Mediolateral Direction Research Articles

Acute effect of boing balance board on postural control in older adults

BACKGROUND: Balance training has demonstrated a positive effect on older adults. However, the specific types and durations of interventions needed to effectively address postural deficits in aging individuals remain important areas of study. It is crucial to impact their motor performance quickly to bring about changes in postural control. AIM: This study aims to investigate the effect of an acute motor intervention using a balance board called the "Boing" on postural control in elderly individuals. METHOD: Twenty senior women between the ages of 60 and 78 were divided into two groups: Intervention Group (IG, n=10) and Control Group (n=10). Both groups performed a pretest postural task on a force plate, including conditions with feet together, feet apart, and semi-tandem stance. Participants in the IG then underwent the motor intervention on the Boing balance board, which disturbed balance in the antero-posterior and medio-lateral directions, similar to the pretest conditions. After the intervention, a posttest was conducted for both groups using the same procedure as the pretest. One week later, a retention test was performed. Analysis of center of pressure (COP) was conducted, examining total displacement (DOT) and root mean square (RMS) in the antero-posterior and medio-lateral directions. RESULTS: A two-way repeated measures ANOVA revealed that during the posttest phase, there were significant differences between the groups in DOT and ML RMS specifically in the semi-tandem condition. The IG group exhibited lower values. CONCLUSION: The Boing balance board shows promise as a useful apparatus for improving postural control through acute motor intervention.

Evaluation of stability of the subjects with toe in gait due to increase in femoral head anteversion angle during quiet standing

Background: Toe in gait may be due to metatarsus adductus, increase in tibia torsion and femoral anteversion. It is controversial that it influences on standing stability or not. Therefore, the aim of this study was to evaluate the effects of toe in gait, due to increase in femoral head anteversion, on standing stability. Method: 11 subjects with toe in gait due to increase in femoral head anteversion were recruited in this study. There was also a control group matched with the toe in gait group. A Kistler force plate was used to evaluate stability of the subjects during quiet standing based on center of pressure (COP) sways. Results: The mean values of center of pressure (COP) excursion in anteroposterior direction was 14.41±4.66 and 23.41± 8.17 mm in normal and those with toe in gait, respectively (p-value <0.05). The difference between COP excursion in mediolateral direction in both group was not significant (p-value=0.085). There was a significant difference between velocity and path length of COP in both planes between the groups (p-value<0.05). Conclusion: Based on the results of this study, the subjects with toe in gait due to increase in femoral head anteversion are more unstable in quiet standing than normal subjects.

Electromyographic and Stabilometric Analysis of the Static and Dynamic "Standing Bird Dog" Exercise.

(1) Background: The "bird dog" exercise is considered one of the most effective therapeutic exercises for lumbopelvic rehabilitation and the prevention and treatment of low back pain. The "standing bird dog" (SBD) exercise, executed in a single-leg stance, constitutes a natural and challenging variation in the "bird dog"; nevertheless, this exercise has not yet been investigated. This study provides a stabilometric and electromyographic analysis of the SBD performed in static and dynamic conditions and in ipsilateral and contralateral variations; (2) Methods: A time-synchronized motion capture system, wireless electromyography sensors, and triaxial force platform were used to analyze the selected SBD exercises; (3) Results: In dynamic conditions, the gluteus maximum, multifidus, lumbar erector spinae, and gluteus medius reached a mean activation level higher than in the static condition, with peak activation levels of 80%, 60%, 55%, and a 45% maximum voluntary isometric contraction, respectively. In the static condition, balance control was more challenging in the mediolateral compared to the anteroposterior direction. In the dynamic condition, the balance challenge was higher in the anteroposterior direction and higher than the static condition in both directions; (4) Conclusions: The SBD was proved to be effective for strengthening the hip and lumbar extensor muscles and provided a powerful challenge to single-leg balance control in both mediolateral and anteroposterior directions.

Investigation of Static Balance Differences between Adolescents with Idiopathic Scoliosis and Healthy Age-matched Adolescents: A Cross-sectional Study

Background: The aim of this study was to compare postural control between Adolescents with Idiopathic Scoliosis (AIS) and healthy adolescents. Methods: In this cross-sectional study, 20 AIS adolescents with a right thoracic curvature between 10 and 45 degrees and 20 healthy adolescents were matched to compare postural control. Postural control assessments included Center of Pressure (COP) range and COP velocity in the Anteroposterior (AP) and Mediolateral (ML) directions, and the COP sway area in the standing position with opened eyes and closed eyes by the force plate. Results: This study showed that the postural control variables in AIS adolescents and healthy adolescents in terms of COP range, COP velocity, and COP sway area in standing positions with open and closed eyes were significantly different with those of AIS adolescents being worse than those of healthy adolescents (all p<0.001). The interaction between Group and Condition (eyes open and eyes closed) was not significant for all variables (all p>0.05). Conclusion: Differences in the postural control measures indicate postural instability in adolescents with AIS compared to healthy adolescents.

Where is tibial edema located in cases of osteomeniscal impingement?

To characterize the location of tibial edema related to meniscal degeneration with a flap displaced into the meniscotibial recess (osteomeniscal impingement) on magnetic resonance imaging (MRI). We evaluated 40 MRI examinations of patients submitted to surgery due to inferior displacement of a meniscal flap tear into the meniscotibial recess and peripheral bone edema. Tibial edema was quantified in the coronal and axial planes. On coronal MRI sequences, edema started in the tibial periphery and extended for a mean of 5.6 ± 1.4 mm, or 7.4 ± 2.1% of the tibial plateau. In the craniocaudal direction, the mean extension was 8.8 ± 2.9 mm. The mean ratio between the extent of craniocaudal and mediolateral edema was 1.6 ± 0.6. In the axial plane, the edema started in the medial periphery and extended for a mean of 6.2 ± 2.0 mm, or 8.2 ± 2.9% of the tibial plateau. In the anteroposterior measurement, the mean start and end of the edema was 21.4 ± 5.4 mm and 35.7 ± 5.7 mm, respectively, or 43.4 ± 10.2% and 72.8 ± 11.1% of the tibial plateau. Apparently, tibial edema resulting from osteomeniscal impingement always starts in the periphery of the meniscus. In the coronal plane, it appears to be more extensive in the craniocaudal direction than in the mediolateral direction. In the axial plane, we found it to extend, on average, approximately 6.2 mm in the mediolateral direction and to be most commonly located from the center to the posterior region of the medial tibial plateau.

Association between Objective and Subjective Sleep Parameters with Postural Control Responses among Brazilian Schoolteachers.

Objective To investigate the impact of sleep quality on postural control in teachers. Methods Cross-sectional study with 41 schoolteachers (mean age 45.7 ± 10.4 years). Sleep quality was assessed in two ways: objectively (through actigraphy), and subjectively (through the Pittsburgh Sleep Quality Index). Postural control was assessed in an upright posture during 3 trials of 30s (bipedal and semitandem stances in rigid and foam surfaces with eyes open) with a period of rest across trials, on a force platform, based in the center of pressure measurements in the anteroposterior and mediolateral directions. Results The prevalence of poor sleep quality in this study sample was 53.7% ( n = 22). No differences were found between Poor and Good sleep in the posturographic parameters (p > 0.05). Although, there was moderate correlation between postural control in the semitandem stance and subjective sleep efficiency for center of pressure area (rs = -0.424; p = 0.006) and amplitude in anteroposterior direction (rs = -0.386; p = 0.013). Discussion There is correlation between poor sleep quality and postural control in schoolteachers, as sleep efficiency decreases, postural sway increases. Poor sleep quality and postural control were investigated in other populations, but not in teachers. Several factors such as work overload, insufficient time for physical activities, among others, can contribute to a worse perception of sleep quality, as well as deterioration in postural control. Further studies with larger populations are needed to confirm these findings.

A Novel Orthognathic Surgery With a Half-Millimeter Accuracy for the Maxillary Positioning Using Prebent Plates and Computer-Aided Design and Manufacturing Osteotomy Guide.

This retrospective study aimed to assess the accuracy of prebent plates and computer-aided design and manufacturing osteotomy guide for orthognathic surgery. The prebent plates correspondent to the planning model were scanned with a 3-dimensional printed model for guide design and used for fixation. Forty-two patients who underwent bimaxillary orthognathic surgery using computer-aided design and manufacturing intermediate splint with the guide (guided group: 20 patients) or with conventional fixation under straight locking miniplates (SLMs) technique (SLM group: 20 patients) were analyzed. A deviation of the maxilla between the planned and postoperative positions was evaluated using computed tomography, which was taken 2 weeks before and 4 days after the surgery. The surgery time and the infraorbital nerve paranesthesia were also evaluated. The mean deviations in the mediolateral ( x ), anteroposterior ( y ), and vertical directions ( z ) were 0.25, 0.50, and 0.37mm, respectively, in the guided group, while that in the SLM group were 0.57, 0.52, and 0.82mm, respectively. There were significant differences in x and z coordinates ( P <0.001). No significant difference in the surgery duration and paranesthesia was seen, suggesting the present method offers a half-millimeter accuracy for the maxillary repositioning without increasing the risk of extending surgery duration and nerve complication.

Pain, dynamic postural control, mental health and impact of oral health in individuals with temporomandibular disorder: A cross-sectional study

IntroductionSome studies claim that functional changes in TMD affect the stomatognathic system (SS) and could contribute to the emergence of pain and changes in postural control. PurposeTo characterize and to compare pain, dynamic postural control (DPC), mental health and impact of oral health (QoL) in different types of temporomandibular disorders (TMD). MethodCross-sectional study with 116 participants evaluated by a validated TMD protocol and divided into three groups, muscle TMD (TMD-M, n = 32), joint TMD (TMD-J, n = 30) and muscle-joint TMD (TMD-MJ, n = 54).Chewing pain, DPC, anxiety, depression, sleep quality and impact of oral health on QoL were measured. One-way ANOVA, Kruskal-Wallis, Pearson's Chi-square test and eta-square effect size were used to data analysis. ResultsTMD-J showed less subjective pain than TMD-M (p = 0.014) and TMD-MJ (p = 0.021).TMD-J also presented greater height (p = 0.022) and body mass (p = 0.041) than the TMD-MJ and TMD-M, respectively. The DPC evaluation with sensory organization test 1 (SOT1, open eyes, platform and cabin fixed) in the medio-lateral direction (ML) was higher (p = 0.027) for TMD-J than TMD-M. TMD-MJ had a higher level of depression (p = 0.041) than TMD-J, and a greater impact of oral health on QoL (p = 0.035) than TMD-M. ConclusionMasticatory pain was lower in the TMD-J. There was a reduction in DPC in the ML of SOT1 in the TMD-J owing to the greater height of the patients in this group. The TMD-MJ had higher levels of depression and negative impact of oral health. In general, poor oral health reduces QoL in patients with TMD.

Smartphone Technology to Remotely Measure Postural Sway during Double- and Single-Leg Squats in Adults with Femoroacetabular Impingement and Those with No Hip Pain.

The COVID-19 pandemic has accelerated the demand for utilising telehealth as a major mode of healthcare delivery, with increasing interest in the use of tele-platforms for remote patient assessment. In this context, the use of smartphone technology to measure squat performance in people with and without femoroacetabular impingement (FAI) syndrome has not been reported yet. We developed a novel smartphone application, the TelePhysio app, which allows the clinician to remotely connect to the patient's device and measure their squat performance in real time using the smartphone inertial sensors. The aim of this study was to investigate the association and test-retest reliability of the TelePhysio app in measuring postural sway performance during a double-leg (DLS) and single-leg (SLS) squat task. In addition, the study investigated the ability of TelePhysio to detect differences in DLS and SLS performance between people with FAI and without hip pain. A total of 30 healthy (nfemales = 12) young adults and 10 adults (nfemales = 2) with diagnosed FAI syndrome participated in the study. Healthy participants performed DLS and SLS on force plates in our laboratory, and remotely in their homes using the TelePhysio smartphone application. Sway measurements were compared using the centre of pressure (CoP) and smartphone inertial sensor data. A total of 10 participants with FAI (nfemales = 2) performed the squat assessments remotely. Four sway measurements in each axis (x, y, and z) were computed from the TelePhysio inertial sensors: (1) average acceleration magnitude from the mean (aam), (2) root-mean-square acceleration (rms), (3) range acceleration (r), and (4) approximate entropy (apen), with lower values indicating that the movement is more regular, repetitive, and predictable. Differences in TelePhysio squat sway data were compared between DLS and SLS, and between healthy and FAI adults, using analysis of variance with significance set at 0.05. The TelePhysio aam measurements on the x- and y-axes had significant large correlations with the CoP measurements (r = 0.56 and r = 0.71, respectively). The TelePhysio aam measurements demonstrated moderate to substantial between-session reliability values of 0.73 (95% CI 0.62-0.81), 0.85 (95% CI 0.79-0.91), and 0.73 (95% CI 0.62-0.82) for aamx, aamy, and aamz, respectively. The DLS of the FAI participants showed significantly lower aam and apen values in the medio-lateral direction compared to the healthy DLS, healthy SLS, and FAI SLS groups (aam = 0.13, 0.19, 0.29, and 0.29, respectively; and apen = 0.33, 0.45, 0.52, and 0.48, respectively). In the anterior-posterior direction, healthy DLS showed significantly greater aam values compared to the healthy SLS, FAI DLS, and FAI SLS groups (1.26, 0.61, 0.68, and 0.35, respectively). The TelePhysio app is a valid and reliable method of measuring postural control during DLS and SLS tasks. The application is capable of distinguishing performance levels between DLS and SLS tasks, and between healthy and FAI young adults. The DLS task is sufficient to distinguish the level of performance between healthy and FAI adults. This study validates the use of smartphone technology as a tele-assessment clinical tool for remote squat assessment.

Control of center of mass during gait of stroke patients: Statistical parametric mapping analysis

BackgroundThe control of the center of mass is essential for a stable and efficient gait. Post-stroke patients present several impairments, which may compromise the control of the center of mass during gait in the sagittal and frontal planes. This study aimed to identify changes in the vertical and mediolateral behavior of the center of mass during the single stance phase of post-stroke patients using the statistical parametric mapping analysis. It also aimed to identify alterations in the center of mass trajectories regarding the motor recovery stages. MethodsSeventeen stroke patients and 11 neurologically intact individuals were analyzed. The statistical parametric mapping approach was used to identify changes in the center of mass trajectories between stroke and healthy groups. The trajectories of the center of mass of post-stroke individuals were compared according to their motor recovery status. FindingsA near-flat vertical trajectory of the center of mass was indenfitifed in the stroke group compared to their healthy counterparts, especially on the paretic side. The center of mass trajectories in both directions (vertical and mediolateral) presented substantial alteration at the end of the single stance phase in the stroke group. The trajectory of the center of mass of the stroke group was symmetrical in the mediolateral direction between the sides. The trajectories of the center of mass presented similar pattern irrespective of the motor recovery status. InterpretationThe statistical parametric mapping approach showed to be suitable for determining gait changes in post-stroke individuals, irrespective of their motor recovery stage.

Evaluation of Static and Dynamic Stability and Its Relationship With Fear of Falling in Patients With Mild to Moderate Knee Osteoarthritis

Objective Knee osteoarthritis is one of the most common musculoskeletal disorders affecting balance. It is also a risk factor for falling in older people. People with a history of falling, whether being injured or not, acquire a fear of potential falling, so they limit their functional activities, leading to decreased mobility, muscle weakness, and increased risk of falling in the future. Evaluating the relationship between balance and fear of falling in these patients can detect the disability mechanisms and falling and also help find more effective therapeutic methods for these patients. Some previous studies evaluated the stability of patients by clinical methods in static situations and related it to fear of falling. However, the walking stability of patients was not assessed by laboratory-based systems in previous studies. Therefore, we aimed to evaluate dynamic (during walking and based on the center of mass sways) and static stability (based on the center of pressure sways) and their relationship with falling risk in patients with knee osteoarthritis. Materials &amp; Methods This is a descriptive cross-sectional study. A group of 15 subjects with mild to moderate knee osteoarthritis with a Mean±SD age of 50±3.22 years and 15 normal subjects with comparable age, height, and weight participated in this study. The subjects’ standing stability was evaluated using a Kistler force plate based on mediolateral (ML) and anteroposterior (AP) displacements of the center of pressure. Also, the dynamic stability of the subjects was evaluated during walking and based on the center of mass-base of support relationship in AP and ML directions. Kinematic data were collected using a motion analysis system with 7 high-speed cameras and a Kistler force plate. To model the body segments, the output of Qualisys track manager software was exported to Visual 3D software. Fear of falling was assessed by the native version of the fall efficacy scale (FES-I). The normal distribution of data was checked by the Shapiro-Wilk test. The independent samples t-test was used to compare the stability of patients and normal subjects. The Pearson correlation coefficient was used to evaluate the relationships between static and dynamic stability parameters and fear of falling in patients with knee osteoarthritis. Results Patients with knee osteoarthritis had less stability during standing and walking than healthy subjects (P&lt;0.05). Moreover, based on the results of this study, there was a linear relationship between the center of body pressure (COP) excursions in the AP direction and the fear of falling scale. Still, it was not significant (r=0.416, P=0.123), and there was no correlation between the other COP parameters with FES (r=0, P&gt;0.05). The correlations between mean center of mass (COM) excursion in AP and ML directions and FES were 0.309 and -0.123, respectively; however, these correlations were also not statistically significant (P&gt;0.05). Conclusion Based on the results of this study, there is no significant relationship between static and dynamic stability of the patients with mild to moderate knee osteoarthritis (based on COP-COM variables) and the fall efficiency scale. So, it seems that to improve these patients’ functional abilities, and the therapists must focus on the other parameters that affect the falling, such as reducing pain, improving proprioception, and enhancing muscle strength. It is suggested that future studies include a more varied age range of elderly people and evaluate all contributing factors in falling of patients with knee osteoarthritis (such as pain, proprioception, vision, and muscle strength) and also evaluate the stability of patients with both laboratory-based and clinical tests.

Characteristics of uneven surface walking in stroke patients: Modification in biomechanical parameters and muscle activity

BackgroundStroke patients have difficulty walking in outdoor environments, including uneven surfaces, reducing their opportunities for social participation. Changes in stroke patients’ gait while walking on even surfaces have been reported; however, gait alterations on uneven surfaces remain unclear. Research questionTo what extent do biomechanical parameters and muscle activity during even and uneven surface walking differ between stroke patients and healthy people? MethodsTwenty stroke patients and 20 age-matched healthy people walked on a 6 m even and uneven surfaces. Data on gait speed, root mean square (RMS) of trunk acceleration as a measure of gait stability, maximum joint angle, average muscle activity, and muscle activity time were quantified using accelerometers attached to the trunk, video camera images, and electromyography of lower extremities. A two-factor mixed-model analysis of variance was used to test the effects of group, surface, and group × surface interactions. ResultsGait speed decreased (p < 0.001) on the uneven surface in stroke patients and healthy people. RMS showed an interaction (p < 0.001), and the post-hoc test revealed an increase in stroke patients in the mediolateral direction during the swing phase on the uneven surface. The hip extension angle during the stance phase showed an interaction (p = 0.023), and the post-hoc test revealed a decrease in stroke patients on the uneven surface. The soleus muscle activity time showed an interaction during the swing phase (p = 0.041), and the post-hoc test revealed an increase in stroke patients compared to healthy people only on the uneven surface. SignificanceWhile walking on an uneven surface, stroke patients showed decreased gait stability, decreased hip extension angle during stance phase, and increased ankle plantar flexor activity time during swing phase. These changes may result from impaired motor control and compensatory strategies used by stroke patients on uneven surfaces.

A modified two-dimensional sensory organization test that assesses both anteroposterior and mediolateral postural control.

The Sensory Organization Test (SOT) was designed to measure changes in postural control in response to unreliable visual and/or proprioceptive feedback. However, secondary to the manipulation of sensory cues in only the sagittal plane, the SOT is capable of only describing postural control in a single direction. The present study aimed to characterize postural responses to a modified SOT designed to concurrently challenge both anteroposterior and mediolateral postural control. Twenty-one healthy adult volunteers (30.6 ± 10.2 years) completed the standard anteroposterior one-dimensional (1D) SOT, in addition to a modified SOT with the support surface sway-referenced to both anteroposterior and mediolateral postural sway (two-dimensional, 2D). Our primary analysis concerned a comparison of mediolateral, as well as anteroposterior postural sway measured during the standard one-dimensional (i.e., pitch tilt) and the novel two-dimensional (i.e., roll and pitch tilt) sway-referenced paradigms. Here, postural sway was quantified by calculating the root mean square distance (RMSD) of the center of pressure (CoP) during each trial. Our data showed that the 2D sway-referenced conditions yielded a selective increase in mediolateral postural sway relative to the standard 1D conditions for both wide (η2 = 0.66) and narrow (η2 = 0.78) stance conditions, with anteroposterior postural sway being largely unaffected (η2 = 0.001 to 0.103, respectively). The ratio between mediolateral postural sway in the sway-referenced conditions and postural sway in the corresponding stable support surface conditions was greater for the 2D (2.99 to 6.26 times greater) compared to 1D paradigms (1.25 to 1.84 times greater), consistent with a superior degradation of viable proprioceptive feedback in the 2D paradigm. A modified 2D version of the SOT was shown to provide a greater challenge to mediolateral postural control relative to the standard 1D SOT protocol, putatively as a result of a superior capacity to degrade proprioceptive feedback in the mediolateral direction. Given these positive findings, future studies should investigate the clinical utility of this modified SOT as a means by which to better characterize sensory contributions to postural control in the presence of various sensorimotor pathologies, including vestibular hypofunction.

Center of Mass Estimation Using a Force Platform and Inertial Sensors for Balance Evaluation in Quiet Standing

Accurate estimation of the center of mass is necessary for evaluating balance control during quiet standing. However, no practical center of mass estimation method exists because of problems with estimation accuracy and theoretical validity in previous studies that used force platforms or inertial sensors. This study aimed to develop a method for estimating the center of mass displacement and velocity based on equations of motion describing the standing human body. This method uses a force platform under the feet and an inertial sensor on the head and is applicable when the support surface moves horizontally. We compared the center of mass estimation accuracy of the proposed method with those of other methods in previous studies using estimates from the optical motion capture system as the true value. The results indicate that the present method has high accuracy in quiet standing, ankle motion, hip motion, and support surface swaying in anteroposterior and mediolateral directions. The present method could help researchers and clinicians to develop more accurate and effective balance evaluation methods.

Adaptations in static balance due to unilateral restriction of the ankle joint: an observational study

Objective: Evaluating the static balance behavior in healthy women with unilateral ankle restriction. Methods: This observational study of static balance included 23 women and was conducted under three restriction conditions: no joint restriction of the right ankle (NJR), semi-rigid joint restriction using a Dilapé® anklet (SJR), and rigid joint restriction using adhesive tape (RJR). All participants underwent (1) passive range of motion (PRM) assessment of the ankle, (2) assessment of active range of motion (ARM) of the ankle, and (3) posturography instrumented by a force platform to collect the coordinates of the center of body pressure (CoP). Results: The joint restriction supports caused changes in ankle range of motion and generated effects on static balance, with significant changes in sway pattern (F80ap), anteroposterior signal regularity (SENtap), and mid-to-mid detachment amplitude. (Rangeml), in the average velocity (VMml) mediolateral direction, in addition to causing changes in the positioning of the CoP (CoPap_avg and CoPml_avg). Conclusion: Our results show that the use of unilateral restrictive supports modifies static posture due to mechanical restriction and proprioceptive stimulation. The anklet (SJR) was more effective than the tape (RJR) during the ARM, generating greater stability in the ankle joint and during the unipedal balance test, leading to a better correction to maintain posture.

The effects of proprioceptive weighting changes on posture control in patients with chronic low back pain: a cross-sectional study.

Patients with chronic low back pain (CLBP) exhibit changes in proprioceptive weighting and impaired postural control. This study aimed to investigate proprioceptive weighting changes in patients with CLBP and their influence on posture control. Sixteen patients with CLBP and 16 healthy controls were recruited. All participants completed the joint reposition test sense (JRS) and threshold to detect passive motion test (TTDPM). The absolute errors (AE) of the reposition and perception angles were recorded. Proprioceptive postural control was tested by applying vibrations to the triceps surae or lumbar paravertebral muscles while standing on a stable or unstable force plate. Sway length and sway velocity along the anteroposterior (AP) and mediolateral (ML) directions were assessed. Relative proprioceptive weighting (RPW) was used to evaluate the proprioception reweighting ability. Higher values indicated increased reliance on calf proprioception. There was no significant difference in age, gender, and BMI between subjects with and without CLBP. The AE and motion perception angle in the CLBP group were significantly higher than those in the control group (JRS of 15°: 2.50 (2.50) vs. 1.50 (1.42), JRS of 35°: 3.83 (3.75) vs. 1.67 (2.00), pJRS < 0.01; 1.92 (1.18) vs. 0.68 (0.52), pTTDPM < 0.001). The CLBP group demonstrated a significantly higher RPW value than the healthy controls on an unstable surface (0.58 ± 0.21 vs. 0.41 ± 0.26, p < 0.05). Under the condition of triceps surae vibration, the sway length (pstable < 0.05; punstable < 0.001), AP velocity (pstable < 0.01; punstable < 0.001) and ML velocity (punstable < 0.05) had significant group main effects. Moreover, when the triceps surae vibrated under the unstable surface, the differences during vibration and post vibration in sway length and AP velocity between the groups were significantly higher in the CLBP group than in the healthy group (p < 0.05). However, under the condition of lumbar paravertebral muscle vibration, no significant group main effect was observed. The patients with CLBP exhibited impaired dynamic postural control in response to disturbances, potentially linked to changes in proprioceptive weighting.

Quantification of phenobarbital-induced ataxia in dogs with idiopathic epilepsy.

Ataxia is a clinical sign seen in several neurological diseases and has been reported as an adverse effect of anti-seizure medication such as phenobarbital (PB). Efforts to objectify canine ataxia in order to provide appropriate treatment or monitor adverse effects of drugs remain limited. Automated quantitative gait analysis can be useful for the acquisition of objective data for the evaluation and monitoring of ataxia in dogs. The aim of this prospective clinical study was to examine the gait characteristics of dogs with PB induced ataxia and compare them with healthy dogs using a computer- and treadmill-based gait analysis system. Six healthy dogs and five dogs with idiopathic epilepsy (IE) with PB-induced ataxia underwent video- and computer-assisted gait analysis during slow walking (maximum speed of 0.7 m/s) on a treadmill with four ground reaction force plates (one plate per limb). Kinetic and spatio-temporal gait parameters of dogs' locomotion were analyzed, including individually calculated coefficients of variation. Dogs with IE treated with PB showed higher variability in spatio-temporal but not in kinetic gait parameters. Double support phase of gait cycles was increased on the cost of single support and swing phases. Body weight standardized ground reaction forces in vertical, craniocaudal, and mediolateral direction were severely affected by ataxia. Compensatory mechanisms in locomotion of dogs with PB-induced ataxia included spatio-temporal and kinetic gait characteristics, most likely in order to compensate imbalance caused by limb incoordination.

Quantitative assessment of plantar pressure patterns in relation to foot deformities in people with hereditary motor and sensory neuropathies

BackgroundHereditary motor and sensory neuropathies (HMSN), also known as Charcot-Marie-Tooth disease, are characterized by affected peripheral nerves. This often results in foot deformities that can be classified into four categories: (1) plantar flexed first metatarsal, neutral hindfoot, (2) plantar flexed first metatarsal, correctable hindfoot varus, (3) plantar flexed first metatarsal, uncorrectable hindfoot varus, and (4) hindfoot valgus. To improve management and for the evaluation of surgical interventions, a quantitative evaluation of foot function is required. The first aim of this study was to provide insight into plantar pressure of people with HMSN in relation to foot deformities. The second aim was to propose a quantitative outcome measure for the evaluation of surgical interventions based on plantar pressure.MethodsIn this historic cohort study, plantar pressure measurements of 52 people with HMSN and 586 healthy controls were evaluated. In addition to the evaluation of complete plantar pressure patterns, root mean square deviations (RMSD) of plantar pressure patterns from the mean plantar pressure pattern of healthy controls were calculated as a measure of abnormality. Furthermore, center of pressure trajectories were calculated to investigate temporal characteristics. Additionally, plantar pressure ratios of the lateral foot, toes, first metatarsal head, second/third metatarsal heads, fifth metatarsal head, and midfoot were calculated to measure overloading of foot areas.ResultsLarger RMSD values were found for all foot deformity categories compared to healthy controls (p < 0.001). Evaluation of the complete plantar pressure patterns revealed differences in plantar pressure between people with HMSN and healthy controls underneath the rearfoot, lateral foot, and second/third metatarsal heads. Center of pressure trajectories differed between people with HMSN and healthy controls in the medio-lateral and anterior-posterior direction. The plantar pressure ratios, and especially the fifth metatarsal head pressure ratio, differed between healthy controls and people with HMSN (p < 0.05) and between the four foot deformity categories (p < 0.05).ConclusionsSpatially and temporally distinct plantar pressure patterns were found for the four foot deformity categories in people with HMSN. We suggest to consider the RMSD in combination with the fifth metatarsal head pressure ratio as outcome measures for the evaluation of surgical interventions in people with HMSN.

Estimating 3D ground reaction forces in running using three inertial measurement units.

To understand the mechanisms causing running injuries, it is crucial to get insights into biomechanical loading in the runners' environment. Ground reaction forces (GRFs) describe the external forces on the body during running, however, measuring these forces is usually only possible in a gait laboratory. Previous studies show that it is possible to use inertial measurement units (IMUs) to estimate vertical forces, however, forces in anterior-posterior direction play an important role in the push-off. Furthermore, to perform an inverse dynamics approach, for modelling tissue specific loads, 3D GRFs are needed as input. Therefore, the goal of this work was to estimate 3D GRFs using three inertial measurement units. Twelve rear foot strike runners did nine trials at three different velocities (10, 12 and 14 km/h) and three stride frequencies (preferred and preferred ± 10%) on an instrumented treadmill. Then, data from IMUs placed on the pelvis and lower legs were used as input for artificial neural networks (ANNs) to estimate 3D GRFs. Additionally, estimated vertical GRF from a physical model was used as input to create a hybrid machine learning model. Using different splits in validation and training data, different ANNs were fitted and assembled into an ensemble model. Leave-one-subject-out cross-validation was used to validate the models. Performance of the machine learning, hybrid machine learning and a physical model were compared. The estimated vs. measured GRF for the hybrid model had a RMSE normalized over the full range of values of 10.8, 7.8 and 6.8% and a Pearson correlation coefficient of 0.58, 0.91, 0.97 for the mediolateral direction, posterior-anterior and vertical direction respectively. Performance for the three compared models was similar. The ensemble models showed higher model accuracy compared to the ensemble-members. This study is the first to estimate 3D GRF during continuous running from IMUs and shows that it is possible to estimate GRF in posterior-anterior and vertical direction, making it possible to estimate these forces in the outdoor setting. This step towards quantification of biomechanical load in the runners' environment is helpful to gain a better understanding of the development of running injuries.

Association of the Degree of Varus Thrust during Gait Assessed by an Inertial Measurement Unit with Patient-Reported Outcome Measures in Knee Osteoarthritis

This study aimed to assess the association between the degree of varus thrust (VT) assessed by an inertial measurement unit (IMU) and patient-reported outcome measures (PROMs) in patients with knee osteoarthritis. Seventy patients (mean age: 59.8 ± 8.6 years; women: n = 40) were instructed to walk on a treadmill with an IMU attached to the tibial tuberosity. For the index of VT during walking (VT-index), the swing-speed adjusted root mean square of acceleration in the mediolateral direction was calculated. As the PROMs, the Knee Injury and Osteoarthritis Outcome Score were used. Data on age, sex, body mass index, static alignment, central sensitization, and gait speed were collected as potential confounders. After adjusting for potential confounders, multiple linear regression analysis revealed that the VT-index was significantly associated with the pain score (standardized β = −0.295; p = 0.026), symptoms score (standardized β = −0.287; p = 0.026), and activities of the daily living score (standardized β = −0.256; p = 0.028). Our results indicated that larger VT values during gait are associated with worse PROMs, suggesting that an intervention to reduce VT might be an option for clinicians trying to improve PROMs.