Abstract
Instrumented gait analysis has evolved into a widely used tool to define and describe abnormalities of gait. It is used as a tool to enhance the performance in sports as well as to measure the effects of conservative or surgical treatment methods. Patients usually walk very slow during gait training, whereas normal data are obtained at regular walking velocity. This may lead to misinterpretations. The purpose of this study was to determine the effects of walking slow towards gait and to establish normal data for “walking slow” on a treadmill.
10 healthy volunteers with no known gait problem underwent training to accommodate to the conditions of treadmill walking. There were 5 females and 5 males. The mean age was 30 [range 22–56] years. Instrumented gait analysis was performed using a camera system (Motion Analysis Systems). Data obtained were processed by OrthotracTM and the proprietary software of our lab. During data acquisition participants were asked to walk at leisure velocity, then they were asked to slow down as much as possible.
The normal walking velocity of was 0,99 [range 0,78–1,16] m/s. When asked to walk as slow as possible the walking speed decreased to 0,29 [range 0,14–0,50] m/s. We noted a change in the ratio between swing and stance periods with less swing time, as well as a increase of double limb support time. Step length decreased. Changes in the pattern of motion included delayed and increased peak ankle dorsiflexion and decrease of ankle plantar flexion at initial contact. 3-D motion data for hip and knee also demonstrate noteworthy changes, generally resulting in a decrease of joint excursion.
Interpretation of gait data obtained from slow walking patients should consider the effects walking velocity. Locomotion therapy (e.g. for spinal cord injuries) should not force patients into motion patterns that are only found at faster walking velocities.
