Clinical Use of Gait Analysis for the Athlete

Fig. 4.1

2D video gait analysis. Photo courtesy of The Running Institute

Since most clinicians are likely to use in-office VGAs to assess their athletes, a suggested guide to obtain an optimal VGA is provided. An example schematic of a 2D VGA setup is noted below (Fig. 4.2).

Fig. 4.2

2D VGA office setup schematic. Illustration credit The Running Institute

Important Guidelines for in-office VGA:

1.

It is important to provide a proper sized surface to allow the athlete to run without feeling constricted or confined. The treadmill should have a deck surface between 45–60 in. long and 16–20 in. wide. For tall or competitive runners, the length may be more than 60 in. to allow for longer stride length to occur.
2.

There should be no visual obstructions to the camera (i.e., side handles, braces, or cords) along with a clean background to avoid image interference.
3.

There should be a way to measure a standard distance for analysis. Many systems have a measuring device imbedded in the software to account for this.
4.

For optimal VGA capture, to reduce the blurring and elimination of shadows, use LED lighting.
5.

When performing VGAs, the camera angle can affect the outcome of the angles being drawn and assessed. The camera should be placed on a stationary location to the treadmill at 90° to the subject being captured.
6.

Skin markings should be added prior to the assessment for better bisections to allow for better angular measurements.
7.

The athlete should warm-up prior to video capture to find a comfortable pace and speed for the assessment.
8.

The runner should find a comfortable and consistent running speed.
9.

The clinician should determine whether they would like a full body versus anatomic regional assessment [18].

Excellent examples of lateral, posterior, and anterior camera angles of the lower body are noted (Fig. 4.3a–c). Photo credits Paul Langer.

Fig. 4.3

Lateral camera angle (a). Anterior camera angle (b). Posterior camera angle (c)

Peak Pressure Analysis

The pressure analysis is valuable for obtaining the peak pressures throughout the gait cycle. This can help identify areas of abnormality at the different points of pedal contact. From this information, the clinician can develop the correct methods in biomechanical control from the use of orthotics, shoe wear, and muscular reeducation [19].

For the longest time, floor plate mounted 3D force plates were used to determine ground reaction forces and calculation of joint moments via inverse dynamics. The trending focus has been on creating more portable solutions operated via shoe-insoles based on pressure distribution. Instead of in-shoe sensors , the newest way to capture pressure measurements is the use of treadmills with either 3D force plates or pressure plates. There are limitations that are noted with this technology. The findings are that portable solutions cannot measure forces in 3D and certain restrictions in joint force or moment calculations have to be considered (Fig. 4.4).

Fig. 4.4

Peak pressure analysis with in-shoe pressure sensors. Photo credits Teksan

Human Motion Analysis

VGAs have now evolved to include the use of electromyography and ground reactive forces using force plate technology. Human motion analysis is more comprehensive and is inclusive of:

Human motion analysis can be separated into three major measurement areas :