Backward Walking: Understand Function And The Associated Benefits.

Backward Walking: Understand Function and the Associated Benefits.
Janet S. Dufek, Ph.D., FACSM jdufek@unlv.nevada.edu Visiting Research Associate Professor, University of Nevada, Las Vegas Research Scientist, Human Performance & Wellness, Inc. Barry T. Bates, B.S.E., Ph.D. btbates@uoregon.edu Senior Scientist, Human Performance & Wellness, Inc. Professor Emeritus, University of Oregon AdjunctProfessor, University of Nevada Las Vegas Amanda Tritsch, A.T.C. tritscha@unlv.nevada.edu Graduate Assistant, University of Nevada, Las Vegas

Introduction Humans generally learn to walk and run in a forward direction with little difficulty. This is inherently logical since our field of view is in the forward direction. What about locomoting in the opposite direction, that is, walking backwards?What benefit(s) might backward walking offer the participant? In our laboratory at the University of Oregon, we started to investigate forward/backward walking (and running) in the mid 1980s. We were intrigued by anecdotal evidence suggesting that backward running and/or walking provided unique training and/or rehabilitative benefits. We have since biomechanically investigated these various modesof locomotion and can share the results of our various experiments, along with selected research results of other investigators. Bioimechanical Comparisons When one compares physical efforts of backward and forward running, runners typically perceive equal efforts during backward running at speeds of about 80% of those of forward running. One generally cannot run as fast backward as forward. Thesame is true for backward

walking; it is difficult to walk at the same speed forward and backward, for any given perceived effort. This is due in part to the anatomical construction of the body, as well as aspects of skilled/learned performance. There are anatomical constraints that limit the flexion-extension movements of the lower extremities. This can be understood by observing that theankle, knee and hip joints are not structurally mirror images on the anterior and posterior sides of the joints. For example, when standing erect, lift one leg and bend (flex) your knee. You will note a great range of motion, more that 90 degrees. Now, from the standing straight position, try to extend your knee. You might display motion of approximately 1 to 5 degrees, which is much less than in theother direction. In addition to joint range of motion constraints, for matched velocities of running, stride length is generally longer during forward running while stride rate is greater during backward running (Arata, 1999). These facts also influence joint kinematic differences observed when comparing forward and backward locomotion. Similar constraints exist for backward walking. Comparisonsof the lower extremity joint range of motion patterns for forward and backward motion are shown in Figure 1. Our laboratory work has shown that the support-swing ratio of a walking stride in backward walking is similar to forward walking: 60% support and 40% swing. Viewing Figure 1, we observe that functional opposition of motion occurs at the hip joint between forward and backward walking. Whenwalking forward, the hip joint exhibits extension followed by flexion during the support phase, whereas in backward walking, the hip joint is near full extension at contact and flexes throughout support, followed by extension in the swing phase. The knee joint motion between forward and backward walking can be viewed as quite similar, if one “timereverses” the support phase for backward. In otherwords, the patterns are reversed. In forward walking, the knee joint flexes, extends, and then flexes in support whereas in backward, the knee joint initially extends, flexes, and extends in support, prior to flexing and extending during swing (similar to forward). The range of motion of the knee joint is less in backward versus forward. Ankle joint patterns are also comparatively reversed. In...