Kinematic patterns of participants with a below-knee prosthesis stepping over obstacles of various heights during locomotion

doi:10.1016/S0966-6362(97)01120-X

Gait & Posture

Volume 6, Issue 3, December 1997, Pages 186-192

https://doi.org/10.1016/S0966-6362(97)01120-X Get rights and content

Abstract

The focus of this paper was to examine the lead limb preference and the kinematic patterns of the lead limb of participants with a unilateral below-knee prosthesis when stepping over obstacles of different heights. Firstly, ten unilateral below-knee amputees stepped over obstacles of three different heights placed in their walking path to determine if they had a lead limb preference. Five of the ten participants demonstrated a sound limb lead preference, two participants showed a prosthetic limb lead preference and three showed no preference at all. Seven of these participants subsequently stepped over obstacles of six different heights leading with their sound or prosthetic limb as observed in the first experiment, while whole body kinematic data were collected. Relative joint angles of the stance and swing limb were calculated when the swing limb was over the obstacle. Swing hip elevation and hip and knee flexion increased as functions of obstacle height. Stance limb hip flexion, knee flexion and (on the sound side) ankle plantarflexion increased slightly with increasing obstacle height, but stance limb hip elevation did not. Therefore, it appears that these stance limb modulations served to position the pelvis further back from the obstacle as obstacle height increased. The posterior shell of the prosthetic socket limited residual limb swing knee flexion, and the increased ankle dorsiflexion seen on the lead sound side was not present on the lead prosthetic side. These limitations were associated with increased swing prosthetic foot angle and increased stance ankle plantarflexion. These results provide insights into the adaptability of the locomotor system, and have implications for lower extremity prosthetic design and amputee rehabilitation.

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Cited by (27)

Sensorimotor function and standing balance in older adults with transtibial limb loss
2023, Clinical Biomechanics
Limited research has focused on older prosthesis users despite the expected compounded effects of age and amputation on sensorimotor function, balance, and falls. This study compared sensorimotor factors and standing balance between older individuals with and without transtibial amputation, hypothesizing that prosthesis users would demonstrate worse sensorimotor function. Secondarily we assessed the relationship between standing balance and somatosensation in prosthesis users.
Thirteen persons with unilateral transtibial amputation (71.7 years) and 10 able-bodied controls (71.7 years) participated in this cross-sectional observational study. Passive joint range-of-motion, muscle strength, proprioception (joint position sense), tactile sensitivity, and standing balance (center-of-pressure sway) were compared between groups. A multiple linear regression analysis assessed the relationship between proprioception and balance (without vision) in prosthesis users.
Our hypotheses were generally not supported, with the only differences being reduced joint range-of-motion and strength in prosthesis users (with large effect sizes), but comparable sensation and balance. Notably, prosthesis users demonstrated better proprioception than controls as reflected through better joint position sense when the limb was non-weight bearing. Worse amputated limb proprioception was associated with better standing balance in prosthesis users.
Older prosthesis users have impaired passive joint motion and muscle strength compared to controls that could challenge their ability to position and control the amputated limb to avoid falls during daily activities. However, their better amputated limb proprioception might help counteract those limitations by leveraging sensory feedback from the suspended limb. The relationship between amputated limb proprioception and standing balance suggests a nuanced relationship that warrants further study.
Restricting ankle motion via orthotic bracing reduces toe clearance when walking over obstacles
2016, Gait and Posture
When trans-tibial amputees cross obstacles leading with their prosthesis, foot clearance is achieved using compensatory swing-phase kinematics. Such compensation would suggest able-bodied individuals normally use swing-phase ankle dorsiflexion to attain adequate obstacle clearance; however, direct evidence of such contribution is equivocal. This study determined the contribution of sagittal plane ankle motion in achieving lead-limb clearance during obstacle negotiation.
Twelve male able-bodied individuals (ages 18–30) completed obstacle crossing trials while walking on a flat surface. Lead-limb (right) ankle motion was manipulated using a knee-ankle-foot orthosis. Trials were completed with the ankle restricted at a neutral angle or unrestricted (allowing ∼±15° plantar/dorsiflexion).
Restricted ankle motion caused significant increase in trail-limb foot placement distance before the obstacle (p = 0.005); significant decrease in vertical toe clearance (p < 0.003), vertical heel clearance (p = 0.045), and lead-limb foot placement distance after the obstacle (p = 0.045); but no significant changes in knee angle at instant of crossing or in average walking speed.
The shifts in foot placements altered the part of swing that the lead-limb was in when the foot crossed the obstacle, which led to a decrease in clearance. These adaptations may have been due to being unable to dorsiflex the ankle to ‘lift’ the toes in mid-swing or to plantarflex the ankle during initial contact following crossing, which changed how the lead-limb was to be loaded. These findings suggest individuals using ankle bracing or those with ankle arthrodesis, will have reduced gait safety when negotiating obstacles.
The effects of laterality on obstacle crossing performance in unilateral trans-tibial amputees
2015, Clinical Biomechanics
Citation Excerpt :
Depending on a particular physical therapist's or prosthetist's opinion, leading with either the prosthetic or intact limb can be advocated during amputee rehabilitation, as both approaches can be justified using evidence from published research. For instance, an intact limb lead could be advocated because, when leading with the prosthetic limb, UTAs are unable to increase toe clearance by dorsiflexing the foot during swing (Hill et al., 1997), have knee flexion limited by the posterior edge of the socket (Hill et al., 1997) and are mechanically constrained by the need to minimise residual knee loading during the initial landing period following crossing (Buckley et al., 2013). Conversely, leading with the prosthetic limb may be advocated because the lack of active ‘ankle’ control and power generation at the prosthetic (support) limb (Barnett et al.) means that intact (swing) limb toe clearance is reduced in comparison to that in the able-bodied.
Unilateral trans-tibial amputees have bilaterally reduced toe clearance, and an increased risk of foot contact, while crossing obstacles compared to the able-bodied. While the able-bodied tend to lead with a ‘preferred’ limb it is equivocal whether amputees prefer to lead with the intact or prosthetic limb. This study determined the effects of laterality, compared to side of amputation, on amputees' obstacle crossing performance. To help understand why laterality could affect performance we also assessed knee proprioception for both limbs.
Foot placement and toe clearance parameters were recorded while nine amputees crossed obstacles of varying heights leading with both their intact and prosthetic limbs. Joint-position sense was also assessed. Participants self-reported which limb was their preferred (dominant) limb.
There were no significant differences in foot placements or toe clearance variability across lead-limb conditions. There were no significant differences in toe clearance between intact and prosthetic lead-limbs (p = 0.28) but toe clearance was significantly higher when amputees led with their preferred compared to non-preferred limb (p = 0.025). There was no difference in joint-position sense between the intact and residual knees (p = 0.34) but joint-position sense tended to be more accurate for the preferred, compared to non-preferred limb (p = 0.08).
Findings suggest that, despite the mechanical constraints imposed by use of a prosthesis, laterality may be as important in lower-limb amputees as it is in the able bodied. This suggests that amputees should be encouraged to cross obstacles leading with their preferred limb.
Principles of obstacle avoidance with a transfemoral prosthetic limb
2012, Medical Engineering and Physics
Citation Excerpt :
In addition, the stance limb hip flexion, knee flexion and (on the non-affected side) ankle plantarflexion increase slightly with increased obstacle height, but the stance limb hip elevation does not. Hill et al. [11] concluded that modulations of the stance limb served to position the pelvis further back from the obstacle as the height of the obstacle increased. Transfemoral (TF) amputee subjects make use of adjustment strategies to compensate for the loss of muscles and sensory input in their prosthetic limb during obstacle avoidance, and they learn to cope with bilaterally delayed and decreased obstacle avoidance responses in both limbs [13].
In this study, conditions that enable a prosthetic knee flexion strategy in transfemoral amputee subjects during obstacle avoidance were investigated. This study explored the hip torque principle and the static ground principle as object avoidance strategies. A prosthetic limb simulator device was used to study the influence of applied hip torques and static ground friction on the prosthetic foot trajectory. Inverse dynamics were used to calculate the energy produced by the hip joint. A two-dimensional forward dynamics model was used to investigate the relation between obstacle–foot distance and the necessary hip torques utilized during obstacle avoidance. The study showed that a prosthetic knee flexion strategy was facilitated by the use of ground friction and by larger active hip torques. This strategy required more energy produced by the hip compared to a knee extension strategy. We conclude that when an amputee maintains enough distance between the distal tip of the foot and the obstacle during stance, he or she produces sufficiently high, yet feasible, hip torques and uses static ground friction, the amputee satisfies the conditions for enable stepping over an obstacle using a knee flexion strategy.
Differences in the coordination of agonist and antagonist muscle groups in below-knee amputee and able-bodied children during dynamic exercise
2008, Journal of Electromyography and Kinesiology
Citation Excerpt :
From a kinematics point of view, the results showed that joint excursions were similar between AB (CL) and BKA (AL and NAL) children during SIP. This finding revealed the high consistency in behaviour between subject groups, as reported by Hill et al. (1997, 1999) for obstacle avoidance. Thus, the reorganization of coordination observed between AB and BKA children at the level of joint kinetics could be explained by the location of the line of the reaction force vector ahead or behind the different joint centres during stance.
A lack of co-contraction may predispose to knee instability or laxity, resulting in additional shear stress on the internal structures of the knee, especially in below-knee amputee (BKA) subjects. The purposes of this study were: (1) to provide information on how BKA children regulate agonist and antagonist muscle coordination, and (2) to quantify the level of knee co-contraction in able-bodied (AB) and BKA children during the stepping-in-place (SIP) task. Fourteen children (7 BKA vs. 7 AB), paired for age, weight and height, participated in this study. One-way ANOVA with Newman–Keuls post hoc tests (p < 0.05) were used to compare peak power, the co-contraction index, and the resultant agonist and antagonist moments during different phases of SIP. Statistical analysis revealed that BKA children perform the task with similar kinematics than AB children while they generated less co-contraction in both their non-amputated limb and amputated limb, notably because the two groups of children used different agonist and antagonist muscles during the same periods of the SIP. This lack of co-contraction may reduce knee stability and may stress the internal structures of the knee in both the NAL and AL, and may lead to the development of premature knee osteoarthritis.
Obstacle crossing in lower limb amputees
2007, Gait and Posture
Citation Excerpt :
Due to the absence of ankle dorsiflexors and the stiffness of the prosthetic ankle, amputees are not able to shorten the swing limb by ankle dorsal flexion. In TT a decrease in knee flexion and ankle dorsal flexion of the prosthetic limb in swing was shown in obstacle crossing [14]. So far, no studies have been published concerning obstacle crossing in TF.
To study limitations in function and adjustment strategies in lower limb amputees during obstacle crossing.
Observational cohort study.
Transfemoral and transtibial amputees and able-bodied control subjects.
In a motion analysis laboratory unimpeded and obstacle crossing runs were performed. The subjects stepped over an obstacle of 0.1 m height and thickness and 1 m width. Outcome measures were gait velocity, hip, knee and ankle joint angles and leading limb preference.
Whereas able-bodied and transtibial subjects demonstrated an increase in knee flexion during obstacle crossing compared to unimpeded walking, in transfemoral amputees the opposite was seen, namely a decrease in knee flexion. The lack of knee strategy in transfemoral amputees was compensated by circumduction at the hip on the prosthetic side and plantar flexion of the non-affected ankle. Transtibial amputees preferred to cross the obstacle with the prosthetic limb first, while transfemoral amputees preferred the non-affected limb.
The different leading limb strategy in transfemoral and transtibial amputees could be explained by the restricted flexion and propulsion properties of the prosthetic knee. Training of obstacle crossing tasks during rehabilitation and improvement of prosthetic design may contribute to safe obstacle crossing.

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Kinematic patterns of participants with a below-knee prosthesis stepping over obstacles of various heights during locomotion

Abstract

J Biomech

Gait and Posture

J Biomech

Gait and Posture

Neuroscience

The effect of footwear mass on the gait patterns of unilateral below-knee amputees

Prosth Orth Int

Evaluation of a prosthetic shank with variable inertial properties

Clin Prosth Orthot

Energy expenditure of ambulation in patients with above-knee amputations

Arch Phys Med Rehabil