture Low trunk lean angle
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