Angular Kinematics Research Articles

Characterization of normative angular joint kinematics during two functional upper limb tasks

BackgroundOptical motion capture is a powerful tool for assessing upper body kinematics, including compensatory movements, in different populations. However, the lack of a standardized protocol with clear functional relevance hinders its clinical acceptance. Research questionThe objective of this study was to use motion capture to: (1) characterize angular joint kinematics in a normative population performing two complex, yet standardized upper limb tasks with clear functional relevance; and (2) assess the protocol’s intra-rater reliability. MethodsTwenty non-disabled adults performed the previously developed Pasta Box Task and Cup Transfer Task. The kinematics of the upper body were captured using an optoelectronic motion capture system and rigid plates with reflective markers. Angular joint trajectories, peak angle, range of motion (RoM), and peak angular velocity were extracted for the trunk, shoulder, elbow, forearm, and wrist. Intra-class correlation was used to assess the intra-rater reliability of the kinematic measures. ResultsBoth tasks required minimal trunk motion. Cross-body movements required greater RoM at the trunk, shoulder, and elbow joints compared to movements in front of the body. Reaches to objects further away from the body required greater trunk and elbow joint RoM compared to reaches to objects closer to the body. Transporting the box of pasta required the wrist to maintain an extended position. The two different grasp patterns in the Cup Transfer Task forced the wrist into a flexed and ulnar-deviated position for the near cup, and an extended and radial-deviated position for the far cup. For both tasks, the majority of measures displayed intra-class correlation values above 0.75, indicating good reliability. SignificanceOur protocol and functional tasks elicit a degree of movement sensitivity that is not available in current clinical assessments. Our study also provides a comprehensive dataset that can serve as a normative benchmark for quantifying movement compensations following impairment.

Head impact magnitudes that occur from purposeful soccer heading depend on the game scenario and head impact location

PurposeThis study quantified the linear and angular kinematics that result from purposeful heading during youth soccer games, and the influence of game scenario and head impact location on these magnitudes. MethodThis observational study recruited thirty-six female soccer players (13.4 ± 0.9 years old) from three elite youth soccer teams (U13, U14, U15) and followed for an entire soccer season. Players wore wireless sensors during each game to quantify head impact magnitudes. A total of 60 regular season games (20 games per team) were video recorded, and purposeful heading events were categorized by game scenario (e.g. throw in), and head impact location (e.g. front of head). ResultsGame scenario had a statistically significant effect on the linear head acceleration, and rotational head velocity, that resulted from purposeful headers. Rotational velocity from purposeful headers varied significantly between head impact locations, with impacts to the top of the head (improper technique) resulting in larger peak rotational velocities than impacts to the front of the head (proper technique); this was also the case for the linear acceleration for punts. ConclusionOur findings suggest that the magnitude for both linear and angular head impact kinematics depend on the game scenario and head impact location. Headers performed with the top of the head (improper technique) result in larger rotational velocities compared to the front of the head (proper technique). Accordingly, youth players should be educated on how to execute proper heading technique to reduce head impact accelerations.

Three-Dimensional Human Gait Pattern: Reference Data for Young, Active Women Walking with Low, Preferred, and High Speeds.

Normal gait pattern is the key component in the investigation of pathological gait patterns. In computer motion analysis there is a need to include data from participants with different somatic structures to develop a normative database or to limit the database results to a specific population. The aim of this study was to determine kinematic gait patterns for young, active women walking with low, preferred, and self-selected speeds with regard to their somatic characteristics. Laboratory-based gait analysis was performed on 1320 gait cycles taken from 20 young, active women walking with three different speeds. Comprehensive anthropometric measurements and descriptive statistics were used to describe spatiotemporal and angular variables at each walking condition. The results demonstrated some significant differences in young, active women walking between different speeds and compared to the literature. This suggests that there is a need to include data from participants with different somatic structures to develop a normative database or limit the database results to a specific population. Detailed linear and angular kinematic variables allow for proper adjustment of parameters depending on the gait speed of people with locomotion disorders.

Relationship of the Selected Kinematic Variables with Movement Phases of Two Different Types of Jerk of Weightlifting

The purpose of the study is to find out the relation of selected kinematic variables in movement phases of two different techniques of jerk. Five male inter-university participants in weight lifting of 18 to 25 years of age, who had participated for Lakshmibai National Institute of physical education, Gwalior, were selected as subjects for this study. The selected variable was Angular kinematic variables (drive to jerk, getting under barbell) at various joint and Linear kinematic variables was height of Centre of gravity of the subjects during drive to jerk and getting under the barbell. The obtained data were analyzed by using pearson's product moment correlation. All the data were analyzed by statistical package for Social Science (SPSS) version 20. For testing the level of significance was set at 0.05. The results have exhibited that the obtained value of coefficient of correlation in all angular and linear kinematic variables at all the selected moments have shown insignificant relationship with the time of drop under in split jerk in weight lifting.

Spinal segments do not move together predictably during daily activities

Background: Considering the thoracic, lumbar spine or whole spine as rigid segments has been the norm until recent studies highlighted the importance of more detailed modelling. A better understanding of the requirement for spine multi-segmental analysis could guide planning of future studies and avoid missing clinically-relevant information.Research question: This study aims to assess the correlation between adjacent spine segments movement thereby evaluating segmental redundancy in both healthy and participants with low back pain (LBP).Methods: A 3D motion capture system tracked the movement of upper and lower thoracic and lumbar spine segments in twenty healthy and twenty participants with LBP. Tasks performed included walking, sit-to-stand and lifting, repeated 3 times. 3D angular kinematics were calculated for each spine segment. Segmental redundancy was evaluated through cross-correlation (Rxy) analysis of kinematics time series and correlation of range of motion (RROM) of adjacent spine segments.Results: The upper/lower lumbar pairing showed weak correlations in the LBP group for all tasks and anatomical planes (Rxyrange:0.02–0.36) but moderate and strong correlations during walking (Rxy _frontalplane:0.4) and lifting (Rxy _sagittalplane:0.64) in the healthy group. The lower thoracic/upper lumbar pairing had weak correlations for both groups during lifting and sit-to-stand in the frontal plane and for walking (Rxy:0.01) in the sagittal plane only. The upper/lower thoracic pairing had moderate correlations during sit-to-stand in sagittal and transverse plane in patients with LBP (Rxy _sagittalplane:0.41; Rxy _transverse plane:−0.42) but weak in healthy (Rxy _sagittalplane:0.23; Rxy _transverseplane:−0.34); the contrary was observed during lifting.The majority of RROM values (55/72) demonstrated weak correlations.Significance:The results suggest that multi-segmental analysis of the spine is necessary if spine movement characteristics are to be fully understood. We cannot establish a priori where redundancy occurs based on healthy data, therefore extra consideration should be made when planning studies with pathological cohorts.

Reproducibility of navigation based kinematic analysis of the knee – A cadaveric investigation

PurposeSeveral navigation-based kinematic studies of the knee have been published recently, but little information is available about reproducibility and reliability of the acquired data. The aim of the present study first is to determine reproducibility and reliability of kinematical measurements of healthy knees and knees after TKA (total knee arthroplasty) with regards to rotational and translational measurement parameters. Second the mathematical background, applicability, and limitations of investigating navigation-based kinematics should be compiled. MethodsUsing cadavers fixed by the Thiel method, in ten knees reproducibility of obtained angular and translational kinematic parameters were investigated before and after total knee arthroplasty. For this reason agreement of obtained data of a first and a second movement cycle and the same after a surgical intervention was assessed using a commercially available navigational device. ResultsFor both angular and translational parameters in healthy knees and knees after total knee arthroplasty mean differences between measured parameters of the first and second movement cycle and after surgical intervention of less than 0.5° or millimeters (standard deviation 1.3 or less) or a inter class correlation of 0.92 and more, respectively, was found. DiscussionUse of a commercial navigation system allows highly accurate investigations of knee kinematics in cadavers before and after TKA. This technique, which does not require any specific technical knowledge of the investigator, is in accordance with current accepted biomechanical methods.

Real-time feedrate scheduling for five-axis machining by simultaneously planning linear and angular trajectories

Abstract Feedrate scheduling for five-axis CNC machining is challenging due to the additional non-linear angular motion. Traditional real-time feedrate scheduling methods usually only concern the linear (i.e., tool position) motion, and synchronize the angular (i.e., tool orientation) motion with the linear motion by sharing the same curve parameter. The resultant angular motion will violate the angular constraints and be discontinuous at block junctions. This paper presents a real-time feedrate scheduling method for five-axis machining by simultaneously planning linear and angular trajectories (SLATP). The SLATP treats the angular motion equally with the linear motion, resulting in smooth linear and angular trajectories considering axial kinematic constraints in real time. The linear and angular boundary velocities are firstly determined by implicit circular blending on R 3 and S 2 . Then, the linear and angular trajectories are separately planned with piecewise polynomial profiles. Finally, a bi-directional scanning method with time synchronization is proposed to make the velocity overall continuous. During each scanning, the linear and angular trajectories are time synchronized with an analytical algorithm. The synchronization algorithm is compatible with the traditional bi-directional scanning method and feasible for toolpaths consisting of multiple blocks. The SLATP strictly respects the linear and angular kinematic constraints in the workpiece coordinate system. It can also consider the axial kinematic constraints by mapping these constraints into the workpiece coordinate system. Simulations and experiments have demonstrated that the SLATP can plan smoother axial trajectories within about 140 μs and achieve smaller contour errors compared with traditional real-time methods.

Effect of Cognitive Dual Tasks on Lower Extremity Kinematics and Ground Reaction Force during Repeated Tuck Jump Landings

Many sports-related injuries occur due to a combination of physical, high joints load during sport-specific maneuvers and cognitive factors, such as keeping other players or the ball in short-term memory. This addition of cognitive challenges can degrade physical performance and increase joint loading. However, previous studies have focused on a single movement and it is unknown how cognitive load influences repeated landing that better simulate the continuous demand of athletic performance. PURPOSE: To determine if a cognitive challenge during tuck jumping affect lower extremity landing biomechanics. METHODS: Recreational collegiate athletes (N=20, 71.7±11.9kg, 171.1±9.7cm) participated in this study. A baseline: BASE condition of repeated tuck jumps and a cognitive: COG condition of tuck jumps while performing an addition problem from a stream of digits on a computer screen. The tuck jump consisted of 3 sets of 10 seconds repeated double leg vertical tuck jumps. Dominant-side sagittal plane lower extremity angular kinematics and vertical ground reaction forces (VGRF: 1,000 Hz) were compared between the two conditions paired t-tests (p<.05). RESULTS: COG, compared to the BASE, resulted in increased ankle angle (30.1±1.7° and 29.3±0.7°) and decreased knee angle (20.5±0.6° and 21.5±0.6°) at initial contact. Also, decreased ankle (21.8±1.4° and 22.4±1.0°) and knee (63.0±0.7° and 67.9±0.9°) maximum angle occurred. Additionally, COG resulted in an increased ankle (52.6±0.9° and 51.6±0.9°), decreased knee (42.5±1.2° and 46.4±0.8°) and hip (31.7±1.1° and 33.0±0.7°) displacements. No significant differences were found in VGRF between conditions. CONCLUSION: We surmised that COG, compared to the BASE, change lower extremity biomechanics that may increase injury risk and knee loading. The more extended knee position at initial contact and reduced sagittal displacement during the COG condition may contribute to increased injury risk when under cognitive load. However, greater ankle displacement during the COG condition may be adaptation strategy to protect the knee under cognitive load.

Trunk postural adjustments: Medium-term reliability and correlation with changes of clinical outcomes following an 8-week lumbar stabilization exercise program

BackgroundLow back pain (LBP) has been previously associated with delayed anticipatory postural adjustments (APAs) determined by trunk muscle activation. Lumbar stabilization exercise programs (LSEP) for patients with LBP may restore the trunk neuromuscular control of the lumbar spine, and normalize APAs. This exploratory study aimed at testing the reliability of EMG and kinematics-based postural adjustment measures over an 8-week interval, assessing their sensitivity to LBP status and treatment and examining their relationship with clinical outcomes. MethodsMuscle activation of 10 trunk muscles, using surface electromyography (EMG), and lumbar angular kinematics were recorded during a rapid arm-raising/lowering task. Patients with LBP were tested before and after an 8-week LSEP. Healthy controls receiving no treatment were assessed over the same interval to determine the reliability of the measures and act as a control group at baseline. Muscle activation onsets and reactive range of motion, range of velocities and accelerations were assessed for between group differences at baseline and pre- to post-treatment effects within patients with LBP using t-tests. Correlations between these dependent variables and the change of clinical outcomes (pain, disability) over treatment were also explored. ResultsKinematic-based measures showed comparable reliability to EMG-based measures. Between-group differences were found in lumbar lateral flexion ROM at baseline (patients < controls). In the patients with LBP, lateral flexion velocity and acceleration significantly increased following the LSEP. Correlational analyses revealed that lumbar angular kinematics were more sensitive to changes in pain intensity following the LSEP compared to EMG measures. These findings are interpreted in from the perspective of guarding behaviors and lumbar stability hypotheses. ConclusionFuture clinical trials are needed to target patients with and without delayed APAs at baseline and to explore the sensitivity of different outcome measures related to APAs. Different tasks more challenging to postural stability may need to be explored to more effectively reveal APA dysfunction.

Kinematic Analysis Using 3D Motion Capture of Drinking Task in People With and Without Upper-extremity Impairments

Kinematic analysis is a powerful method for objective assessment of upper extremity movements in a three-dimensional (3D) space. Three-dimensional motion capture with an optoelectronic camera system is considered as golden standard for kinematic movement analysis and is increasingly used as outcome measure to evaluate the movement performance and quality after an injury or disease involving upper extremity movements. This article describes a standardized protocol for kinematic analysis of drinking task applied in individuals with upper extremity impairments after stroke. The drinking task incorporates reaching, grasping and lifting a cup from a table to take a drink, placing the cup back, and moving the hand back to the edge of the table. The sitting position is standardized to the individual's body size and the task is performed in a comfortable self-paced speed and compensatory movements are not constrained. The intention is to keep the task natural and close to a real-life situation to improve the ecological validity of the protocol. A 5-camera motion capture system is used to gather 3D coordinate positions from 9 retroreflective markers positioned on anatomical landmarks of the arm, trunk, and face. A simple single marker placement is used to ensure the feasibility of the protocol in clinical settings. Custom-made Matlab software provides automated and fast analyses of movement data. Temporal kinematics of movement time, velocity, peak velocity, time of peak velocity, and smoothness (number of movement units) along with spatial angular kinematics of shoulder and elbow joint as well as trunk movements are calculated. The drinking task is a valid assessment for individuals with moderate and mild upper extremity impairment. The construct, discriminative and concurrent validity along with responsiveness (sensitivity to change) of the kinematic variables obtained from the drinking task have been established.

Validation of a Custom Instrumented Retainer Form Factor for Measuring Linear and Angular Head Impact Kinematics.

Head impact exposure in popular contact sports is not well understood, especially in the youth population, despite recent advances in impact-sensing technology which has allowed widespread collection of real-time head impact data. Previous studies indicate that a custom-instrumented mouthpiece is a superior method for collecting accurate head acceleration data. The objective of this study was to evaluate the efficacy of mounting a sensor device inside an acrylic retainer form factor to measure six-degrees-of-freedom (6DOF) head kinematic response. This study compares 6DOF mouthpiece kinematics at the head center of gravity (CG) to kinematics measured by an anthropomorphic test device (ATD). This study found that when instrumentation is mounted in the rigid retainer form factor, there is good coupling with the upper dentition and highly accurate kinematic results compared to the ATD. Peak head kinematics were correlated with r2 > 0.98 for both rotational velocity and linear acceleration and r2 = 0.93 for rotational acceleration. These results indicate that a rigid retainer-based form factor is an accurate and promising method of collecting head impact data. This device can be used to study head impacts in helmeted contact sports such as football, hockey, and lacrosse as well as nonhelmeted sports such as soccer and basketball. Understanding the magnitude and frequency of impacts sustained in various sports using an accurate head impact sensor, such as the one presented in this study, will improve our understanding of head impact exposure and sports-related concussion.

Cluster-based upper body marker models for three-dimensional kinematic analysis: Comparison with an anatomical model and reliability analysis

Quantifying angular joint kinematics of the upper body is a useful method for assessing upper limb function. Joint angles are commonly obtained via motion capture, tracking markers placed on anatomical landmarks. This method is associated with limitations including administrative burden, soft tissue artifacts, and intra- and inter-tester variability. An alternative method involves the tracking of rigid marker clusters affixed to body segments, calibrated relative to anatomical landmarks or known joint angles. The accuracy and reliability of applying this cluster method to the upper body has, however, not been comprehensively explored. Our objective was to compare three different upper body cluster models with an anatomical model, with respect to joint angles and reliability. Non-disabled participants performed two standardized functional upper limb tasks with anatomical and cluster markers applied concurrently. Joint angle curves obtained via the marker clusters with three different calibration methods were compared to those from an anatomical model, and between-session reliability was assessed for all models. The cluster models produced joint angle curves which were comparable to and highly correlated with those from the anatomical model, but exhibited notable offsets and differences in sensitivity for some degrees of freedom. Between-session reliability was comparable between all models, and good for most degrees of freedom. Overall, the cluster models produced reliable joint angles that, however, cannot be used interchangeably with anatomical model outputs to calculate kinematic metrics. Cluster models appear to be an adequate, and possibly advantageous alternative to anatomical models when the objective is to assess trends in movement behavior.

Optimization-based motor control of a Paralympic wheelchair athlete

The following research approximated how the central nervous system of Paralympic wheelchair athletes resolve kinematic redundancies during upper-limb movements. A multibody biomechanical model of a tetraplegic Paralympic athlete was developed using subject-specific body segment parameters. The angular joint kinematics throughout a specified Paralympic sport movement (i.e., wheelchair curling) were experimentally measured using inertial measurement units. The motor control system of the Paralympian was mathematically modelled and simulated using forward dynamics optimization. The predicted kinematics from different optimization objective functions (i.e., minimizing resultant joint moments, mechanical joint power, and angular joint velocities and accelerations) were compared with those experimentally measured throughout the wheelchair curling movement. Of the optimization objective functions under consideration, minimizing angular joint accelerations produced the most accurate predictions of the kinematic trajectories (i.e., characterized with the lowest overall root mean square deviations) and the shortest optimization computation time. The implications of these control findings are discussed with regards to optimal wheelchair design through predictive dynamic simulations.

Development of a Novel Technique to Record 3D Intersegmental Angular Kinematics During Dynamic Spine Movements.

A novel method of recording intersegmental spine kinematics was developed. The method was required to: (1) have similar accuracy and precision as current methods that record gross spine kinematics; (2) be reasonably insensitive to errors associated with marker detection or misplacement; and (3) be reasonably insensitive to skin movement artefacts. Four healthy participants performed trunk flexion, lateral bending, and axial twist movements; data were collected using the intersegmental method as well as electromagnetic sensors. Comparing methods, gross angular kinematic differences were within 1 SD during flexion and lateral bend, while axial twist resulted in the largest differences. To test sensitivity to marker error, random error was added to marker positions. The most proximal and distal intersegmental units were the most sensitive to marker error. Adding additional markers at the ends or interpolating padded markers reduced this sensitivity. The influence of skin movement artefact was investigated by digitizing locations of the skin with respect to the spinous processes in both neutral and fully flexed postures. In the lumbar region, large skin artefacts had minimal effect on intersegmental angles. The greatest strength of this method is the ability to dynamically record intersegmental spine kinematics.

Kinematic Changes during Prolonged Fast-Walking in Old and Young Adults.

Walking biomechanics is known to be influenced by speed. However, most of the research examining the effects of walking speed and gait characteristics has been conducted after a fast-walking task, neglecting the changes that may occur during the task. The aim of the present study was to determine the impact of fast-walking over time on kinematics in young and old adults. Twenty-seven young adults (26.6 ± 6.0 years) and 23 old adults (71.0 ± 5.6 years) walked at 70% of their maximum heart rate for 20 min or until exhaustion, and the effects of fast-walking on temporospatial parameters and on angular kinematics were analyzed during the activity. During the protocol, both age-groups increased step-width variability. Significant effects of time were found for the ankle and hip at toe off for the older group. For the younger group, only the ankle angle at heel strike changed over time. For both groups, fast-walking induced changes in the coordination among the lower-limb angles that were more prominent during the swing phase of the gait. In conclusion, lower-limb kinematics changes in young adults were compatible with early signs of fatigue. The increased step-width variability in older adults may indicate an augmented risk of falling. Changes in the lower-limb walking kinematics of old adults suggest that the adjustments for weight acceptance and body propulsion were restricted to the hip and ankle joints. The kinematic changes among the lower-limb joint angles during the swing phase may compromise the quality of gait. These findings provide a foundation for future studies in the assessment of the risk of falls in older adults associated with walking at a faster pace.

A possible correlation between the basal ganglia motor function and the inverse kinematics calculation

The main hypothesis of this study, based on experimental data showing the relations between the BG activities and kinematic variables, is that BG are involved in computing inverse kinematics (IK) as a part of planning and decision-making. Indeed, it is assumed that based on the desired kinematic variables (such as velocity) of a limb in the workspace, angular kinematic variables in the joint configuration space are calculated. Therefore, in this paper, a system-level computational model of BG is proposed based on geometrical rules, which is able to compute IK. Next, the functionality of each part in the presented model is interpreted as a function of a nucleus or a pathway of BG. Moreover, to overcome existing redundancy in possible trajectories, an optimization problem minimizing energy consumption is defined and solved to select an optimal movement trajectory among an infinite number of possible ones. The validity of the model is checked by simulating it to control a three-segment manipulator with rotational joints in a plane. The performance of the model is studied for different types of movement including different reaching movements, a continuous circular movement and a sequence of tracking movements. Furthermore, to demonstrate the physiological similarity of the presented model to the BG structure, the neuronal activity of each part of the model considered as a BG nucleus is verified. Some changes in model parameters, inspired by the dopamine deficiency, also allow simulating some symptoms of Parkinson's disease such as bradykinesia and akinesia.

Therapists’ cues influence lower limb muscle activation and kinematics during gait training in subacute stroke

Purpose: Symmetrical gait is a key goal of rehabilitation post-stroke. Therapists employ techniques such as verbal instruction and haptic cues to increase activation of paretic muscles. We examined whether verbal or tactile cueing altered spatiotemporal gait parameters, kinematics and electromyography (EMG) of lower limb muscles on the more-affected side within a training session.Materials and methods: Patients (n = 10) were recruited from rehabilitation services (<9 months post-stroke). Tactile (to the hip muscles) or verbal cues were provided on two testing days, 7–10 days apart (randomized order). Gait and angular kinematics were recorded using a Vicon motion capture system and muscle activation using EMG; at baseline (PRE), during the cue, directly afterwards without a cue (POST) and 20 min later without a cue (RETEST).Results: Both verbal and tactile cueing significantly increased muscle activity in paretic muscles but with no immediate effect on step length asymmetry. Tactile cues, more than verbal, temporarily altered gait speed, cadence and time in double support. Verbal cues caused more robust increases in muscle activation of vastus lateralis at weight acceptance and medial gastrocnemius activity from toe off to midswing.Conclusions: Within a treatment session, tactile cues more effectively altered cadence and double support time while verbal cues more consistently increased vastus lateralis and medial gastrocnemius activity. The effectiveness of these methods in fostering motor relearning in the longer term is an important area for future research.Implications for RehabilitationTherapist cueing alters muscle activity on hemiparetic side with no effects on symmetry.Tactile cues, more so than verbal cues, increase cadence and reduce time in double support.Verbal cues are more effective at increasing vastus lateralis and plantarflexor muscle activity.

Inverse Dynamics Modeling of Paralympic Wheelchair Curling

Paralympic wheelchair curling is an adapted version of Olympic curling played by individuals with spinal cord injuries, cerebral palsy, multiple sclerosis, and lower extremity amputations. To the best of the authors' knowledge, there has been no experimental or computational research published regarding the biomechanics of wheelchair curling. Accordingly, the objective of the presentresearch was to quantify the angular joint kinematics and dynamics of a Paralympic wheelchair curler throughout the delivery. The angular joint kinematics of the upper extremity were experimentally measured using an inertial measurement unit system; the translational kinematics of the curling stone were additionally evaluated with optical motion capture. The experimental kinematics were mathematically optimized to satisfy the kinematic constraints of a subject-specific multibody biomechanical model. The optimized kinematics were subsequently used to compute the resultant joint moments via inverse dynamics analysis. The main biomechanical demands throughout the delivery (ie, in terms of both kinematic and dynamic variables) were about the hip and shoulder joints, followed sequentially by the elbow and wrist. The implications of these findings are discussed in relation to wheelchair curling delivery technique, musculoskeletal modeling, and forward dynamic simulations.

Effects of Novel Guidance Tubing Gait on Electromyographic Neuromuscular Imbalance and Joint Angular Kinematics During Locomotion in Hemiparetic Stroke Patients

ObjectiveTo compare the immediate effects of conventional treadmill gait and guidance tubing gait (GTG) on electromyographic neuromuscular imbalance and knee joint kinematics in hemiparetic gait. DesignCase-control study. SettingUniversity medical center. ParticipantsParticipants (N=33; 19 men, 14 women) were patients with hemiparetic stroke (n=18 [experimental]; mean age ± SD, 39.2±16.8y) and healthy controls (n=15; mean age ± SD, 26.3±2.6y). InterventionsThe GTG was provided for approximately 30 minutes and involved application of an assistive guidance force using the tubing, specifically to improve knee joint stabilization during midstance and increase knee joint flexion during midswing phase. Main Outcome MeasuresClinical tests included the Korean Mini-Mental State Examination, Modified Ashworth Scale, Berg Balance Scale, manual muscle test, and knee joint range of motion and sensory tests. Knee joint muscle electromyographic and kinematic analyses were determined at pretest and posttest. ResultsAfter the intervention, the experimental group showed significantly greater improvements in balanced quadriceps and hamstring electromyographic coactivation and knee joint kinematics relative to the control group (P=.005). The GTG intervention decreased overactive hamstring activity (P=.018) and reciprocally increased quadriceps activity (P<.001). The knee joint kinematic analysis showed significant changes in the hemiparetic stroke group (P=.004). ConclusionsThis study demonstrates the effectiveness of the tubing gait condition to restore knee joint muscle imbalance and kinematics in individuals with hemiparetic stroke who present with an abnormal hyperextension knee gait.

Biomechanical analysis to characterize the impact of knee osteoarthritis on hip, knee, and ankle kinematics

Background: Numerous studies use a biomechanical assessment to evaluate joint function in knee pathologies such as osteoarthritis. However, most of them focus only on the knee and the consequences of the pathology on other lower limb joints are poorly documented. The objective of this study is to analyze the impact of knee osteoarthritis on ipsilateral hip and ankle joint during gait.Methods: Three-dimension (3D) angular kinematic patterns of the three joints were analyzed on 32 patients diagnosed with knee osteoarthritis (OA) and a control group of 15 asymptomatic subjects (AS). Kinematic data was captured during treadmill gait trials at a self-selected comfortable speed. Analysis of covariance (ANCOVA) was performed on selected points of interest from 3D kinematic patterns of the hip, knee and ankle joints to compare both groups. The significance level was set at p = .05.Results: Gait 3D kinematic gait patterns of OA patients revealed significant differences with those of AS subjects at the three joints.Conclusions: Results suggest that patients with knee osteoarthritis also present alterations in hip and ankle kinematic during gait that should be considered when tailoring conservative treatments.