Does pathologically increased or decreased tibial torsion affect muscle activations during walking in typically developing adolescents?

A reduced capacity of plantar flexors and other muscles to extend the hip and knee during gait was shown in modelling studies when the tibial torsion angle is > 30° than normal. The aim of the current study was to determine if patients with increased or decreased tibial torsion show deviating muscle activations in knee and hip extensors in surface electromyography (EMG). Patients with CT confirmed increased tibial torsion (n = 19, ITT), decreased tibial torsion (n = 21, DTT) and age-matched healthy controls (n = 20) were included in this retrospective study. Additionally, kinematic and kinetic data were recorded during three-dimensional gait analysis. Surface EMG was recorded for vastus medialis and medial hamstrings. Statistical parametric mapping with a one-way ANOVA and post-hoc Bonferroni corrected two-sample t-tests were used to obtain differences in joint angles and moments. ITT and DTT showed an increased and decreased external foot progression angle, respectively. No additional muscle activations in vastus medialis and medial hamstrings were found in both patient groups compared to controls. DTT showed an increased hip flexion through parts of the gait cycle and both patient groups had a decreased knee extension moment in terminal stance. Our hypothesis of deviating muscle activation had to be rejected. It could be that in most orthopaedic patients the amount of exceeding tibial torsion is too low to cause substantial deviations in gait and muscle activation patterns.

Facilitatory rTMS over the Supplementary Motor Cortex Impedes Gait Performance in Parkinson Patients with Freezing of Gait.

Freezing of gait (FOG) in Parkinson's disease (PD) occurs frequently in situations with high environmental complexity. The supplementary motor cortex (SMC) is regarded as a major network node that exerts cortical input for motor control in these situations. We aimed at assessing the impact of single-session (excitatory) intermittent theta burst stimulation (iTBS) of the SMC on established walking during FOG provoking situations such as passing through narrow spaces and turning for directional changes. Twelve PD patients with FOG underwent two visits in the off-medication state with either iTBS or sham stimulation. At each visit, spatiotemporal gait parameters were measured during walking without obstacles and in FOG-provoking situations before and after stimulation. When patients passed through narrow spaces, decreased stride time along with increased stride length and walking speed (i.e., improved gait) was observed after both sham stimulation and iTBS. These effects, particularly on stride time, were attenuated by real iTBS. During turning, iTBS resulted in decreased stride time along with unchanged stride length, a constellation compatible with increased stepping frequency. The observed iTBS effects are regarded as relative gait deterioration. We conclude that iTBS over the SMC increases stepping frequency in PD patients with FOG, particularly in FOG provoking situations.

Altered activation and connectivity of the supplementary motor cortex at motor initiation in Parkinson's disease patients with freezing.

OBJECTIVE: Motor initiation failure is a key feature of freezing of gait (FOG) due to Parkinson's disease (PD). The supplementary motor cortex (SMC) plays a central role in its pathophysiology. We aimed at investigating SMC activation, connectivity and plasticity with regard to motor initiation in FOG. METHODS: Twelve patients with FOG and eleven without FOG underwent a multimodal electrophysiological evaluation of SMC functioning including the Bereitschaftspotential and movement-related desynchronisation of cortical beta oscillations. SMC plasticity was modulated by intermittent theta burst stimulation (iTBS) and its impact on gait initiation was assessed by a three-dimensional gait analysis. RESULTS: Prior to volitional movements the Bereitschaftspotential was smaller and beta power was less strongly attenuated over the SMC in patients with FOG compared to those without. Pre-motor coherence between the SMC and the primary motor cortex in the beta frequency range was also stronger in patients with FOG. iTBS resulted in a relative deterioration of gait initiation. CONCLUSIONS: Reduced activation of the SMC along with increased SMC connectivity in the beta frequency range hinder a flexible shift of the motor set as it is required for gait initiation. SIGNIFICANCE: Altered SMC functioning plays an important role for motor initiation failure in PD-related FOG.

How Do Scapulothoracic Kinematics During Shoulder Elevation Differ Between Adults With and Without Rotator Cuff Arthropathy?

BACKGROUND: Rotator cuff arthropathy with loss of active arm elevation can be successfully treated with nonanatomic reverse total shoulder arthroplasty to restore active elevation. Shoulder kinematics in this context predominantly focus on glenohumeral motion, neglecting scapular motion, although both substantially contribute to global shoulder motion. Because scapular kinematics are difficult to assess clinically and in the laboratory, they are not well understood and therefore are often reduced to glenohumeral models with a static scapula. QUESTIONS/PURPOSES: (1) Does the scapulohumeral rhythm (scapular rotation/glenohumeral elevation ratio) change during arm elevation? (2) Is there any scapular motion before arm elevation becomes clinically visible? (3) How do scapulothoracic kinematics during shoulder elevation differ between adults with and without rotator cuff arthropathy? METHODS: This was a comparative kinematics study of 20 young adult volunteers (reference group) without rotator cuff impairment (seven females, 13 males; mean age: 27 ± 3.5 years) and 20 patients (22 shoulders) with cuff tear arthropathy (10 females, 10 males; mean age: 74 ± 6.2 years). We used a three-dimensional (3-D) motion analysis system from Vicom with eight high-speed infrared cameras (frame rate 200 Hz) and 25 skin markers. Kinematics were studied for scapulothoracic and glenohumeral movements using the Upper Limb Evaluation in Movement Analysis (ULEMA) open-source model. The main motion studied was active arm elevation in the scapular plane. After data cleaning, modeling, and normalization, changes of scapulohumeral rhythm and scapular motion at the beginning of arm elevation were analyzed qualitatively, and statistical parametric mapping was applied to study the difference in scapulothoracic kinematics between adults with and without rotator cuff arthropathy. RESULTS: The scapular rhythm changes continuously during elevation. Whereas in people without rotator cuff arthropathy, a homogenous proportional relative angular contribution between 85° and 120° could be observed, this regular pattern was disturbed in patients with rotator cuff arthropathy. We observed medial scapular rotation before arm elevation became visible, followed by low lateral or even medial scapular rotation (approximately up to 25°) at the beginning of arm elevation. Patients with rotator cuff arthropathy exhibited more scapulothoracic motion between 50° and 93° of elevation than the reference group. CONCLUSIONS: Our study introduces a double-normalized data analysis that allows for a more detailed assessment of complex scapular kinematics in a noninvasive way. Scapulothoracic motion is more complex than previously reported, especially in patients with rotator cuff arthropathy. The scapulohumeral rhythm changes dynamically throughout arm elevation. There is counter-directed scapular rotation because of muscular engagement before clinically visible arm elevation. Compared with the homogenous shoulder kinematics in the reference group, patients with rotator cuff arthropathy show a different pattern with predominantly scapular motion in the range between 50° and 93° of arm elevation. CLINICAL RELEVANCE: The findings of this study suggest that there is a specific pattern of scapular motion during arm elevation in patients with rotator cuff arthropathy. Our study introduces a new noninvasive method that allows for simultaneous analysis of glenohumeral and scapular kinematics. This will enable to investigators explore whether active arm elevation and the physiological motion pattern can be restored after, for example, reverse total shoulder arthroplasty despite a nonanatomic prosthesis configuration.

Compensatory gait deviations in patients with increased outward tibial torsion pre and post tibial derotation osteotomy.

BACKGROUND: Tibial torsion describes the rotation between the proximal and distal joint axis along the shaft, which can be, as rotational deformity, pathologically increased or decreased. Some patients might increase hip internal rotation during walking to compensate increased outward tibial torsion. RESEARCH QUESTION: The aim of this study was to assess the effect of tibial derotation osteotomy on gait deviations in patients with increased outward tibial torsion. METHODS: Thirteen patients (13.5 ± 1.4 yrs, 22 limbs) with increased tibial torsion (CT confirmed 49.2 ± 4.8°) were analyzed pre and post tibial derotation osteotomy and compared with 17 typically developing children (TDC, 13.5 ± 2.3 yrs, 32 limbs). Kinematic and kinetic data were recorded. Subgroup analyses were performed whether patients showed compensatory hip internal rotation (Comp) or not (NoComp). Principal component (PC) analysis was used to achieve data transformation. A linear mixed model was used to estimate the main effect of PC-scores of retained PCs explaining 90% of the cumulative variance. RESULTS: Compensatory hip internal rotation (Comp, present in 45.5% of limbs analyzed) led to a lower external foot progression angle compared to patients without compensatory hip internal rotation (NoComp). In both patient groups foot progression angle was normalized after tibial derotation osteotomy. Post-operative NoComp had normalized frontal plane joint loadings, while Comp showed an increased hip and knee adduction moment. SIGNIFICANCE: Future studies should investigate if more time is needed for Comp to normalize gait patterns post-operative or if a pre and post-operative gait training might help. Otherwise the increased knee adduction moment might be clinically relevant due to previous studies reporting a possible association with knee osteoarthritis.

The impact of increased femoral antetorsion on gait deviations in healthy adolescents.

Increased femoral antetorsion leads to several gait deviations, and amongst others, an increased knee flexion was reported in mid and terminal stance. Therefore, the purpose of this retrospective study was to identify gait deviations caused by increased femoral antetorsion and to perform subgroup analyses based on sagittal knee kinematics. Patients with isolated, CT confirmed increased femoral antetorsion (n = 42) and age-matched typically developing children (TDC, n = 17) were included in this study. Patients were referred to gait analysis because of gait abnormalities going along with an increased femoral antetorsion ≥30°. Kinematic and kinetic data were recorded during 3D gait analysis and three valid gait cycles were analyzed. Principal component (PC) analysis was used to achieve data transformation. A linear mixed model was used to estimate the group effect of PC-scores of retained PCs explaining 90% of the cumulative variance. Group effects of PC-scores revealed that patients walked with more flexed hips and greater anterior pelvic tilt throughout the gait cycle. Knee flexion was increased in patients during mid and terminal stance. Increased frontal plane knee and hip joint moments were found for patients compared to TDC. Furthermore, dividing patients into two subgroups based on their sagittal knee kinematics showed that kinematic gait deviations were more pronounced in patients with higher femoral antetorsion, while deviations in joint moments were more pronounced in patients with lower femoral antetorsion. Increased femoral antetorsion showed alterations in all lower limb joints and may be not only a cosmetic problem. Therefore, 3D gait analysis should be used for clinical management and operative treatment should be considered depending on severity of gait deviations.

Reliability of scapular kinematics estimated with three-dimensional motion analysis during shoulder elevation and flexion.

BACKGROUND: Knowing the reliability of three-dimensional motion analysis to evaluate scapular kinematics during upper limb movements is essential to plan further research dedicated to understanding scapulothoracic joint movements relative to the global shoulder motion. RESEARCH QUESTION: The aim of this study was to assess the intra-subject as well as intra- and interrater reliability of scapulothoracic joint angles during shoulder elevation in scapular plane and shoulder flexion. METHODS: Twenty healthy participants (26.6 ± 3.5 years) were asked to perform maximum shoulder elevation in scapular plane as well as shoulder flexion. Reliability was assessed using the intraclass correlation coefficient (ICC) and its 95% confidence interval of scapular kinematics (rotation, tilting, pro-retraction) at each degree of global motion (shoulder elevation or shoulder flexion) between 0° to 150°. RESULTS: ICCs above 0.60 were accepted as good indicators for reliability. Intra-subject reliability was found to be very high (>0.9 for most part) for all scapulothoracic joint angles during both movements. Intra- and interrater reliability also showed good reliability being above 0.60 for the most part (except scapula tilting during shoulder elevation). Scapular kinematics showed low reliability during the respective first 10° and 20° of shoulder elevation and shoulder flexion. Furthermore, decreasing reliability was found above 120° of shoulder elevation or flexion. SIGNIFICANCE: This study generally showed good to high levels of reliability in the range of interest (20-120°) in evaluating scapula kinematics in healthy adults during shoulder elevation and flexion; these results are important for future research providing a better understanding of scapular kinematics.

Retrospective Evaluation of Changes in Gait Patterns in Children and Adolescents With Cerebral Palsy After Multilevel Surgery.

The purpose of this study was to retrospectively investigate changes in gait patterns after single-event multilevel surgery in children and adolescents with bilateral cerebral palsy. Three-dimensional instrumented pre- and postoperative gait data of 12 patients were compared to data of 12 healthy control subjects using principal component analysis to reduce the dimensionality of kinematic and kinetic gait data and detect gait differences. The differences between pre- and postoperative data and between postoperative data and data of control subjects were calculated using a linear mixed model. The results revealed 14 significant effects for pre- and postoperative waveforms and 11 significant effects for postoperative and control waveforms. Patients after single-event multilevel surgery walked with smaller internal foot progression angle throughout the gait cycle, lower knee flexion at initial swing, and earlier knee extension during terminal swing. Retained gait deviations included excessive pelvic tilt and internally rotated and flexed hips over the entire gait cycle. Contrary to our hypothesis, postoperative waveforms in the sagittal plane differed more from control waveforms than from preoperative waveforms. These results emphasize the importance of carefully planning further conservative therapy 2 years after single-event multilevel surgery.

Stair dimension affects knee kinematics and kinetics in patients with good outcome after TKA similarly as in healthy subjects.

Joint biomechanics during stair walking may contain important information on functional deficits in patients with orthopaedic conditions but depend on the stair dimension. The goal of this study was to compare knee kinematics and kinetics between patients with good outcome 2 years after total knee arthroplasty (TKA) and age-matched controls during stair ascent and descent at two different stair heights. Principal component analysis was used to detect differences in gait mechanics between 15 patients and 15 controls at different stair conditions. Linear mixed models showed differences in knee kinematic and kinetic patterns (in flexion/extension and abduction/adduction) between stair heights. The knee adduction angle was more affected by stair heights in stair ascending whereas knee adduction moment and knee power were more affected during stair descent. Some stair by height and subject effects were small but not significant. Overall, good outcome after TKA is reflected in close-to-normal knee biomechanics during stair walking. Specific stair configuration must be considered when comparing joint biomechanics between subject groups and studies. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1753-1761, 2016.

Gait deviations and compensations in pediatric patients with increased femoral torsion.

Coxa antetorta describes an abnormal torsion of the femur. It is commonly considered a cosmetic problem and is treated surgically only in severe cases and the presence of physical complaints. The purpose of this study was to identify deviations in gait kinematics and kinetics in pediatric patients caused by coxa antetorta and to categorize these deviations into primary and secondary deviations. We conducted a retrospective, cross-sectional three-dimensional (3D) gait analysis study to detect gait deviations in adolescents (n = 18; age range 10.5-17.5 years) with coxa antetorta compared to age-matched healthy control subjects (n = 17). Principal component (PC) analysis was used for data reduction. Linear mixed models applied to PC-scores were used to estimate the main effects within retained PCs followed by a post-hoc subgroup analysis. Patients walked with smaller external foot progression angle, greater knee adduction, more internally rotated and flexed hips and greater anterior pelvic tilt. Subgroup analysis revealed that-depending on knee alignment-patients had higher knee and hip adduction moments. These deviations in joint kinematics and kinetics may be associated with physical complaints and accelerated development of osteoarthritis. Assessment of gait deviations related to coxa antetorta using 3D gait analysis may be an additional tool in individual clinical decision-making.