Conference PaperPDF Available


Content may be subject to copyright.
Gait initiation in upslope walking
Lisa Claußen,
Gerda Strutzenberger, Maria Flecker,
Hermann Schwameder
Institute of Sports and Sport Science, University of Kassel, Kassel, Germany
Department of Sport Exercise and Science, Paris Lodron University of Salzburg, Salzburg,
Studies examining biomechanical aspects of sloped walking at different inclination angles have only paid
little attention to the initial walkway’s length and its influence on gait parameters [1]. Methodological
either treadmills [2, 3] or custom-built ramps [1,4-8] were used to replicate the gait on slopes. While ramps
allow for a genuine walking pattern and force plates can be included, their restricted walking space requires
considerations on where to allow participants to start and stop walking.
Gait initiation was examined in level walking by using different biomechanical parameters. Mann, Hagy,
White, and Liddell (1979) suggested that three steps were necessary to reach steady-state gait based on
changes in joint angles, muscle activity and force plate data. Breniere and Do (1986) found that steady-state
gait velocity was reached within the first step of gait initiation. On the basis of a mechanical energy analysis,
Miller and Verstraete (1996) supposed to take three full steps before recording data. Despite disagreement
on the number of steps necessary to reach speed steady-state in level walking, it is recommended for gait
analysis to allow participants at least three steps before and after data collection [12].
In fact, the issue of the number of steps necessary to reach steady state in sloped walking has not been
addressed. In existing studies, the number of initial steps before the foot under investigation steps on the
force plate differs between studies or is not clearly reported [7,13]. For instance, Kawamura et al. (1991)
prepared a 2 m level walking platform in front of the slope and at the top of the slope in order to exclude
acceleration at the beginning and deceleration at the end of walking. Lay et al. (2006) adjusted the starting
position so the participant’s third step struck the force plates. Alexander and Schwameder (2016) let their
participants take up to four steps before and after the measurement.
Due to altered requirements on the kinematics and kinetics during upslope walking in order to raise the
body, it is hypothesized that reaching steady-state walking is the more difficult the steeper the incline is
compared to level walking. Thus, we suggested that the number of steps necessary to reach steady-state
walking increases as ramp angle increases during upslope walking.
Therefore, the main purpose of this study is to determine when speed steady-state in slope walking is
reached measured by the relative chance in horizontal velocity and the resultant center of mass (CoM)
velocity. Based on the results, recommendation for the set-up of further investigations on sloped walking
regarding the initial walkway should be defined.
Fourteen healthy participants (24.5 ± 2.0 yrs) walked on a ramp (6m x1.4m) at level (0°) and three uphill
inclinations (+6°, +12°, +18°). Kinematic and kinetic data were collected using a motion capture system
(Vicon, Oxford Metrics Ltd. UK, 250Hz) and two force plates imbedded in the ramp (AMTI, Watertown, USA,
1000 Hz). The starting position was adjusted to contact the force plates with a) the first (left) and second
step (right) and b) the third (left) and fourth (right) step of gait initiation. The participants were asked to
complete three trials in each step condition of walking from the starting point until the end of the ramp
with self-selected speed. The relative change of horizontal velocity (∆vel
) and the resultant CoM velocity
) for each stance phase were determined. Additionally, temporo-spatial, kinematic and kinetic
parameters of the lower limb were calculated. Statistics were calculated using a Friedman ANOVA (factor:
steps) with pairwise comparison using Wilcoxon tests (p=0.05, Bonferroni corrected: p=0.016)
decreased significantly from step 1 to step 2 in all inclinations, and remained afterwards on average
between ± 0.05 m/s of relative horizontal velocity change (Figure 1). Adding the vertical component leads to
a significant increase in vel
between step 1 to 2, between step 2 and 3 and a significant decrease of
velocity between step 3 and 4. Step frequency showed significant increases between step 1 to step 2 and
step 2 to step 3 in all inclinations (Figure 2).
Figure 1. relative change of horizontal velocity for
each step in all inclinations
Figure 2. step frequency for each step in all
Uphill gait requires raising the knee higher than in level walking in order to allow for a safe forward swing of
the foot to be placed in the higher position. Furthermore, the CoM has to overcome the gravity and be
further raised upwards. As with inclined steepness a higher demand is placed on the coordination of the
neuromuscular system, this study aimed to investigate if the same pattern for reaching speed steady-state
occurs in uphill walking compared to level walking, which is important for the analysis of uphill gait. With
respect to the relative change of horizontal velocity, speed steady-state in upslope walking was reached
already after the second step in all inclinations. However, maximum velocity was reached in all inclinations
with the 3
step when the resultant velocity was analyzed. This might be due to the vertical component of
the uphill movement. The increase in velocity was mainly generated due to the increase in step frequency,
which showed significant increases between the 1
and 2
step as well as between the 2
and 3
while step length did not show any relevant changes within all four steps. Critically reviewing the data
collection set-up, it has to be noted that a functional gait asymmetry is discussed in able-bodied gait [15].
Hence, we cannot fully state that the differences between the steps are only due to the change in gait
velocity from standing to steady-state walking. Therefore, significant differences between the steps could
be partly a result of functional gait asymmetry. In conclusion, it seems that steady state was reached with
the 3
step and thus, this step seems to be appropriate to be used for uphill gait analysis in all inclinations.
The following decrease of vel
between -0.7 and -2.4% indicated a slight deceleration of the motion.
However, it yet needs to be investigated if this is in the range of limb asymmetry or might be related to the
specific situation of the ramp.
1. Redfern, M. S., & DiPasquale, J. 1997. Biomechanics of descending ramps. In Gait & Posture. 1997, 6, p.
2. Kang, J., Chaloupka, E. C., Mastrangelo, M. A., & Hoffman, J. R. 2002. Physiological and biomechanical
analysis of treadmill walking up various gradients in men and women. In European Journal of Applied
Physiology. 2002, 86, p. 503–508.
3. Kimel-Naor, S., Gottlieb, A., & Plotnik, M. 2017. The effect of uphill and downhill walking on gait
parameters: A self-paced treadmill study. In Journal of Biomechanics. 2017, 60, p. 142–149.
4. Kawamura, K., Tokuhiro, A., & Takechi, H. 1991. Gait analysis of slope walking: a study on step length,
stride width, time factors and deviation in the center of pressure. In Acta medica Okayama. 1991, 45 (3),
p. 179–184.
5. Kuster, M., Sakurai, S., & Wood, G. A. 1995. Kinematic and kinetic comparison of downhill and level
walking. In Clinical Biomechanics. 1995, 10, p. 79–84.
6. Lay, A. N., Hass, C. J., & Gregor, R. J. 2006. The effects of sloped surfaces on locomotion: a kinematic and
kinetic analysis. In Journal of Biomechanics. 2006, 39, p. 1621–1628.
7. McIntosh, A. S., Beatty, K. T., Dwan, L. N., & Vickers, D. R. 2006. Gait dynamics on an inclined walkway.
In Journal of Biomechanics. 2006, 39, p. 2491–2502.
8. Schwameder, H. (2004). Biomechanische Belastungsanalysen beim Berggehen. Spektrum
Bewegungswissenschaft: Vol. 1. Aachen: Meyer und Meyer.
9. Mann, R. A., Hagy, J. L., White, V., & Liddell, D. 1979. The initiation of gait. The Journal of Bone and Joint
Surgery. In American Volume. 1979, 61(2), p. 232–239.
10. Breniere, Y., & Do, M. C. 1986. When and how does steady state gait movement induced from upright
posture begin? In Journal of Biomechanics. 1986, 19, p. 1035–1040.
11. Miller, C. A., & Verstraete, M. C. 1996. Determination of the step duration of gait initiation using a
mechanical energy analysis. In Journal of Biomechanics. 1996, 29, p. 1195–1199.
12. Perry, J. (2003). Ganganalyse: Norm und Pathologie des Gehens (1. Aufl.). München, Jena: Urban und
13. Komnik, I., Peter, M., Funken, J., David, S., Weiss, S., & Potthast, W. 2016. Non-sagittal knee joint
kinematics and kinetics during gait on level and sloped grounds with unicompartmental and total knee
arthroplasty patients. In Plos One. 2016, 11(12), p. 1-18.
14. Alexander, N., & Schwameder, H. 2016. Lower limb joint forces during walking on the level and slopes at
different inclinations. In Gait & Posture. 2016, 45, p. 137–142.
15. Sadeghi, H., Allard, P., Prince, F., & Labelle, H. 2000. Symmetry and limb dominance in able-bodied gait:
a review. In Gait and Posture. 2000, 12, p. 34-45.
ResearchGate has not been able to resolve any citations for this publication.
Full-text available
After knee arthroplasty (KA) surgery, patients experience abnormal kinematics and kinetics during numerous activities of daily living. Biomechanical investigations have focused primarily on level walking, whereas walking on sloped surfaces, which is stated to affect knee kinematics and kinetics considerably, has been neglected to this day. This study aimed to analyze over-ground walking on level and sloped surfaces with a special focus on transverse and frontal plane knee kinematics and kinetics in patients with KA. A three-dimensional (3D) motion analysis was performed by means of optoelectronic stereophogrammetry 1.8 ± 0.4 years following total knee arthroplasty (TKA) and unicompartmental arthroplasty surgery (UKA). AnyBody™ Modeling System was used to conduct inverse dynamics. The TKA group negotiated the decline walking task with reduced peak knee internal rotation angles compared with a healthy control group (CG). First-peak knee adduction moments were diminished by 27% (TKA group) and 22% (UKA group) compared with the CG during decline walking. No significant differences were detected between the TKA and UKA groups, regardless of the locomotion task. Decline walking exposed apparently more abnormal knee frontal and transverse plane adjustments in KA patients than level walking compared with the CG. Hence, walking on sloped surfaces should be included in further motion analysis studies investigating KA patients in order to detect potential deficits that might be not obvious during level walking.
Full-text available
As one of the most universal of all human activities, gait in the able-bodied has received considerable attention, but many aspects still need to be clarified. Symmetry or asymmetry in the actions of the lower extremities during walking and the possible effect of laterality on gait are two prevalent and controversial issues. The purpose of this study was to review the work done over the last few decades in demonstrating: (a) whether or not the lower limbs behave symmetrically during able-bodied gait; and (b) how limb dominance affects the symmetrical or asymmetrical behavior of the lower extremities. The literature reviewed shows that gait symmetry has often been assumed, to simplify data collection and analysis. In contrast, asymmetrical behavior of the lower limbs during able-bodied ambulation was addressed in numerous investigations and was found to reflect natural functional differences between the lower extremities. These functional differences were probably related to the contribution of each limb in carrying out the tasks of propulsion and control during able-bodied walking. In current debates on gait symmetry in able-bodied subjects, laterality has been cited as an explanation for the existence of functional differences between the lower extremities, although a number of studies do not support the hypothesis of a relationship between gait symmetry and laterality. Further investigation is needed to demonstrate functional gait asymmetry and its relationship to laterality, taking into consideration the biomechanical aspects of gait.
It has been shown that gait parameters vary systematically with the slope of the surface when walking uphill (UH) or downhill (DH) ( Andriacchi et al., 1977; Crowe et al., 1996; Kawamura et al., 1991; Kirtley et al., 1985; McIntosh et al., 2006; Sun et al., 1996 ). However, gait trials performed on inclined surfaces have been subject to certain technical limitations including using fixed speed treadmills (TMs) or, alternatively, sampling only a few gait cycles on inclined ramps. Further, prior work has not analyzed upper body kinematics. This study aims to investigate effects of slope on gait parameters using a self-paced TM (SPTM) which facilitates more natural walking, including measuring upper body kinematics and gait coordination parameters. Gait of 11 young healthy participants was sampled during walking in steady state speed. Measurements were made at slopes of +10°, 0° and -10°. Force plates and a motion capture system were used to reconstruct twenty spatiotemporal gait parameters. For validation, previously described parameters were compared with the literature, and novel parameters measuring upper body kinematics and bilateral gait coordination were also analyzed. Results showed that most lower and upper body gait parameters were affected by walking slope angle. Specifically, UH walking had a higher impact on gait kinematics than DH walking. However, gait coordination parameters were not affected by walking slope, suggesting that gait asymmetry, left-right coordination and gait variability are robust characteristics of walking. The findings of the study are discussed in reference to a potential combined effect of slope and gait speed. Follow-up studies are needed to explore the relative effects of each of these factors.
This study investigated the biomechanics of human gait while descending ramps. Fifteen young, healthy subjects (20–30 years) walked self-paced down an instrumented ramp while ground reaction forces (GRF) and sagittal plane body movements were recorded. Ramp angles were set at 0, 5, 10, 15, and 20 degrees. Joint angles for the ankle, knee and hip were found to be most affected by ramp angle during the second half of stance. The primary change in kinematics occurred at the knee while lowering the body to the next step down the ramp. Step length and period decreased as ramp angle increased; however, gait speed did not significantly change. Shear GRFs were found to increase with ramp angle. Calculated sagittal plane joint moments at the knee, and to a lesser extent the ankle and hip, were affected by ramp angle. Knee extension moments showed large increases with increased ramp angle. An increasing dorsiflexion moment of the ankle with increasing ramp angle was found during the first 20% of stance phase. These results suggest that young, healthy individuals maintain relatively constant gait kinematics, particularly during the first half of stance phase, while descending ramps. This requires significant increases in the moment at the knee as ramp angle is increased.
The initiation of gait was studied utilizing electromyography, force-plate data, measurements of walking velocities, and ranges of motion of joints, all of which demonstrated that gait is initiated by the body becoming unbalanced in such a way as to permit a subject to pick one foot the ground in order to take the first step. The subsequent transition of the body to the steady gait pattern occurs rapidly over a period of appproximately three steps. This transition involves rapid changes in the measured forces and activities of the muscles of the lower extremity and the motion of the joints reflects these changes.
Determination was made of step length, stride width, time factors and deviation in the center of pressure during up- and downslope walking in 17 healthy men between the ages of 19 and 34 using a force plate. Slope inclinations were set at 3, 6, 9 and 12 degrees. At 12 degrees, walking speed, the product of step length and cadence, decreased significantly (p less than 0.01) in both up- and downslope walking. The most conspicuous phenomenon in upslope walking was in cadence. The steeper the slope, the smaller was the cadence. The most conspicuous phenomenon in downslope walking was in step length. The steeper the slope, the shorter was the step length.
The aim of this research was to study when and how the stationary process of gait begins when walking starts from upright posture. The subject initially stood up on a large force plate, then walked. Three conditions of speed (slow, normal, fast) were examined. Five subjects participated in the experiment. A total of 105 trials were performed. The results show that, at the end of the first step, the progression velocity of the center of gravity is not significantly different from the mean progression velocity of gait during the second step of gait and that the time necessary to reach steady state gait from initial posture phase is constant. Furthermore, the frequency of the first step, when compared to published values of the steady state gait frequency, is not significantly different from these frequencies. It can be concluded that the aim of the gait initiation process is to place the subject in steady-state gait within the first step, in an invariant time which is dependent only on the body segment parameters of each subject.
The analysis of gait initiation (the transient state between standing and walking) is an important diagnostic tool in the study of pathologic gait and the evaluation of prosthetic devices. Therefore it is important to know the step duration of gait initiation. However, there is little agreement in the literature regarding this step duration, since each author has based their conclusion on a different biomechanical parameter. In this study, gait initiation in seven normal subjects was studied using a mechanical energy analysis. The number of steps necessary to reach steady state was determined based on the fact that in steady-state gait, the net mechanical work of the body over one stride is zero (Winter et al. J. Biomechanics 9, 253-257, 1976). The variance of the work for a stride during steady-state walking was calculated for 100 steady-state trials from a separate database of normal subjects. The stride work was normalized to the subject's body weight (BW) and leg length (LL), and 95% confidence limits were defined from this data at -1.68%BW * LL < epsilon < 1.28%BW * LL. Total body energy during gait initiation was then computed for the seven test subjects. The energy analysis of gait initiation showed that steady state was attained by the end of three full steps. Therefore, a researcher studying gait initiation must allow his/her subject to take three full steps when recording data to ensure that the full event is included.
Kinematic and kinetic data were collected from 12 healthy subjects whilst they performed both downhill and level walking at a controlled cadence. A ramp of 6 m length and a gradient of -19% was used for downhill walking and this incorporated the same force platform that was used for level walking. Planar net joint moments and mechanical power at the ankle, knee, and hip joints were calculated for the sagittal view using force platform and video records based on standard inverse dynamics procedures. On the basis of differences in ankle, knee, and hip joint kinematics the ankle joint was seen to compensate for the gradient at push off and during the swing, the knee joint from early stance through until early swing phase, and the hip joint from early swing through until the early stance phase. The major differences in joint moments and muscle mechanical power were seen in the knee and ankle joint. Whereas peak moments and muscle power were much higher for downhill walking in the knee joint, these measures were significantly smaller at the ankle joint. Hip joint moments and muscle power estimates were only slightly larger for downhill walking. These data explain well the problems that patients with patellofemoral pathology and anterior cruciate ligament (ACL) deficiency encounter with downhill walking, and the muscle soreness experienced by mountain trekkers. RELEVANCE: Biomechanical estimates of musculoskeletal loadings in gait are invariably derived from laboratory studies of walking over a level surface. In this study comparisons were made between downhill and level walking in order to appreciate more fully the increased loadings on the lower extremity under more stressful but not atypical conditions. The data so derived provide the necessary basis for the prediction of loadings on specific muscle/joint structures and can serve as a foundation for exercise prescription with patients recovering from injury or orthopaedic surgery.