Running
Descriptors
There are many spatial and temporal descriptors for running:
- Stride rate
- Step width
- Foot angle
- Running speed
- Running pace
Stride length
Stride length refers to the distance between successive ground contacts of the same foot1.
Taller, heavier, or disproportionately long legged individuals tend to prefer a longer stride length at a given running speed, but Neumann1 claims that there is poor evidence for changing stride length based on anthropometric properties1.
Stride time
Stride time (\(\frac{\textrm{Time (seconds)}}{\textrm{Strides}}\)) refers to the time between successive ground contacts with the same foot1.
Stride frequency
Stride frequency (\(\frac{\textrm{strides}}{\textrm{seconds}}\)) is the inverse of stride time and represents the number of strides per second1.
Step length
Step length refers to the distance between successive contacts between opposite feet1.
Step time
Step time refers to the time between successive contacts of opposite feet1.
Step width
Step width refers to the distance between the opposite feet in the frontal plane1. This only takes into account frontal plane distance and not the distance in the sagittal plane.
When progressing from walking to running to sprinting, the step width should decrease and then become negative as a crossover gait pattern is utilized1.
Foot angle (Toe-out)
Foot angle (also known as angle of toe-out) refers to the amount of foot abduction from the line of progression1.
| Activity | Foot angle |
|---|---|
| Walking | 4-9°1 |
| Running | 5-7°1 |
Running Speed
Running speed is generally reported in \(\frac{\textrm{Meters}}{\textrm{second}}\) or \(\frac{\textrm{Miles}}{\textrm{hour}}\)1. Running speed is often calculated as the total distance of the run over the total time running.
Running pace
Running pace is used by runners and coaches as a metric for training more often than running speed1.
Stride Cycle
The stride cycle is a fundamental metric for running. The stride cycle is contains all motions/events that occur between the same event occuring twice on one side. Generally, it is categorized from ground contact on one foot to ground contact again on the same foot1.
Gait patterns use the term “heel strike,” but in running, the term “ground contact” or “foot strike” is used since initial contact can occur at the rearfoot, midfoot, or forefoot1
Exercises
ABCD Motions
B Motion
ABCD Drills
“Aside from strength training, how can one improve running form and performance? Because running involves a neuromuscular component, running form can be improved through specific form drills that coordinate the movements of the involved parts of the anatomy. The drills, developed by coach Gerard Mach in the 1950s, are simple and cause little impact stress. Essentially, these drills, commonly referred to as the ABCs of running, isolate the phases of the gait cycle: knee lift, upper leg motion, and push-off. By isolating each phase and slowing the movement, the drills, when properly performed, develop the runner’s kinesthetic sense, promote neuromuscular response, and aid in strength development. A properly performed drill should lead to proper running form because the drill becomes the running performance—just at a faster velocity. Originally, these drills were designed for sprinters, but they can be used by all runners. They should be performed once or twice per week and can be completed in 15 minutes. Focus on proper form.”3
A Motion
“The A motion (figure 1.2a, b, and c) is propelled by the hip flexors and quadriceps. The movement can be performed either while walking or, more dynamically, as the A skip or A run. The movement involves knee flexion and forward rotation of the pelvis (figure 1.2c). Meanwhile, the arm carriage is simple and balances the action of the lower body rather than propelling it. The arm on the opposite side of the raised leg is bent 90 degrees at the elbow; it swings forward and back like a pendulum while the shoulder joint acts as a fulcrum. The other arm moves simultaneously in the opposite direction. Both hands should be held loosely at the wrist joints and should not be raised above shoulder level. Emphasize driving down the swing leg, which initiates the knee lift of the other leg.”3
A Walk (drill) A Skip (drill) A run (drill)
B Motion
“The B motion (figure 1.3a, b, and c) depends on the quadriceps to extend the leg and the hamstrings to drive the leg toward the ground in preparation for the impact phase (figure 1.3c). In sequence, the quadriceps extend the leg from the position of the A motion to potential full extension, then the hamstrings group forcefully drives the lower leg and foot to the ground. During running, the tibialis anterior dorsiflexes the ankle, which positions the foot for the appropriate heel landing; however, dorsiflexion should be minimized in the B motion so that the foot lands closer to midstance. This precision reduces the impact experienced by the heel; in addition, because the biomechanics of the foot are less involved here than in running, this motion does not promote forefoot injury.”3
B Walk (drill) B Skip (drill) B run (drill)
C Motion
“The final phase of the running gait cycle is dominated by the hamstrings (figure 1.4a and b). When the foot makes contact with the ground, the hamstrings continue to contract, not to limit the extension of the leg but to pull the foot upward, under the glutes, in order to begin another cycle. Accordingly, the emphasis of this exercise (figure 1.4b) is to pull the foot up, directly under the buttocks, thus shortening the arc and the duration of the phase so that another stride can be commenced. This exercise is performed rapidly, in staccato bursts. The arms swing quickly, mimicking the faster movement of the legs, and the hands come a little higher and closer to the body than in the A and B motions. This motion is also facilitated by a more pronounced forward lean of the torso, similar to the body position used in sprinting.”3
C Walk (drill) C Skip (drill) C run (drill)
D Drill
D Walk (drill) D Skip (drill) D run (drill)