A comparison of two motion analysis systems for the measurement of two-dimensional rearfoot motion during walking

Two-dimensional video gait analysis: A systematic review of reliability, validity, and best practice considerations

BACKGROUND

Motion capture systems are widely used to quantify human gait. Two-dimensional (2D) video systems are simple to use, easily accessible, and affordable. However, their performance as compared to other systems (i.e. three-dimensional (3D) gait analysis) is not well established.

OBJECTIVES

This work provides a comprehensive review of design specifications and performance characteristics (validity and reliability) of two-dimensional motion capture systems.

STUDY DESIGN

Systematic review.

METHODS

A systematic literature search was conducted in three databases from 1990 to 2019 and identified 30 research articles that met the inclusion/exclusion criteria.

RESULTS

Reliability of measurements of two-dimensional video motion capture was found to vary greatly from poor to excellent. Results relating to validity were also highly variable. Comparisons between the studies were challenging due to differences in protocols, instrumentation, parameters assessed, and analyses performed.

CONCLUSIONS

Variability in performance could be attributed to study design, gait parameters being measured, and technical aspects. The latter includes camera specifications (i.e. resolution and frame rate), setup (i.e. camera position), and analysis software. Given the variability in performance, additional validation testing may be needed for specific applications involving clinical or research-based assessments, including specific patient populations, gait parameters, mobility tasks, and data collection protocols.

CLINICAL RELEVANCE

This review article provides guidance on the application of 2D video gait analysis in a clinical or research setting. While not suitable in all instances, 2D gait analysis has promise in specific applications. Recommendations are provided about the patient populations, gait parameters, mobility tasks, and data collection protocols.

Quantifying normal and parkinsonian gait features from home movies: Practical application of a deep learning-based 2D pose estimator

Objective

Gait movies recorded in daily clinical practice are usually not filmed with specific devices, which prevents neurologists benefitting from leveraging gait analysis technologies. Here we propose a novel unsupervised approach to quantifying gait features and to extract cadence from normal and parkinsonian gait movies recorded with a home video camera by applying OpenPose, a deep learning–based 2D-pose estimator that can obtain joint coordinates from pictures or videos recorded with a monocular camera.

Methods

Our proposed method consisted of two distinct phases: obtaining sequential gait features from movies by extracting body joint coordinates with OpenPose; and estimating cadence of periodic gait steps from the sequential gait features using the short-time pitch detection approach.

Results

The cadence estimation of gait in its coronal plane (frontally viewed gait) as is frequently filmed in the daily clinical setting was successfully conducted in normal gait movies using the short-time autocorrelation function (ST-ACF). In cases of parkinsonian gait with prominent freezing of gait and involuntary oscillations, using ACF-based statistical distance metrics, we quantified the periodicity of each gait sequence; this metric clearly corresponded with the subjects’ baseline disease statuses.

Conclusion

The proposed method allows us to analyze gait movies that have been underutilized to date in a completely data-driven manner, and might broaden the range of movies for which gait analyses can be conducted.

Tibial and calcaneal coupling during walking in those with chronic ankle instability

BACKGROUND

It is estimated that nearly 2 million individuals sprain their ankle each year in the US. A majority of these are recurrent injuries, which often results in chronic ankle instability. To better understand the cause of instability, previous research has looked at the coupling or coordination between leg and foot motion during locomotion.

RESEARCH QUESTION

Determine the coupling between the tibia and the calcaneus during the stance phase of walking in those without a history of ankle instability compared to those with either moderate or severe instability.

METHODS

Fifty-four individuals between the age of 18-30 years (15 males; 39 females) participated in this study. Each participant's history of ankle sprains and score on the Cumberland Ankle Instability survey was used to assign them to either a no, moderate or severe instability group. Electromagnetic sensors attached to the tibia and calcaneus recorded three-dimensional movement of their tibia and calcaneus during the stance phase of barefoot over ground walking. The kinematic data was referenced to the subject's standing position and time normalized to each subject's stance phase duration. The relative phase (RP) angle and RP variability between tibia internal/external rotation and calcaneal inversion/eversion motion was then calculated. A one-way analysis of variance test was used to determine if significant differences existed between the three groups of subjects on mean RP angle or variability. An alpha level of .05 was used to determine statistical significance.

RESULTS

A significant increase in RP angle and variability was found during the mid-stance phase of walking for those with severe ankle joint instability compared to those with moderate or no instability.

SIGNIFICANCE

The observed decreased coordination and increased coupling variability observed for those with severe ankle instability suggests either residual ligamentous damage, inadequate sensorimotor control, or both.

Clinical improvement in functional hallux limitus using a cut-out orthosis

BACKGROUND

Functional hallux limitus (FHL) has been implicated in the development of metatarsophalangeal joint osteoarthritis.

OBJECTIVES

To determine whether cut-out orthosis treatment increases plantarflexion of the first metatarsal by increasing its declination angle.

STUDY DESIGN

Cross-sectional study.

METHODS

A total of 46 female volunteers with an average age of 25.66 ± 5.70 years (range: 19-42 years) and FHL participated in the study. We assessed the degrees of movement of the first metatarsal and proximal phalanx bones at the first metatarsophalangeal joint without and while wearing the cut-out orthosis using the 3Space Fastrak® via sensors.

RESULTS

The movement of the plantarflexión declination angle of the first metatarsal bone was higher using the orthosis 29.84° ± 5.98° versus without orthosis 27.69° ± 5.91° (p < 0.031°). Use of sandals may have minimized the magnitude of movement changes associated with orthosis versus non-orthosis use.

CONCLUSION

The cut-out orthosis demonstrated a beneficial effect on non-fixed first metatarsophalangeal and metatarsal cuneiform joints affected by FHL, significantly increasing the declination of the metatarsal angle. Furthermore, use of the cut-out orthosis significantly reduced adduction movement of the first metatarsal bone in the transverse plane.

CLINICAL RELEVANCE

The cut-out orthosis demonstrated a beneficial effect on non-fixed first metatarsophalangeal and metatarsal cuneiform joints affected by FHL, significantly increasing the declination of the metatarsal angle. Furthermore, use of the cut-out orthosis significantly reduced adduction movement of the first metatarsal bone in the transverse plane.

Rearfoot eversion has indirect effects on plantar fascia tension by changing the amount of arch collapse

BACKGROUND

Rearfoot eversion motion and arch height are believed to contribute to increased tension on the plantar fascia and arch collapse during gait but the specifics of these relationships are not clear.

OBJECTIVE

To examine the relationships among static arch height, rearfoot eversion, dynamic arch height, and plantar fascia tension.

METHODS

28 healthy males participated. After static arch height was measured, the subjects were asked to run at 4.5m/s while frontal plane rearfoot motion, dynamic arch height, and ground reaction forces were collected. The relationships among variables were examined with bivariate correlations and path analysis.

RESULTS

The results indicated a high correlation between dynamic arch height and static arch height (r=0.642), plantar fascia tension (r=-0.797), and maximum rearfoot eversion motion during gait (r=-0.518). The path analysis model without the direct rearfoot eversion effect explained 81.2% of the variance in plantar fascia tension, while the model with the direct rearfoot eversion effect explained 82.1% of the variance in plantar fascia tension.

DISCUSSION

Including the indirect effect of maximum rearfoot eversion motion on plantar fascia tension through control of dynamic arch height is the model that best explains the interrelationships of these foot characteristics.

CONCLUSION

The amount of maximum rearfoot eversion motion itself is not a good predictor of plantar fascia tension, however, together with the arch height, maximum rearfoot eversion motion is a good predictor because it has a pronounced indirect effect on plantar fascia tension.

The influence of first ray mobility on forefoot plantar pressure and hindfoot kinematics during walking

BACKGROUND

Hypomobility and hypermobility of the first ray have been implicated in the literature as a primary cause of mechanical foot problems because of proposed obligatory and compensatory movements. Despite these theoretical links, research is sparse regarding the effect on kinematic and plantar pressure patterns as a result of altered first ray mobility. The purpose of this study was to determine whether hypomobility or hypermobility of the first ray alters hindfoot kinematics or the distribution of plantar pressures during walking.

METHODS

The magnitude of dorsal first ray mobility in 82 individuals was measured and then classified as being hypomobile, normal, or hypermobile. The plantar pressure under the first and second metatarsal heads, as well as hindfoot kinematics during walking, were then compared between the three categories of first ray mobility.

RESULTS

The results of this study indicate that those feet with a hypomobile first ray had significantly decreased plantar force and pressure values under the first metatarsal compared to the second metatarsal. In addition, feet with a hypomobile first ray showed significantly more hindfoot eversion compared to those with either normal or hypermobile first rays.

CONCLUSION

The results of this study do not support the common theoretical implications of altered mobility of the first ray related to plantar pressure and hindfoot kinematics.

Gait analysis after talonavicular joint fusion: 2 case reports

The purpose of this study was to analyze the alterations in frontal-plane hindfoot motion and in plantar pressure in 2 patients (3 feet) after talonavicular joint fusion. Three-dimensional movement of the hindfoot was recorded by using an electromagnetic motion analysis system. The results indicated that frontal-plane hindfoot motion of the operative foot was substantially reduced during the stance phase of walking. In addition, each patient's frontal-plane hindfoot angle while in the resting standing position was decreased and plantar pressure under the medial longitudinal arch was reduced after surgery.

Shank rotation: A measure of rearfoot motion during normal walking

Motion of the shank in the transverse plane is coupled with pronation and supination of the rearfoot, and so its motion relative to the foot can be used as an indicator of the pattern of motion in the rearfoot. Compared to the more commonly used assessment of motion in the frontal plane between the heel and the shank, motion of the shank in the transverse plane relative to the foot provides a more complete measure of the pattern of motion of the rearfoot because it reflects the motion in all three joints of the rearfoot (the ankle, subtalar joint and mid-tarsal joint) not solely the ankle and subtalar components. This work aimed to provide normative data for this alternative measure of rearfoot function. Data on angular displacement, angular velocity and angular acceleration were derived from motion-analysis conducted on 25 subjects. The results suggest a difference between the pattern of angular displacement indicated when motion of the shank relative to the foot is examined and the pattern of angular displacement indicated when motion in the frontal plane between the shank and heel is examined. Specifically, the former suggests that resupination of the rearfoot after rearfoot pronation during the initial period of gait, starts at the beginning of mid-stance, while the latter suggests resupination beginning in late mid-stance. Where comparisons were possible, data on the velocity and acceleration appeared reasonable and provide further parameters with which to investigate the role of motion in the rearfoot in the development of pathologic conditions and the effects of intervention on motion in the rearfoot.

A preliminary study determining the feasibility of electromagnetic tracking for kinematics at the ankle joint complex

OBJECTIVE

To determine the feasibility of using electromagnetic tracking (EMT) for quantifying three-dimensional kinematics at the ankle joint complex (AJC).

METHODS

AJC kinematics were recorded in 10 normal healthy adults, and 10 rheumatoid arthritis patients presenting with AJC instability and deformity who were undergoing footwear and orthotic intervention.

RESULTS

Kinematics in normal subjects had strong face validity, curve shape showing moderate (n=9), good (n=8) or excellent (n=4) agreement with data from seven published studies. The range of motion about the x-axis (15.2 degrees ) was similar to reference values (17.0 degrees ), but our technique underestimated rotations about the y- (8.1 degrees vs 14.0 degrees ) and z-axes (7.7 degrees vs 12.2 degrees ). In the rheumatoid arthritis pronated foot group, eversion and internal rotation during the stance phase of gait were between 2 and 5 times greater than for normal subjects. The use of a corrective foot orthosis in this group restored normal kinematics, reducing maximum eversion and internal rotation by 57 and 68%, respectively.

CONCLUSION

A new technique for measuring kinematics at the AJC is described. Based upon the findings of this pilot study, EMT may be useful for diagnosing AJC dysfunction and quantifying the mechanical efficacy of footwear and orthosis interventions.

Relative movement of the navicular bone during normal walking

The purpose of this study was to determine the pattern and magnitude of navicular bone (NB) movement during walking as well as the relationship between dynamic NB and rearfoot movement. The angle of rearfoot and displacement of the NB was recorded in 106 subjects using the 6D Research electromagnetic tracking system. The relative change in the height of the NB between foot flat and heel-off was 7.9 mm. The NB seems to undergo significant vertical as well as medial displacement during the stance phase of normal walking. This motion is also correlated with rearfoot motion during walking.