Level Walking Research Articles

Comparison of biomechanical parameters in lower limb joints of stroke patients according to conventional evaluation scores during level walking.

Objective: Patients with chronic stroke capable of independent gait were classified into functional ambulation category (FAC) 4 or 5, and the kinetic and kinematic data on their lower limb joints on the affected and unaffected sides were compared with that of healthy individuals. Finally, the qualitative changes in the gait of patients with stroke were investigated based on the differences in FAC scores. Methods: Twelve healthy participants and 19 patients with stroke capable of independent gait were included. The three-dimensional (3D) motion analysis and conventional assessment were conducted for all patients with stroke. Results: The FAC 5 group exhibited a larger range of motion (ROM) than the FAC 4 group in knee and hip joints on the affected side and only in the hip on the unaffected side. In the FAC 5 group, ROM differences in the healthy group on either the affected or unaffected side were absent. The peak of the hip flexion moment on the affected side in both the FAC 4 and 5 groups was smaller than that in the healthy group and in the FAC 4 group on the unaffected side. The absorption power minimum on the affected side was smaller only in the FAC 4 group than that in the healthy group and was larger in the FAC 5 group than that in the FAC 4 group. On the unaffected side, the absorption power minimum was smaller only in the FAC 4 group than that in the healthy group. Conclusion: Functional differences in gait were found in patients classified based on conventional evaluation capable of independent gait after post-stroke rehabilitation. Patients may not exhibit complete recovery in the kinetic indices even if they are judged to be normal in the conventional evaluation, and the kinematic gait indices indicate recovery. Evaluating kinetic indices in addition to kinematic indices is necessary, and joint power may be an especially useful index.

Medial Meniscus Posterior Root Tears Lead to Changes in Joint Contact Mechanics at Low Flexion Angles During Simulated Gait

Background: Previous biomechanical studies evaluating medial meniscus posterior root tears (MMPRTs) are limited to low loads applied at specified loading angles, which cannot capture the effects of MMPRTs during the multidirectional forces and moments placed across the knee during physiological activities. Purpose: To quantify the effects of MMPRTs on knee joint contact mechanics during simulated gait. Study Design: Controlled laboratory study. Methods: Six human cadaveric knees were mounted on a robotic simulator programmed to apply dynamic forces, moments, and flexion angles to mimic level walking. Twelve cycles of multidirectional and dynamic standard gait input waveforms, normalized to specimen-specific body weight, were applied to the following conditions: (1) native, intact meniscus and (2) MMPRT. Peak contact stress, contact area, and the position of the weighted center of contact across the medial tibial plateau throughout the stance phase of gait were quantified using an electronic sensor placed across the medial tibial plateau. The difference between the intact state and MMPRT condition was calculated for each metric, and then the means and 95% CIs were computed. Results: Despite heterogeneity in knee contact forces, MMPRTs significantly increased peak contact stress by a mean of 2 MPa across 20% to 37% of the simulated gait cycle and significantly decreased the contact area by a mean of 200 mm2 across 16% to 60% of the simulated gait cycle in comparison with the native state. There was no significant difference in the position of the weighted center of contact, in either the anterior-posterior or medial-lateral directions, after MMPRT. Conclusion: MMPRTs led to both a significant increase in peak contact stress and decreased contact areas for a portion of the simulated gait cycle ranging from 20% to 37% of gait, during which time the femur was flexed <15°. Clinical Relevance: Contact mechanics are significantly affected after MMPRTs during early to midstance and at knee flexion angles lower than demonstrated previously. These data provide further biomechanical justification for treating MMPRTs.

Correlation between Postural Stability and Lower Extremity Joint Reaction Forces in Young Adults during Incline and Decline Walking

Postural stability may be affected during slope walking, as there are different body kinetics and kinematic responses compared with level walking. Understanding body adaptations toward different inclinations is essential to prevent the risk of injury from falls or slips. This study was conducted to determine the correlations between stability parameters and loading response in terms of joint reaction force at the lower-extremity joints during inclined and declined walking. Twenty male subjects walked in the level, incline, and decline directions on a custom-built platform at three different slope angles (i.e., 5°, 7.5°, and 10°). To determine the ground reaction force (GRF), joint reaction force (JRF), center of pressure (COP), and center of mass (COM), a motion capture system was used to read the data of the ten reflective markers and transfer them to visual three-dimensional (3D) software. Pearson’s correlation test was performed with statistical significance set at p &lt; 0.05 to evaluate the correlation of the required coefficient of friction (RCOF), postural stability index (PSI), and COP-COM distance with the JRF. This study has identified that the JRF changes in opposition to the changes in the RCOF during the initial strike during incline and decline walking, as JRF increases, the RCOF decreases with different strengths of correlation. There is also a strong positive correlation between the PSI and JRF in the proximal–distal direction, where the JRFs change in accordance with the change in the PSI, and the JRF increases with the increment of PSI. In addition, the JRF of the lower extremity also changed in a manner similar to the COP-COM distance in the medial–lateral direction. Overall, each stability parameter was correlated with the JRF of the lower-extremity joints in different directions and strengths. This study demonstrated that slope walking is particularly affected by surface inclination in terms of stability and loading. Therefore, this research can serve as a basis for future studies on slopes, as there is no specific basis for a maximum degree of inclination that is safe and suitable for all applications.

Comparison of plugin and redundant marker sets to analyze gait kinematics between different populations

BackgroundGait model consists of a marker set and a segment pose estimation algorithm. Plugin marker set and inverse kinematic algorithm (IK.) are prevalent in gait analysis, especially musculoskeletal motion analysis. Adding extra markers for the plugin marker set could increase the robustness to marker misplacement, motion artifacts, and even markers occlusion. However, how the different marker sets affect the gait analysis's kinematic output is unclear. Therefore, this study aims to investigate the effect of marker sets on the kinematic output during level walking in different populations.ResultsIn all three planes, there are significant differences (P < 0.05) between marker sets in some kinematic variables at the hip, knee, and ankle. In different populations, the kinematic variables that show significant differences varied. When comparing the kinematic differences between populations using the two marker sets separately, the range of motion (ROM) of hip flexion was only found to be a significant difference using the redundant marker set, while the peak internal rotation at the knee was only found a significant difference using plugin marker set. In addition, the redundant marker set shows less intra-subject variation than the plugin marker set.ConclusionThe findings in this study demonstrate the importance of marker set selection since it could change the result when comparing the kinematic differences between populations. Therefore, it is essential to increase the caution in explaining the result when using different marker sets. It is crucial to use the same marker set, and the redundant marker set might be a better choice for gait analysis.

Exploring the Impact of Passive Ankle Exoskeletons on Lower-Limb Neuromechanics during Walking on Sloped Surfaces: Implications for Device Design

Humans and animals navigate complex and variable terrain in day-to-day life. Wearable assistive exoskeletons interact with biological tissues to augment movement. Yet, our understanding of how these devices impact the biomechanics of movement beyond steady-state environments remains limited. We investigated how passive ankle exoskeletons influence mechanical energetics and neuromuscular control of the lower-limb during level, incline, and decline walking. We collected kinematic and kinetic measures to determine ankle, knee, and hip mechanics and surface electromyography to characterize muscle activation of lower-limb muscles while participants walked on level, incline, and decline surfaces (0°, +5°, and −5°) with exoskeletons of varying stiffnesses (0–280 Nm rad−1). Our results demonstrate that walking on incline surfaces with ankle exoskeletons was associated with increased negative work and power at the knee and increased positive work and power at the hip. These alterations in joint energetics may be linked to an additional requirement to load the springy exoskeleton in incline conditions. Decline walking with ankle exoskeletons had no influence on knee or hip energetics, likely owing to disrupted exoskeleton clutch actuation. To effectively offload the musculoskeletal system during walking on sloped surfaces, alterations to passive ankle exoskeleton clutch design are necessary.

A Study to Assess the Effectiveness of Diaphragmatic Breathing on selected Physiological Parameters of COPD patients in selected hospitals

Background: The respiratory system consists of air passage and lungs the part of respiratory system nose parents’ clearance procedure bronchi alveoli and lungs. It is help to gas exchange in human being respiratory diseases are more responsible for human morbidity and motility. The various disease occurs in human related to respiratory. i.e. asthma pneumonia bronchitis emphysema pleural effusion COPD. Method: The research design used for this study is pre-experimental design. The study was conducted on COPD patients of selected hospitals. Target population of present study was population of COPD patients admitted in selected hospitals. The 30 samples were selected by non-probability convenient sampling technique. Result: In present study majority of (46.67) of patient too breathless to leave the bed similar study conducted by kadam v. Also observed that 23.3% of the COPD patients got short of breath when hurrying on level ground or walking up a staircase, 40% of them walk slower than people of the same age because of breathlessness and 36.7% of them had to stop for breath when doing any activity at their own pace. Conclusion: The findings suggest that an effective diaphragmatic breathing on selected physiological parameters of COPD.

Human-in-the-Loop Adaptive Control of a Soft Exo-Suit With Actuator Dynamics and Ankle Impedance Adaptation.

Soft exo-suit could facilitate walking assistance activities (such as level walking, upslope, and downslope) for unimpaired individuals. In this article, a novel human-in-the-loop adaptive control scheme is presented for a soft exo-suit, which provides ankle plantarflexion assistance with unknown human-exosuit dynamic model parameters. First, the human-exosuit coupled dynamic model is formulated to express the mathematical relationship between the exo-suit actuation system and the human ankle joint. Then, a gait detection approach, including plantarflexion assistance timing and planning, is proposed. Inspired by the control strategy that is used by the human central nervous system (CNS) to handle interaction tasks, a human-in-the-loop adaptive controller is proposed to adapt the unknown exo-suit actuator dynamics and human ankle impedance. The proposed controller can emulate human CNS behaviors which adapt feedforward force and environment impedance in interaction tasks. The resulting adaptation of actuator dynamics and ankle impedance is demonstrated with five unimpaired subjects and implemented on a developed soft exo-suit. The human-like adaptivity is performed by the exo-suit in several human walking speeds and illustrates the promising potential of the novel controller.

Trunk orthosis with joints providing resistive force improves dynamic sagittal alignment in postoperative patients with lumbar spinal stenosis

This study aimed to determine whether a trunk orthosis with joints providing resistive force (TORF) modifies sagittal malalignment during level walking in patients with lumbar spinal stenosis (LSS). Fifteen patients, 6 months after undergoing surgery for LSS, performed level walking at a self-selected speed while wearing a TORF. Dynamic sagittal alignment, including sagittal vertical axis, lumbar lordosis, and pelvic tilt, and spatiotemporal data as well as lower limb kinematic and kinetic data were recorded using a three-dimensional motion analysis system and six force plates. Statistical analysis was performed to compare these data with and without the TORF, respectively. Compared to the condition without the TORF, the use of the TORF significantly decreased positive sagittal vertical axis (p < 0.05) and increased the lumbar lordosis and pelvic tilt (p < 0.05). Peak hip flexion angle and extension moment during loading response (LR) significantly increased (p < 0.05), and peak hip extension angle and flexion moment during PS statistically decreased (p < 0.05). There was no difference in spatiotemporal data between the two conditions. Our findings suggest that TORF may modify the dynamic sagittal global alignment and lower limb kinematic and kinetics in postoperative LSS patients during level walking.

The topographical attenuation of cutaneous input is modulated at the ankle joint during gait.

The attenuation of sensory inputs via various methods has been demonstrated to impair balance control and alter locomotor behavior during human walking; however, the effects of attenuating foot sole sensation under distinct areas of the foot sole on lower extremity motor output remains poorly understood. Thus, the purpose of this study was to attenuate cutaneous feedback via regional hypothermia under five different areas of the foot sole and investigate the resultant modulation of kinematic and muscle activity during level walking. Electromyography from eight lower leg muscles, kinematics, and location of center of pressure was recorded from 48 healthy young adults completing walking trials with normal and reduced cutaneous sensation from bilateral foot soles. The results of this study highlight the modulatory response of the tibialis anterior in terminal stance (propulsion and toe-off) and medial gastrocnemius muscle throughout the entire stance phase of gait. The topographical organization of foot sole skin in response to the attenuation of cutaneous feedback from different areas of the foot sole significantly modified locomotor activity. Furthermore, the locomotor response to cutaneous attenuation under the same regions that we previously facilitated with tactile feedback do not oppose each other, suggesting different physiological changes to foot sole skin generate unique gait behaviors.

GAIT CHARACTERISTICS OF PATIENTS WITH SYMPTOMATIC CARTILAGE DEFECTS OF THE KNEE

AbstractObjectivesLittle is known about the impact of cartilage defects on knee joint biomechanics. This investigation aimed to determine the gait characteristics of patients with symptomatic articular cartilage lesions of the knee.MethodsGait analyses were performed at the Regional North-West Joint Preservation Centre. Anthropometric measurements were obtained, then 16 retroreflective markers representing the Plug-in-Gait biomechanical model were placed on pre-defined anatomical landmarks. Participants walked for two minutes at a self-selected speed on a treadmill on a level surface, then for 2 minutes downhill. A 15-camera motion-capture system recorded the data. Knee kinematics were exported into Matlab to calculate the average kinematics and spatiotemporal parameters per patient across 20 gait cycles. Depending on the normality of the data, paired t-tests or Wilcoxon ranked tests were performed to compare both knees (α = 0.05).Results20 patients participated; one of whom has bilateral cartilage defects. All 20 data sets were analysed for level walking; 18 were analysed for downhill walking. On a level surface, patients walked at an average speed of 3.1±0.8km/h with a cadence of 65.5±15.3 steps/minute. Patients also exhibited equal step lengths (0.470±0.072m vs 0.471±0.070m: p=0.806). Downhill, the average walking speed was 2.85±0.5km/h with a cadence of 78.8±23.1 steps/minute and step lengths were comparable (0.416±0.09m vs 0.420±0.079m: p=0.498). During level walking, maximum flexion achieved during swing did not differ between knees (54.3±8.6° vs 55.5±11.0°:p=0.549). Neither did maximal extension achieved at heel strike (3.1±5.7° vs 5.4±4.7°:p=0.135). On average, both knees remained in adduction throughout the gait cycle, with the degree of adduction greater in flexion in the operative knee. However, differences in maximal adduction were not significant (22.4±12.4° vs 18.7±11.0°:p=0.307). Maximal internal-external rotation patterns were comparable in stance (0.9±7.7° vs 3.5±9.8°: p=0.322) and swing (7.7±10.9° vs 9.8±8.3°:p=0.384). During downhill walking, maximum flexion also did not differ between operative and contralateral knees (55.38±10.6° vs 55.12±11.5°:p=0.862), nor did maximum extension at heel strike (1.32±6.5° vs 2.73±4.5°:p=0.292). No significant difference was found between maximum adduction of both knees (15.87±11.0° vs 16.78±12.0°:p=0.767). In stance, differences in maximum internal-external rotation between knees were not significant (5.39±10.7° vs 6.10±11.8°:p=0.836), nor were they significant in swing (7.69±13.3° vs 7.54±8.81°:p=0.963).ConclusionsKnee kinematics during level and downhill walking were symmetrical in patients with a cartilage defect of the knee, but an increased adduction during flexion in the operative knee may lead to pathological loading across the medial compartment of the knee during high flexion activities. Future work will investigate this further and compare the data to a healthy young population. We will also objectively assess the functional outcome of this joint preservation surgery to monitor its success.Declaration of Interest(b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Instrumental Gait Analysis and Tibial Plateau Modelling to Support Pre- and Post-Operative Evaluations in Personalized High Tibial Osteotomy

High tibial osteotomy (HTO) is intended to treat medial knee osteoarthritis by realigning the joint such that the loading in the knee during functional activity shifts laterally. The aim of this study was to use a novel methodology combining motion analysis and 3D modelling to assess the efficacy of this surgery in changing the loading location in the knee in a cohort of 25 patients treated with personalized HTO. Pre-operatively and at 6 months post-surgery, weight-bearing CT and gait analysis during level walking were performed on all patients, as well as clinical evaluations using KOOS and VAS scores. CT scans were used to generate a knee bone model and a virtual tibial plateau plane; the intersection pattern between this plane and the ground reaction force (GRF) vector was calculated in the pre- and post-operative gait analyses. Clinical scores improved significantly (p &lt; 0.001) after surgery (pre-/post-operative KOOS and VAS: 56.2 ± 14.0/82.0 ± 8.3 and 6.3 ± 1.7/1.5 ± 1.7). Post-operative GRF-to-tibial plateau intersection patterns were significantly (p &lt; 0.001) more lateral (31.9 ± 19.8% of tibial plateau width) than the pre-operative patterns. Personalized HTO successfully and consistently lateralizes the GRF at the knee, in association with significant improvements in function and pain. The novel combination of 3D bone modelling and motion analysis also has the potential to further aid HTO surgical planning.

Joint power, joint work and lower limb muscle activity for transitions between level walking and stair ambulation at three inclinations

To enhance human mobility, training interventions and assistive lower limb wearable robotic designs must draw insights from movement tasks from daily life. This study aimed to analyze joint peak power, limb and joint work, and muscle activity of the lower limb during a series of stair ambulation conditions. We recruited 12 subjects (25.4±4.5 yrs, 180.1±4.6 cm, 74.6±7.9 kg) and studied steady gait and gait transitions between level walking, stair ascent and stair descent for three staircase inclinations (low 19°, normal 30.4°, high 39.6°). Our analysis revealed that joint peak power, limb and joint work, and muscle activity increased significantly compared to level walking and with increasing stair inclination for most of the conditions analyzed. Transition strides had no increased requirements compared to the maxima found for steady level walking and steady stair ambulation. Stair ascent required increased lower limb joint positive peak power and work, while stair descent required increased lower limb joint negative peak power and work compared to level walking. The most challenging condition was high stair inclination, which required approximately thirteen times the total lower limb joint positive and negative net work during ascent and descent, respectively. These findings suggest that training interventions and lower limb wearable robotic designs must consider the major increases in lower limb joint and muscle effort during stair ambulation, with specific attention to the demands of ascent and descent, to effectively improve human mobility.

Abnormal gait pattern in downhill hiking is related to muscular deficits of the knee flexors and extensors in active patients with total knee arthroplasty

BackgroundTo assess the in-field walking mechanics during downhill hiking of patients with total knee arthroplasty five to 14 months after surgery and an age-matched healthy control group and relate them to the knee flexor and extensor muscle strength. MethodsParticipants walked on a predetermined hiking trail at a self-selected, comfortable pace wearing an inertial sensor system for recording the whole-body 3D kinematics. Sagittal plane hip, knee, and ankle joint angles were evaluated over the gait cycle at level walking and two different negative slopes. The concentric and eccentric lower extremity muscle strength of the knee flexors and extensors isokinetically at 50 and 120°/s were measured. FindingsLess knee flexion angles during stance have been measured in patients in the operated limb compared to healthy controls in all conditions (level walking, moderate downhill, steep downhill). The differences increased with steepness. Muscle strength was lower in patients for both muscle groups and all measured conditions. The functional hamstrings to quadriceps ratio at 120°/sec correlated with knee angle during level and downhill walking at the moderate slope in patients, showing higher ratios with lower peak knee flexion angles. InterpretationThe study shows that even if rehabilitation has been completed successfully and complication-free, five to 14 months after surgery, the muscular condition was still insufficient to display a normal gait pattern during downhill hiking. The muscle balance between quadriceps and hamstring muscles seems related to the persistence of a stiff knee gait pattern after knee arthroplasty. LoE: III.

The effects of a sleeve knee brace during stair negotiation in patients with symptomatic patellofemoral osteoarthritis

BackgroundThe patellofemoral joint is an important source of pain in knee osteoarthritis. Most biomechanical research in knee osteoarthritis has focused on the tibiofemoral joint during level walking. It is unknown what happens during stair negotiation in patients with patellofemoral joint osteoarthritis, a task commonly increasing pain. Conservative therapy for patellofemoral joint osteoarthritis includes the use of a sleeve knee brace. We aimed to examine the effect of a sleeve knee brace on knee biomechanics during stair negotiation in patellofemoral joint osteoarthritis patients. Methods30 patellofemoral joint osteoarthritis patients (40–70 years) ascended and descended an instrumented staircase with force plates under two conditions – wearing a Lycra flexible knee support (Bioskin Patellar Tracking Q Brace) and no brace (control condition). Knee joint kinematics (VICON) and kinetics were recorded. FindingsDuring stair ascent, at the knee, the brace significantly reduced the maximal flexion angle (2.70, P = 0.002), maximal adduction angle (2.00, P = 0.044), total sagittal range of motion (2.00, P = 0.008), total frontal range of motion (1.70, P = 0.023) and sagittal peak extension moment (0.05 Nm/kg, P = 0.043) compared to control. During stair descent, at the knee, the brace significantly reduced the maximal flexion angle (1.80, P = 0.039) and total sagittal range of motion (1.50, P = 0.045) compared to control. InterpretationThe small changes in knee joint biomechanics during stair negotiation observed in our study need to be investigated further to help explain mechanisms behind the potential benefits of a sleeve knee brace for painful patellofemoral joint osteoarthritis.

Interaction between functional capability and sleep quality at midterm after total knee arthroplasty: a Japanese retrospective cohort study

No report has clarified the frequency and interacting factors affecting sleep disturbance among Asian patients at midterm after total knee arthroplasty (TKA). This study aimed to evaluate the frequency of sleep disturbance at midterm after TKA in a Japanese cohort and to identify intervening factors for sleep. We hypothesized that residual knee pain and decreased functional capability negatively interact with sleep quality after TKA. A total of 209 Japanese participants (average age: 77.1 ± 8.3 years; postoperative follow-up period: 4.5 ± 1.9 years) who underwent primary TKA for knee osteoarthritis were included in this study. Sleep quality, satisfaction, pain, functional capability, joint awareness, and mental condition were evaluated using the Pittsburgh Sleep Quality Index (PSQI), Knee Society Score (KSS) 2011, Forgotten Joint Score (FJS)-12, and 12-Item Short-Form Health Survey (SF-12) Mental Component Summary (MCS). Multivariable analysis was performed to determine the influencing factors on PSQI. The scores for the PSQI, satisfaction with pain level while lying in bed, pain during level walking, functional activity category in the KSS 2011, awareness of the artificial joint in bed at night in the FJS-12, and SF-12 MCS were 6.7 ± 3.0, 5.8 ± 1.8, 1.6 ± 2.3, 62 ± 22, 1.5 ± 1.4, and 56 ± 9.3 on average, respectively. Sleep disturbance (PSQI ≥ 5.5) occurred in 54% of the Japanese participants. Multivariable analysis revealed that high functional capability was a significant factor associated with sleep quality improvement (p < 0.05). Decreased functional capability, not residual knee pain, negatively interacted with sleep quality. The sleep disturbance rate was high during the middle postoperative period after TKA in the Japanese cohort.

Knee kinematics are primarily determined by implant alignment but knee kinetics are mainly influenced by muscle coordination strategy

Implant malalignment has been reported to be a primary reason for revision total knee arthroplasty (TKA). In addition, altered muscle coordination patterns are commonly observed in TKA patients, which is thought to alter knee contact loads. A comprehensive understanding of the influence of surgical implantation and muscle recruitment strategies on joint contact mechanics is crucial to improve surgical techniques, increase implant longevity, and inform rehabilitation protocols. In this study, a detailed musculoskeletal model with a 12 degrees of freedom knee was developed to represent a TKA subject from the CAMS-Knee datasets. Using motion capture and ground reaction force data, a level walking cycle was simulated and the joint movement and loading patterns were estimated using a novel technique for concurrent optimization of muscle activations and joint kinematics. In addition, over 12′000 Monte Carlo simulations were performed to predict knee contact mechanics during walking, considering numerous combinations of implant alignment and muscle activation scenarios. Validation of our baseline simulation showed good agreement between the model kinematics and loading patterns against the in vivo data. Our analyses reveal a considerable impact of implant alignment on the joint kinematics, while variation in muscle activation strategies mainly affects knee contact loading. Moreover, our results indicate that high knee compressive forces do not necessarily originate from extreme kinematics and vice versa. This study provides an improved understanding of the complex inter-relationships between loading and movement patterns resulting from different surgical implantation and muscle coordination strategies and presents a validated framework towards population-based modelling in TKA.

Normative Data of the External Work of Individual Limbs and of the Distribution of Joint Work During Stair Crossing

BackgroundStair walking requires to elevate or lower the body center of mass and results in increased muscle contractions and consumed energy compared to level walking. Mechanical work produced by the body can be quantified through Individual Limb Method and the summed lower limb joint work but there does not exist normative data of these works in stair ascent and descent compared to slope ascent and descent of the same individuals. MethodsUpstair and downstair walking were investigated at 0%, 5% and 12% inclinations and compared to upslope and downslope walking for thirteen able-bodied volunteers. Lower limb joint and individual limb powers and works were compared across walking conditions. FindingsWork production and absorption required to elevate or lower the center of mass directly depend on the inclination to be crossed (about 0.35 J/kg for 5% slope, 0.9 J/kg for 12% slope and 1.6 J/kg for stair). However, the distribution among joints and between gait phases is different when considering stair versus slope walking. In particular, the role of the knee is exacerbated for work production in stair ascent (45% of total work) as well as for work absorption in stair descent (61% of total work). Also, more work production/absorption is performed during the swing phase for stair walking then for slope walking. InterpretationThis study provides reference data of the Individual Limb mechanical work performed during stair walking and show that this method can substitute to summed lower limb joint one during the stance phase of stair walking.

Motion Analysis of a Frontal Plane Adaptable Prosthetic Foot.

ABSTRACT Introduction An objective of designing a prosthetic foot is to achieve the natural adaptability of the foot and ankle on various surfaces and different forms of gait. Frontal plane position of the foot relative to the shank changes with many functional aspects of gait, such as turning, stairs, and walking on uneven ground. Prosthetic foot designs have variable frontal plane adaptability. An investigation foot with a linkage with ±10° of frontal plane motion was developed to improve frontal plane response under various conditions. The purpose of this study was to compare the kinematics of locked and unlocked conditions of a frontal plane adaptable prosthetic foot and the person’s usual foot while walking forward on a level surface, on an unstable rock surface, and sidestep, using a crossover design. These different conditions result in changes in frontal plane motion in the anatomical foot and ankle, and the current study evaluates whether there are similar trends in prosthetic feet. Materials and Methods People were included if they had a unilateral below-knee amputation, intact residual limb skin, were over 16 years old, and were able to walk more than 400 m on level ground without using a walking aid and without an increase in pain. The control group was people without amputations who completed the procedures once. Participants with amputations completed forward walking on level ground, on an unstable rock surface, and sidestep with their usual foot. Then after 2 weeks of accommodation, participants repeated these tests with the investigational foot unlocked and locked. Motion analysis data were collected with a 12-camera optically based system. Primary outcomes were sagittal and frontal plane motions of the foot relative to the shank. In addition, step length, step width, and stride velocity were obtained from the kinematic measures. Paired t-tests were used for statistical inference for individual participant comparisons. Unpaired t-tests were used for comparisons between the controls and people with amputations. Results Twenty-one people with amputations and 10 controls completed the tests. Participants with amputation had 16 different usual feet. There was a wide variation in usual foot motion during forward walking, whereas investigational foot conditions showed less variability. During level walking, control subjects had more frontal plane motion than any of the foot conditions, and the unlocked had more frontal plane motion than the usual foot and locked condition. Walking across an unstable rock surface showed similar trends, with control participants having more sagittal and frontal plane ankle motion compared with any prosthetic foot condition. Also, the unlocked had statistically greater frontal plane motion than the usual foot or locked condition. Sidestep results were also consistent with other gait tests. The control participants’ sagittal plane ankle range of motion was significantly more than the prosthetic sagittal plane motion for all foot conditions, whether the prosthetic side was leading or trailing. There was significantly more frontal plane motion with the unlocked than the usual foot and locked condition when the prosthetic foot was trailing or leading. Discussion and Conclusions Wide variation in usual foot range of motions in the frontal and sagittal planes confirmed the need for additional controls when considering the effect of the linkage alone. The unlocked had increased frontal plane ranges of motion compared with the locked and the majority of usual foot for all gait conditions, including level walking. This finding demonstrated that people with amputations were functionally using the additional range of motion provided by the linkage. However, control subjects used more range of motion in both the sagittal and frontal planes for the unstable rock surface and sidestepping. Increased frontal plane range of motion did not translate into improved stride length and velocity, step width, or center of mass deviations. Clinical Relevance The person-specific functional activities should be considered when choosing a prosthetic foot. A prosthesis with frontal plane motion may be applicable for a person who moves in a sidestep pattern or on uneven ground.

Effects of Wearing Slippers While Obstacle Crossing in Healthy Young Adults: Strategy for Toe Clearance Enhancement and Prevention of Slipper Loss.

Wearing loose footwear, such as slippers, poses a risk factor for tripping. Previous studies have examined obstacle crossing to find strategies to avoid tripping. However, the effect of wearing slippers on the likelihood of tripping remains unclear. Therefore, this study aimed to determine whether wearing slippers while level walking and obstacle crossing affects kinematic characteristics and muscle activity. Sixteen healthy, young adults performed two tasks (a)while wearing slippers and (b)while barefoot: (1)level walking and (2)crossing a 10-cm obstacle. Toe clearance, joint angles, muscle activity, and cocontraction were measured for both the leading and trailing lower limbs. In the slipper-wearing condition, knee flexion and hip flexion angles were significantly increased in the swing phase for the leading limb (p < .001 and p < .001, respectively) and trailing limb (p < .001 and p = .004, respectively) compared with the barefoot condition. Tibialis anterior activity (p = .01) and muscle cocontraction of the tibialis anterior and the medial head of the gastrocnemius (p = .047) were significantly increased in the swing phase of the trailing limb for the slipper-wearing condition compared with the barefoot condition in the obstacle crossing task. Wearing slippers increased knee and hip flexion angles, and muscle cocontraction of the tibialis anterior and medial head of gastrocnemius increased during obstacle crossing. The results revealed that obstacle crossing while wearing slippers would require foot fixation adjustment in addition to increased knee and hip flexion to avoid toe collision.

Peroneus Brevis to Longus Tendon Transfer in the Treatment of the Flexible Progressive Collapsing Foot Deformity: A Cadaveric Study

Category: Midfoot/Forefoot; Hindfoot Introduction/Purpose: Although operative treatment of the flexible progressive collapsing foot deformity (PCFD) remains controversial, correction of residual forefoot varus and stabilization of the medial column are important components of reconstruction. An opening wedge medial cuneiform osteotomy or first tarsometatarsal fusion is traditionally performed to plantarflex the first metatarsal. More recently, tendon transfers such as a peroneus brevis (PB) to peroneus longus (PL) have been proposed. However, there is little data to support their use. The aim of our study was to determine the effect of an isolated PB- to-PL transfer (PBT) on medial column and hindfoot joint kinematics in a simulated PCFD (sPCFD) cadaveric model using a robotic gait simulator. We hypothesized that a PBT in a sPCFD model would partially restore kinematics to the intact state. Methods: A validated six-degree of freedom robot (Baxter et al., 2016) was used to simulate the stance phase of level walking for 6 mid-tibia cadaveric specimens (3 male; age: 72 ± 8 years). An eight-camera motion capture system was used to track reflective markers fixed to bones of the foot and ankle. Three conditions were tested for each specimen: intact, sPCFD (Henry et al., 2022), and after PBT. The PBT was performed by transecting the PB and advancing the proximal stump 1 cm into the PL (Sanhudo, 2019). Outcome measures included kinematics of the talonavicular, subtalar, and first tarsometatarsal joints. Maximum differences between the PBT and sPCFD conditions and 95% confidence intervals (95%CIs) were calculated. The percent deformity correction was determined by dividing the difference between the PB and sPCFD states by the difference between the intact and sPCFD states at the site of maximum deformity correction. Results: Relative to the sPCFD condition, the PBT resulted in a maximum increase in talonavicular plantarflexion of 1.8° (95%CI 0.9°-2.7°) with 159% correction during midstance, decrease in talonavicular abduction of 1.5° (95%CI 0.3°-2.8°) with 65% correction during midstance, and decrease in talonavicular eversion of 2.4° (95%CI 1.2°-3.8°) with 90% correction during mid-to- late stance. All deformities had consistent correction at the talonavicular joint during stance (Figure 1). Additionally, the PBT resulted in a maximum increase in subtalar plantarflexion by 0.8° (95%CI 0.3°-1.8°) with 155% correction in early stance, decrease in subtalar abduction by 0.8° (95%CI 0.5°-1.2°) with 191% correction during early stance, and decrease in subtalar eversion by 1.5° (95%CI 0.5°-2.2°) with 178% correction during mid-stance. There was no effect on first tarsometatarsal joint kinematics. Conclusion: A PB-to-PL transfer in a sPCFD model resulted in the correction of multiple deformities including increased plantarflexion and decreased abduction at the talonavicular joint compared to the sPCFD without the transfer, most notably during PB activation in stance. The PBT also decreased eversion at the talonavicular and subtalar joints. Our results suggest that the addition of a PBT as part of the surgical management of the flexible PCFD contributes to correction of the residual forefoot varus, midfoot abduction, and hindfoot valgus deformities by plantarflexing through the medial column and removing a deforming force on the foot by the PB.