When comparing the measured differences between modes of locomotion, empirical results (Arata, 1999; Bates, et.al, 1986a, 1986b, Devita &
Stribling, 1991, Sveistrup & Bates, 1991) have shown that there are numerous performance differences. In comparing forward and backward walking, it has been shown that backward walking results in:
- A more erect posture (less trunk inclination) than during forward walking of running
- Reduced overall range of motion at the hip joint (greater flexion and lesser extension);
- Reduced overall range of motion at the knee joint (increased active functional range)
- Increase stride rate, decreased stride length and increased support time;
- Elimination of eccentric knee joint flexion (knee joint exhibits greater flexion at touch down followed by a nearly isometric/fixed position during the initial stance phase);
- Role reversal of muscular structure supporting the ankle and knee joints (knee joint served as primary power producer while ankle joint primarily absorbed shock);
- Modification of lower extremity muscular activity.
Many of these kinematic differences also hold true when comparing backward walking. Additional documented biomechanical differences (Grasso, et al., 1998) between directions of walking include:
- Direction of knee joint shear force is reversed (initially backward during forward walking while directed initially forward during backward walking);
- Vertical contact force is greater at contact while forward walking versus push-off in backward walking which states that vertical forces are reduced tremendously. ( backwards)
- Electromyographical (muscle) activity of the lower extremities is greater in backward versus forward walking, suggesting greater energy expenditure; ( more calories burned)
- Muscle activity patterns are unique for each direction of walking.
In addition to the biomechanical differences of walking backwards there are
*Increased physiological demands that have been documented.
For example, Flynn, et al. (1994) indicated that during backward walking, VO2 and heart rate were 78 and 47% higher than during matched speed forward walking, respectively. These data clearly identify that inclined backwards walking generates a greater stress to the cardiovascular system.
The increased physiological demands on the human system can be viewed as a benefit for the high-level athlete interested in alternative training methods to their activity-specific training routine or for the recreational athlete or individual interested in burning more calories in a lesser time. In addition, the increased physiological demands in backward vs. forward walking can be of benefit in the rehabilitation environment, when one is interested in spending lesser activity time (due to injury) while expending a greater number of calories.
In order to walk backwards efficiently, kinesthetic sense is developed and balance is enhanced. This is not unlike learning to walk (forward) on a treadmill. When first walking (forward) on a treadmill, there is a tendency to hold onto or touch the rails to assist with balance. Eventually, one develops the balance skills and is able to walk without use of the rails. The same is true in learning to walk backwards. Balance skills are necessarily developed in order to complete the task (walking backwards) without rails or other forms of support. This enhancement of balance can be especially important for a vulnerable population, such as the elderly, who typically experience more falls as they age. We believe a walking program which includes backward walking can greatly enhance the balance and dynamic equilibrium of the participant.
Consequently, the force imparted to the body at impact is less in walking backward compared to jogging or running. This alone can be a benefit if one is
Suffering from an impact-type injury which could manifest as a sore knee, stress fracture, low back pain, or similar problem. To this end, walking backward could be a means to maintain cardiovascular fitness quicker (recall physiological benefits previously discussed) without risking further force-related trauma to the lower extremities.
Backward walking can potentially provide unique benefits to the individual rehabilitating an injury as well as to the exercise enthusiast who is facing the inevitable effects of age on the body. Backward walking trains the (rotator cuff) and patella stabilizer of the knee. Some of these benefits include similar patterns of vertical and anterior posterior ground reaction force during the support phase with no comparatively excessive loads.
This also provides increased hamstring stretch during the stride and enhancement of proprioception / balance control.
A treadmill with rails can be used, however it is less effective.