Heel Strike Research Articles

Biomechanical analysis of the paravertebral muscle status using imaging methods

Introduction: In recent decades, people’s lifestyles, physical activities, working conditions and habits have dramatically changed, leading to a major increase in the incidence of low back pain (LBP) and lumbar disc herniation (LDH), which is due to the lack of early functional diagnosis. The purpose of this observational study is to analyse paravertebral muscle imbalances. Methodology: The study included 8 participants (mean age: 28 years) with no lumbar spine pathology or symptoms. The assessment was performed during two gait cycles to analyse muscle strength balance in the right/left spinal erectors - iliolumbar muscles across three phases: heel strike (phase I), left foot stance (phase II) and left foot toe-off (phase III). The VICON Motion System was used to collect data for BoB (Biomechanics of Bodies) software to quantify muscle strength in the lumbar region. Results: The data recorded for paravertebral muscles are: phase I - 24.67 N (left), 9.34 N (right), imbalance 37%; phase II - 15.67 N (left), 4.67 N (right), imbalance 29.62%; phase III - 8.81 N (left), 6.42 N (right), imbalance 72.87%. An important left/right imbalance occurs in phase III where muscle strength has close values. Significantly different left/right values and large imbalances occur in phases I and III, which indicates major asymmetry that may cause instability. Conclusion: Segmental assessment of the behaviour of paravertebral muscles, especially spinal erectors, can provide information about the possibility of developing vertebral instability due to muscle failure and is the starting point for assessing various daily activities.

Gait Adaptation to a Phase-Specific Nociceptive Electrical Stimulation Applied at the Ankle: A Model to Study Musculoskeletal-Like Pain.

Introduction: Lower limb pain, whether induced experimentally or as a result of a musculoskeletal injury, can impair motor control, leading to gait adaptations such as increased muscle stiffness or modified load distribution around joints. These adaptations may initially reduce pain but can also lead to longer-term maladaptive plasticity and to the development of chronic pain. In humans, many current experimental musculoskeletal-like pain models are invasive, and most don’t accurately reproduce the movement-related characteristics of musculoskeletal pain. The main objective of this study was to measure pain adaptation strategies during gait of a musculoskeletal-like experimental pain protocol induced by phase-specific, non-invasive electrical stimulation.Methods: Sixteen healthy participants walked on a treadmill at 4 km/h for three consecutive periods (BASELINE, PAIN, and POST-PAIN). Painful electrical stimulations were delivered at heel strike for the duration of heel contact (HC) using electrodes placed around the right lateral malleolus to mimic ankle sprains. Gait adaptations were quantified bilaterally using instrumented pressure-sensitive insoles. One-way ANOVAs and group time course analyses were performed to characterize the impact of electrical stimulation on heel and forefoot contact pressure and contact duration.Results: During the first few painful strides, peak HC pressure decreased on the painful side (8.6 ± 1.0%, p < 0.0001) and increased on the non-stimulated side (11.9 ± 0.9%, p < 0.0001) while HC duration was significantly reduced bilaterally (painful: 12.1 ± 0.9%, p < 0.0001; non-stimulated: 4.8 ± 0.8%, p < 0.0001). No clinically meaningful modifications were observed for the forefoot. One minute after the onset of painful stimulation, perceived pain levels stabilized and peak HC pressure remained significantly decreased on the painful side, while the other gait adaptations returned to pre-stimulation values.Discussion: These results demonstrate that a non-invasive, phase-specific pain can produce a stable painful gait pattern. Therefore, this protocol will be useful to study musculoskeletal pain locomotor adaptation strategies under controlled conditions.

Validation of a Sensor-Based Gait Analysis System with a Gold-Standard Motion Capture System in Patients with Parkinson's Disease.

Digital technologies provide the opportunity to analyze gait patterns in patients with Parkinson’s Disease using wearable sensors in clinical settings and a home environment. Confirming the technical validity of inertial sensors with a 3D motion capture system is a necessary step for the clinical application of sensor-based gait analysis. Therefore, the objective of this study was to compare gait parameters measured by a mobile sensor-based gait analysis system and a motion capture system as the gold standard. Gait parameters of 37 patients were compared between both systems after performing a standardized 5 × 10 m walking test by reliability analysis using intra-class correlation and Bland–Altman plots. Additionally, gait parameters of an age-matched healthy control group (n = 14) were compared to the Parkinson cohort. Gait parameters representing bradykinesia and short steps showed excellent reliability (ICC > 0.96). Shuffling gait parameters reached ICC > 0.82. In a stridewise synchronization, no differences were observed for gait speed, stride length, stride time, relative stance and swing time (p > 0.05). In contrast, heel strike, toe off and toe clearance significantly differed between both systems (p < 0.01). Both gait analysis systems distinguish Parkinson patients from controls. Our results indicate that wearable sensors generate valid gait parameters compared to the motion capture system and can consequently be used for clinically relevant gait recordings in flexible environments.

In Silico of Different Gait Cycle in Customised Leg Orthosis: A Finite Element Approach

Leg orthosis is one of medical device for fracture bone treatment. Several complications have been reported when patients are wearing the conventional Plaster of Paris or fibreglass leg orthosis. Its including numbness due to tight application, swelling, venous congestion and skin irritation. Therefore, the aim of this study is to develop and biomechanical analyse a customized leg cast that could tackle those complications. First, the leg was scanned using a 3D scanner. The leg cast was constructed from a 3D scanned leg model and designed using 3-Matic software which later simulated in finite element analysis using Marc software. The study focuses on three gait cycles; midstance, heel strike and toe off where stress and deformation were predicted. From the results, the cast only supported the ankle in midstance phase with only 7.297MPa stress and not capable to support the ankle in heel strike and toe off phases with maximum stress of 106.99 MPa and 213.12 MPa, respectively, which are beyond its yield strength of ABS, 23MPa. The average of overall displacement occurred for both skin and cast were less than 1.5mm. In short, the cast could only support the ankle in midstance phase and cannot be used for heel strike.

Residual limb shear strain during gait is correlated with patient reported outcomes for persons with transfemoral amputation

The purpose of this study was to measure residual limb skin strain and strain rate within the socket during gait in individuals with a transfemoral amputation and to determine if skin strain during gait is related to patient-reported comfort and function. It was hypothesized that greater skin strain and skin strain rate would correlate to worse patient-reported outcomes. It was also hypothesized that skin strain would progressively increase from the distal to the proximal end of the residuum and maximum strain would occur shortly after heel strike. Dynamic biplane radiography (DBR), combined with conventional motion capture, was used to measure skin deformation within the socket during treadmill walking for 10 persons with unilateral transfemoral amputation. The questionnaire for persons with a transfemoral amputation (Q-TFA) was administered to assess prosthetic use, mobility, health problems, and global health. Q-TFA Prosthetic Use score and Problem score were negatively correlated with the peak shear strains in the proximal and distal regions of the residuum, respectively. Maximum shear strain increased progressively from proximal to distal regions of the residual limb. Within-subject variability in shear strain waveforms during gait was 0.7% or less, but between-subject variability was 3.3% to 5.0% shear. This study demonstrates that skin shear within the socket of persons with transfemoral amputation can be measured during gait using DBR and the results suggest that greater skin shear in the proximal region of the socket is related to decreased prosthetic use.

In vivo analysis of hip joint loading on Nordic walking novices

ObjectiveTo evaluate the influence of Nordic walking (NW) on hip joint loads in order to determine whether it can be safely performed during postoperative physiotherapy in patients after orthopeadic surgery of the hip.MethodsInternal hip joint loads were directly measured in vivo in 6 patients using instrumented hip prostheses during NW and ordinary walking (OW). All patients received training in two different NW techniques (double-poling and the diagonal technique) by a certified NW instructor. Measurements were conducted on a treadmill at a speed of 4 km/h on level ground, at 10% inclination and at 10% slope as well as on a level lawn at a self chosen comfortable speed. Resultant contact force (Fres), bending moment (Mbend) and torsional torque (Mtors) were compared between NW and OW as well as between both NW techniques.ResultsJoint loads showed a double peak pattern during all setups. Neither NW technique significantly influenced hip joint loads at the time of the first load peak during contralateral toe-off (CTO), which was also the absolute load peak, in comparison to OW. Compared to OW, double-poling significantly reduced Fres and Mbend at the time of the second load peak during the contralateral heel strike (CHS) on level ground both on the treadmill (− 6% and − 7%, respectively) and on the lawn (− 7% and − 9%). At 10% inclination, the diagonal technique increased Fres and Mbend at CHS (by + 6% and + 7%), but did not increase the absolute load peak at CTO.ConclusionJoint loads during NW are comparable to those of OW. Therefore, NW can be considered a low-impact activity and seems to be safe for patients that are allowed full weight bearing, e.g. during postoperative rehabilitation after THA.

Effects of nail softness and stiffness with distance running shoes on ground reaction forces and vertical loading rates in male elite long-distance runners with pronated feet

BackgroundTo improve propulsion during running, athletes often wear spike shoes designed for training and/or competition. Running with spike shoes may cause pain and/or injuries. To address this problem, a modified spike shoe was tested. This study aimed to evaluate the effects of running with dual-versus single-stiffness spike running shoes on running mechanics in long-distance runners with pronated feet.MethodsSixteen male elite (national competitive level) runners (5000 or 10,000 m) aged 28.2 ± 2.5 years with pronated feet volunteered to participate in this study. To be included, participants had to have achieved personal best race times over 5- and/or 10-km races under 17 or 34 min during official running competitions. All participants were heel strikers and had a history of 11.2 ± 4.2 years of training. For the assessment of running kinetics, a force plate was imbedded into a walkway. Running kinematics were recorded using a Vicon-motion-capture system. Nike Zoom Rival shoes (Nike, Nike Zoom Rival, USA) were selected and adapted according to spike softness and stiffness. Participants ran at a constant speed of ~4.0 m/s across the walkway with both shoe conditions in randomized order. Six trials were recorded per condition. The main outcomes included peak ground reaction forces and their time-to-peak, average and instantaneous vertical loading rates, free moments, and peak ankle eversion angles.ResultsPaired t-tests revealed significantly lower lateral (p = 0.021, d = 0.95) and vertical (p = 0.010, d = 1.40) forces at heel contact during running with dual-stiffness spike shoes. Running with dual-stiffness spike shoes resulted in a significantly longer time-to-peak vertical (p = 0.004, d = 1.40) force at heel contact. The analysis revealed significantly lower average (p = 0.005, d = 0.46) and instantaneous (p = 0.021, d = 0.49) loading rates and peak negative free moment amplitudes (p = 0.016, d = 0.81) when running with dual-stiffness spike shoes. Finally, significantly lower peak ankle eversion angles were observed with dual-stiffness spike shoes (p < 0.001, d = 1.29).ConclusionsRunning in dual- compared with single-stiffness spike distance running shoes resulted in lower loading rates, free moment amplitudes, and peak ankle eversion angles of long-distance runners with pronated feet.

Radiography and frontal plane knee dynamics in Achondroplasia during walking and running

Gait analysis studies in patients with femoroacetabular impingement syndrome focused until today on alterations in pelvic and hip mechanics, but distal articulations in this syndrome were not explored. Viewing the inter-relationships between foot and hip mechanics and the importance of the subtalar joint in load attenuation at heel strike and during forward propulsion thereafter, alterations in hindfoot mechanics in this syndrome may have clinical significance.Three-dimensional gait kinematics were explored with emphasis on hindfoot mechanics in a group of 15 men with cam-type femoroacetabular impingement and compared to 15 healthy men.Subjects with femoroacetabular impingement had decreased pelvic internal rotation (effect size = 0.70) and hip abduction (effect size = 0.86) at heel strike, and increased sagittal pelvic range of motion during the stance (effect size = 0.81), compared to controls. At the hindfoot level, subjects with femoroacetabular impingement had inverted position at heel strike compared to neutral position in controls (effect size = 0.89), and reduced maximum hindfoot eversion during the stance (effect size = 0.72). Range of motion from heel strike to maximum eversion was not different between the groups (effect size = 0.21).Young adult men with cam-type femoroacetabular impingement syndrome present excessively inverted hindfoot at the moment of heel strike and reduction in maximum eversion during the stance phase. Viewing the deleterious effects of hindfoot malalignment on load attenuation during the stance, custom-designed insoles may be a consideration in this population and this should be investigated further.

Design and Analysis of Various Thermoplastic for Optimized Ankle Foot Orthosis

An ankle-foot orthosis (AFO) is the brace that provides the assist and support to the patient with dorsiflexor weakness. However, standard AFO does not provide comfortable fit and is quite heavy for the user. The main objective of this study is redesign the standard AFO based on topology optimization to overcome the problems caused by the standardized AFO. With the computer-aided design (CAD), the AFO is designed based on parameters from the actual size of the adult leg. The thickness and the trim lines were also considered during the design the 3D model. The AFO was simulated with different materials and thicknesses to determine the effect on stress and deflection. Three different thicknesses of AFO; 3mm, 4mm, and 5mm and three different materials; polypropylene (PP), high-density polyethylene (HDPE) and polylactide (PLA) were used in the simulation. Shape optimization technique is used to optimize the material usage in the design of the AFO in order to reduce materials cost and weight. The optimized AFO was compared to the original AFO in terms of strength and flexibility. The 3mm and 4mm average displacement increase to approximately from 23% to 24% to all type of materials during foot flat and heel rise. 4mm model maximum stress decrease by 27% during heel strike, 22% during foot flat, and 20% during heel rise. The weight reduction from the initial AFO model to the optimization AFO model for both 3mm and 4mm thickness is 26% weight reduction and for 5mm thickness, is a 19%.

A ‘Giving way’ captured during walking by gyroscopes and plantar force sensors

‘Giving way’ is a rapid inversion of the rear part of the foot, which does not result in an acute lateral ankle sprain. It is a specific event for patients with chronic ankle instability (CAI). This report described a ‘giving way’ in an 18-year-old female with CAI, which was biomechanically captured during walking on the flat surface. Shoes with unstable heel having a hemisphere rubber on the sole of the heel were used to provoke ‘giving way’. To the authors’ knowledge, this is the first report describing the kinetics of ‘giving way’ during walking. The event of ‘giving way’ was captured by an Inertial Motor Unit located on the dorsum of the foot and an insole-shaped plantar force measurement device. ‘Giving way’ provided distinctive data on both kinds of devices. Gyroscope data showed a rapid increase of inversion/plantarflexion/internal rotation (maximum levels: 204/280/346 degree/s) and following eversion/dorsiflexion/external rotation (maximum levels: 509/798/797 degree/s) of the foot segment at 350 ms − 492 ms after the heel strike. Plantar force data demonstrated the rapid decrease and subsequent recovery of the regional force on the head of 1st metatarsal head, suggesting a rapid inversion followed by the foot’s defensive eversion. Although the maximum angular velocity of the inversion was smaller and the duration of inversion phase of ‘giving way’ was shorter than in previous reports, the characteristics of the following eversion phase of ‘giving way’ were consistent with earlier reports. The eversion must be a more specific phase than the inversion in the kinematics of ‘giving way’.

Design and analysis of magnetorheological damper based ankle-foot prosthesis prototype

PurposeThis paper aims to design and analyze a controlled magnetorheological damper-based ankle-foot prosthesis prototype.Design/methodology/approachThe ankle-foot prostheses prototype is proposed using the lightweight three dimensional (3 D)-printed parts, MR damper and digital servomotor. Initially, the computer-aided design (CAD) model of the prosthetic foot, leaf spring, retention spring and the various connecting parts required to connect the pylon and damper actuator assemblies are designed using CAD software. Later, the fused deposition modeling 3 D printer-based technique prints a prosthetic foot and other connecting parts using Acrylonitrile Butadiene Styrene filament. The prototype consists of two control parts: the first part controls the MR actuator that absorbs the impacts during walking. The second part is the control of the electric actuator intended to generate the dorsiflexion and plantar flexion movements. Finally, the prototype is tested on a transtibial amputee under the supervision of a prosthetist.FindingsThe ANalysis SYStems software-based analysis has shown that the prosthetic foot has a factor of safety values between 4.7 and 8.7 for heel strike, mid-swing and toe-off; hence, it is safe from mechanical failure. The designed MR damper-based ankle-foot prosthesis prototype is tested on an amputee for a level-ground walk; he felt comfortable compared to his passive prosthesis.Originality/valueThe design of an MR damper-based prosthesis prototype offers a better dynamic range for locomotion than passive prostheses. It reduces the injuries and provides relief to the transtibial amputees.

An inertial sensing mechanism for measuring gait parameters and gait energy expenditure

Sensing, and the associated analytics, is a key module of any active assistive device in physical rehabilitation. Two attributes of interest for active assistive devices in enabling human locomotion are the gait cycle parameter detection and gait Energy Expenditure (EE) estimation. Traditionally these are treated independently from a sensing/analytics perspective. Gait cycle detection is usually done with cameras/inertial sensors and gait EE is performed using metabolic measuring devices (specifically the measurement of Volume of Oxygen (VO2)). This paper presents a novel sensing mechanism using a single Inertial Measurement Unit (IMU) sensor system placed at the ankle, to measure and estimate both gait cycle parameters and gait energy expenditure. This proposed work supports active assistance techniques such as Functional Electrical Stimulation (FES) and Exoskeleton from a sensing/analytics perspective.Data was collected from two volunteers (aged 22, male and healthy). The collected data is passed through a Long Short Term Memory (LSTM) algorithm to train deep neural network, to predict the gait events such as Heel Strike (HS), Heel Off (HO) and Toe Off (TO). The predicted heel strike value is 10 ms delay from an actual value. From the predicted HS value, VO2 consumption of the corresponding person is calculated. Two subjects are taken for clinical trials and obtained error less than 20%.

Acute Effects of a Perturbation-Based Balance Training on Cognitive Performance in Healthy Older Adults: A Pilot Study.

Aging is accompanied by an alteration in the capacity to ambulate, react to external balance perturbations, and resolve cognitive tasks. Perturbation-based balance training has been used to induce adaptations of gait stability and reduce fall risk. The compensatory reactions generated in response to external perturbations depend on the activation of specific neural structures. This suggests that training balance recovery reactions should show acute cognitive training effects. This study aims to investigate whether exposure to repeated balance perturbations while walking can produce acute aftereffects that improve proactive and reactive strategies to control gait stability and cognitive performance in healthy older adults. It is expected that an adaptation of the recovery reactions would be associated with increased selective attention and information processing speed. Twenty-eight healthy older adults were assigned to either an Experimental (EG) or a Control Group (CG). The protocol was divided in 2 days. During the first visit, all participants completed the Symbol Digit Modalities Test (SDMT) and the Trail Making Test (TMT). During the second visit, a cable-driven robot was used to apply waist-pull perturbations while walking on a treadmill. The EG was trained with multidirectional perturbations of increasing intensity. The CG walked for a comparable amount of time with cables on, but without experiencing perturbations. Before and after the training, all participants were exposed to diagonal waist-pull perturbations. Changes in gait stability were evaluated by comparing the distance between the heel of the leading leg and the extrapolated Center of Mass (Heel-XCoM Distance—HXD) at perturbation onset (PON) and first compensatory heel strike (CHS). Finally, the cables were removed, and participants completed the SDMT and the TMT again. Results showed that only the EG adapted the gait stability (p < 0.001) in reaction to diagonal perturbations and showed improved performance in the SDMT (p < 0.001). This study provides the first evidence that a single session of perturbation-based balance training produce acute aftereffects in terms of increased cognitive performance and gait stability in healthy older adults. Future studies will include measures of functional activation of the cerebral cortex and examine whether a multi-session training will demonstrate chronic effects.

Importance of dynamics in the finite element prediction of plastic damage of polyethylene acetabular liners under edge loading conditions

After hip replacement, in cases where there is instability at the joint, contact between the femoral head and the acetabular liner can move from the bearing surface to the liner rim, generating edge loading conditions. This has been linked to polyethylene liner fracture and led to the development of a regulatory testing standard (ISO 14242:4) to replicate these conditions. Performing computational modelling alongside simulator testing can provide insight into the complex damage mechanisms present in hard-on-soft bearings under edge loading. The aim of this work was to evaluate the need for inertia and elastoplastic material properties to predict kinematics (likelihood of edge loading) and plastic strain accumulation (as a damage indicator).While a static, rigid model was sufficient to predict kinematics for experimental test planning, the inclusion of inertia, alongside elastoplastic material, was required for prediction of plastic strain behaviour. The delay in device realignment during heel strike, caused by inertia, substantially increased the force experienced during rim loading (e.g. 600 N static rigid, ∼1800 N dynamic elastoplastic, in one case). The accumulation of plastic strain is influenced by factors including cup orientation, swing phase force balance, the moving mass, and the design of the device itself. Evaluation of future liner designs could employ dynamic elastoplastic models to investigate the effect of design feature changes on bearing resilience under edge loading.

A Wearable Sensor-based System For Gait Analysis That Is Robust To Gait Variations

Gait analysis is widely used to assess deficits following sports injuries or monitor recovery during rehabilitation [1]. While traditional technologies such as motion capture systems and instrumented force plates can be used to measure kinematics during relevant phases of gait, they are confined to lab environments. Advances in inertial measurement unit (IMU) technology provide alternative prospects for portable assessment of both gait events and kinematics. PURPOSE: Evaluate IMU-based system (wearable sensors and autonomous detection algorithms) for detecting gait events and monitoring range of motion (ROM) under controlled gait variations similar to those observed following an injury [1-3]. METHODS: 10 healthy participants (5 M, 5 F, 26.5 ± 2 y.o.) were instrumented with 6 IMUs (Delsys Inc., USA) placed on the sacrum and sternum and bilaterally on the lower/upper legs. Force sensitive resisters (FSR; placed under each foot) and motion capture (Vicon, UK) outcomes were used as gold standard for validating gait events and kinematic measures, respectively. Subjects walked on a treadmill with normal gait followed by gait alterations including: 1) reduced sagittal knee ROM by >30%, 2) reduced sagittal hip ROM by >20%, and 3) increased trunk obliquity by >10%. These gait variations were chosen for their relevance to sport-related injuries such as ACL tear or abdominal strain [1-3]. Our detection algorithms used lower leg IMU data to identify heel strike and toe off, with cycle duration as the time between heel strikes; and IMU data from upper/lower leg, upper leg/sacrum, and sternum to compute knee, hip, and trunk ROM respectively. RESULTS: Cycle duration was detected with <0.5% error with respect to FSRs, and heel strike and toe off were detected within <5% of gait duration across trials, subjects, and gait variations. Knee, hip and trunk ROM were within 5 degrees of those obtained using motion capture for both normal and altered gait. CONCLUSION: Our wearable IMU-based system can accurately detect gait events and calculate gait kinematics during a range of controlled gait variations similar to those resulting from sports injuries. 1] Gokeler et al. Int J Sports Phys Ther, 2013. 2] Young et al. Am J Sports Med, 2014. 3] Hewett et al. Exerc Sport Sci Rev, 2011. Acknowledgments: Work supported in part by NINDS R43HD100209.

Correlation Analysis on the Effects of Wearing Compression Socks and Smooth Socks on Running Kinematics among Runners

This study was conducted to determine running kinematics while using compression socks (CS) and smooth socks (SS) among 16 recreational runners. They were required to complete a maximal treadmill test with two different running sock conditions (smooth and compression). All kinematic parameters (ground contact time, heel strike, stride length and swing time) were reported in an average of the four stages of Bruce protocol. Results showed more significant correlations (p&lt;0.05) among the kinematic variables in the compression socks condition as compared to the smooth socks. In conclusion, wearing compression socks improves movement kinematics while running may be due to the enriched somatosensory information received by the foot. Keywords: Running; Compression socks; Movement kinematics; Somatosensory feedback eISSN: 2398-4287© 2021. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians/Africans/Arabians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning &amp; Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v6iSI4.2915

What Is the Impact of a CAM Impingement on the Gait Cycle in Patients with Progressive Osteoarthritis of the Hip?

(1) Background: The femoroacetabular impingement (FAI) type cam leads to a conflict between the acetabular rim and a bony thickening of the femoral neck junction. While maximal excursions in flexion, adduction and internal rotation provoke pain, the aim of this study was to analyze if a cam morphology shows an impact on gait pattern. (2) Methods: Fifty-five patients with end-stage hip osteoarthritis performed gait analysis before hip replacement as well as three, six and 12 months postoperatively. Thirty-three (60%) of them presented an FAI type cam. An ANOVA was used to compare the hip angles in sagittal, frontal and transversal planes between patients with a FAI type cam (group “+cam”) and without (group “−cam”). (3) Results: Before surgery the patients of the +cam-group showed a tendency towards a reduced flexion and internal rotation at the heel strike (p &gt; 0.05). Over time, the differences were adjusted by total hip arthroplasty. (4) Conclusions: We did not find any differences in the gait analysis of patients with a FAI type cam compared to patients without.

Increases in Load Carriage Magnitude and Forced Marching Change Lower-Extremity Coordination in Physically Active, Recruit-Aged Women

The objective was to examine the interactive effects of load magnitude and locomotion pattern on lower-extremity joint angles and intralimb coordination in recruit-aged women. Twelve women walked, ran, and forced marched at body weight and with loads of +25%, and +45% of body weight on an instrumented treadmill with infrared cameras. Joint angles were assessed in the sagittal plane. Intralimb coordination of the thigh-shank and shank-foot couple was assessed with continuous relative phase. Mean absolute relative phase (entire stride) and deviation phase (stance phase) were calculated from continuous relative phase. At heel strike, forced marching exhibited greater (P < .001) hip flexion, knee extension, and ankle plantar flexion compared with running. At mid-stance, knee flexion (P = .007) and ankle dorsiflexion (P = .04) increased with increased load magnitude for all locomotion patterns. Forced marching (P = .009) demonstrated a "stiff-legged" locomotion pattern compared with running, evidenced by the more in-phase mean absolute relative phase values. Running (P = .03) and walking (P = .003) had greater deviation phase than forced marching. Deviation phase increased for running (P = .03) and walking (P < .001) with increased load magnitude but not for forced marching. With loads of >25% of body weight, forced marching may increase risk of injury due to inhibited energy attenuation up the kinetic chain and lack of variability to disperse force across different supportive structures.

Analysis of hip joint loading during walking with different shoe types using instrumented total hip prostheses

Hip joint loads need careful consideration during postoperative physiotherapy after joint replacement. One factor influencing joint loads is the choice of footwear, but it remains unclear which footwear is favorable. The objective of the present study was to investigate the influence of footwear on hip joint loads in vivo. Instrumented hip endoprostheses were used for in vivo load measurements. The parameters resultant contact force (Fres), bending moment (Mbend) and torsional moment (Mtors) were evaluated during treadmill walking at 4 km/h with different shoe types. In general, footwear tended to increase hip joint loading, with the barefoot shoe having the least influence. Fres and Mbend were significantly increased during heel strike for all shoe types in comparison to barefoot walking, with everyday shoe (34.6%; p = 0.028 and 47%; p = 0.028, respectively) and men’s shoe (33.2%; p = 0.043 and 41.1%; p = 0.043, respectively) resulting in the highest changes. Mtors at AbsMax was increased by all shoes except for the barefoot shoe, with the highest changes for men’s shoe (+ 17.6%, p = 0.043) and the shoe with stiffened sole (+ 17.5%, p = 0.08). Shoes, especially those with stiff soles or elaborate cuishing and guiding elements, increase hip joint loads during walking. The influence on peak loads is higher for Mtors than for Fres and Mbend. For patients in which a reduction of hip joints loads is desired, e.g. during physiotherapy after recent surgery or to alleviate symptoms of osteoarthritis, low profile shoes with a flexible sole may be preferred over shoes with a stiff sole or elaborate cushioning elements.

Evaluating the Accuracy of Virtual Reality Trackers for Computing Spatiotemporal Gait Parameters.

Ageing, disease, and injuries result in movement defects that affect daily life. Gait analysis is a vital tool for understanding and evaluating these movement dysfunctions. In recent years, the use of virtual reality (VR) to observe motion and offer augmented clinical care has increased. Although VR-based methodologies have shown benefits in improving gait functions, their validity against more traditional methods (e.g., cameras or instrumented walkways) is yet to be established. In this work, we propose a procedure aimed at testing the accuracy and viability of a VIVE Virtual Reality system for gait analysis. Seven young healthy subjects were asked to walk along an instrumented walkway while wearing VR trackers. Heel strike (HS) and toe off (TO) events were assessed using the VIVE system and the instrumented walkway, along with stride length (SL), stride time (ST), stride width (SW), stride velocity (SV), and stance/swing percentage (STC, SWC%). Results from the VR were compared with the instrumented walkway in terms of detection offset for time events and root mean square error (RMSE) for gait features. An absolute offset between VR- and walkway-based data of (15.3 ± 12.8) ms for HS, (17.6 ± 14.8) ms for TOs and an RMSE of 2.6 cm for SW, 2.0 cm for SL, 17.4 ms for ST, 2.2 m/s for SV, and 2.1% for stance and swing percentage were obtained. Our findings show VR-based systems can accurately monitor gait while also offering new perspectives for VR augmented analysis.