Running Mechanics for Clinicians

Original Editor - Mariam Hashem

Top Contributors - Mariam Hashem, Kim Jackson, Tarina van der Stockt, Jess Bell and Robin Tacchetti

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Overview of Running Injuries

Lower extremity running-related injuries range from 19.4 to 79.3 percent. The most common injnuries are:

• Patellofemoral pain
• Medial tibial stress syndrome (shin splints)
• Achilles tendinopathy
• Iliotibial band syndrome
• Plantar fasciitis
• Stress fractures of the metatarsals and tibia

Hamstrings and calf problems were reported by men marathon runners, while hip pain problems were common among women. Most of these injuries have a high recurrence rates.

A 2015 systematic review of 15 studies identified different risk factors for women and men:

	Women	Men contributing factors to tissue stress
	Age	History of previous injury
	History of previous sports activity	Running experience for 2 years
	running on a concrete surface	History of previous injury
	Participating in a marathon	Average weekly running distance (20–29 miles)
	weekly running distance (30–39 miles)
	wearing running shoes for 4 to 6 months

Stress Frequency Model

Running Injuries are caused by an inter-relation of multiple factors. A simple injury causation model using the stress frequency curve can help us to develop an idea on the contributing factors and how to address them in the management plan.

A tissue is influenced by the applied stress and the frequency of application. If the stress and it's frequency are below the injury threshold, the tissue will function normally within it's capacity. However, if either or both of these factors exceeded the injury threshold, the tissue is moer likely to be injured. This explains why some runners may not experience injury for long time and develop one as soon as they increase their frequency of training such as training for a marathon.

Considering stress and frequecny is important to understand individual tissue's capacity.

Running mechanics influence the stress applied to the body, magnitude, type (bending, shear or tension) and the speed of application on each foot contact. Assessing running mechanics leads us to think about the stressed structure and explains the presented symptoms. For example; landing on toes -forefoot strike- results in greater stresses on achillies tendons and the calf muscle forces.

Assessing frequency of running and training volume to understand the effect of the accumulated tissue stress . If falling below the tissue's threshold the likelihood of developing injury will be low and vice versa. Subjective examination can help us to understand the frequency, ask your client about them about their weekly training and what is your standard trainig like? How much running they do? what wa the frequency of applied stress before the injury occured?

the next thing is wehre is identifying the injury threashold which refers to the interaction between the tissue capacity to tolerate the stress an the tissue capacity to tolerate the frequncy of the applied stress. Tissue capacity refers to the functional capabilities of a specific tiussue to cope with stress type and frequency. A muscle capable of producing high peak force may be able to tolerate high level of stress on an individual foot contact. On the contrary , if the mscule's capability is low, applying stress with high frequency the muscle may not be able to cope well leading to injuries. To translate this into practical application, when assessing a runner we should think of adjusting the mechanical pattern or push up the tissue's endurance to tolerate the applied load. Lowering the applied stress by reducing the amoint of running can be a method of off-loading the injured tissue while building up the tissue resileince to cope with the functional aspiration.

Clinical Running Assessment Set Ups

Many of the common running-related biomechanical patterns can be identified by 2D analysis using inexpensive tools^[1] such as a mobile phone or tablet camera. Satndaridizing the method of assessment is improtant for accuracy of identifying the patterns and to make sure your findings are not due to viewing angles.

Settings:

Tools/equipment: High speed camera or mobile phone/table camera and a tripod.

Distance: 1.5-2 meters from the treadmill

Height:0.8-1 meter-pelvic height

Views: side (saggital) and rear (frontal)

Timing: initial contact and mid-stance

Joints/regions: thorax, pelvis. hips, knees and ankles.

Follow a structured process of assessment by looking at one joint/region at a time. To end up with a structured problem list, slow down the speed of the camera to allow you to go backward and forward and take still pictures to draw lines and identify areas of stress.

Common Mechanical Patterns

Bramah et al found that similar mechanical patterns were associated with multiple injuries.

Looking from the saggital plan, we can identify the following patterns:

1- Foot Inclination Angle at Initial Contact:by drawing lines to compare the angle between the sole of the shoes and the treadmill. A great angle indicates greater foot inclination. It can potentially be caused by rear foot strike if the runner's toes are too high compared to the heel or a forefoot strike when the inclincation is mainly due to a high angle at the heel. Neither strikes are considered to be superior to the other. Landing with high inclination will limit the ability to engage in dorsiflexion which serves as shock absorption. High inclined foot will take longer time to get the foot flat on floor to start the shock absorption mechanics resulting in high impact vertical loading. Fig 3 in the study by Souza RB shows how to identify foot inclination.

Conversely, landing with forefoot strike (on tip-toes) allows less time to engage in dorsiflexion utilizing the calf complex and possibly stressing the achillies tendon. Refer to this link to see the difference between different foot strike patterns.

In the management plan, a relatively low inclincation angle where foot is low to the ground regardless of the type of strike (heel or toe) minimzes the stress on achillies for forefoot runners or engage dorsiflexion for heelstrike runners.

2- Knee flexion angle:

Initial conact: draw a line straigh thruoogh femur, then down to floor. another one through lateral condyle of femur to laterl malleoulus. the greater the angle indicates more knee flexio. the smaller knee extension.

The injured runners tend to land with more knee extension at intial contact- influencing tissue stress- impact the ability to absorb shock. knee and ankle dunction as suspensions as you run, if you can land with knee in flexion and foot flat on floor you can start to engage you suspension spring form the moment you touch dow. that can serve as you move to the mid stance. running with extended knee and high inclined foot they are less likely to engage the shock absorption mechanism within knee and ankle- more higher shock , breaking forces as they land.

Mid stance: lines drawn across foot (floor- from malleouli up to epicondyle: dorsiflexion looking at line drawn from femur compare to shin line- knee flexion?

Mid stance: shock absorbed when hitting ground. Utilizing knee flexion to absorb shock.

Landing w extensio an dhigh inclined foot and has a huge range of flexion. using it to absorb shock, how it stresses tissue? Eccentric demand placed on quads in stance phase resulting to injury PFP, quads overloaded. conversely: hitting ground with small flexion, small dorsiflexion: poor ability to absorb shock- hear them on treadmill. minimal movment in knee ankle complex. suspension is not good- not absorbing shock- more forces to body- compensatory pattens on frontal plane: further injuroies. elevated shock: high impaact: global injury developmene+ s tress fracture. hear them on treadmill: poor ability to bed the knee. why they are not able to exccentrically absorb ? function prespective: gait training or strength prespective?