A Biomechanical Foot-Worn Device Improves Total Knee Arthroplasty Outcomes

Background

Biomechanics after total knee arthroplasty (TKA) often remain abnormal and may lead to prolonged postoperative recovery. The purpose of this study is to assess a biomechanical therapy after TKA.

Prefrontal Cortex Activity and Gait in Parkinson's Disease With Cholinergic and Dopaminergic Therapy

Degradation of striatal dopamine in Parkinson's disease (PD) may initially be supplemented by increased cognitive control mediated by cholinergic mechanisms. Shift to cognitive control of walking can be quantified by prefrontal cortex activation. Levodopa improves certain aspects of gait and worsens others, and cholinergic augmentation influence on gait and prefrontal cortex activity remains unclear. This study examined dopaminergic and cholinergic influence on gait and prefrontal cortex activity while walking in PD. A single-site, randomized, double-blind crossover trial examined effects of levodopa and donepezil in PD. Twenty PD participants were randomized, and 19 completed the trial. Participants were randomized to either levodopa + donepezil (5 mg) or levodopa + placebo treatments, with 2 weeks with treatment and a 2-week washout. The primary outcome was change in prefrontal cortex activity while walking, and secondary outcomes were change in gait and dual-task performance and attention. Levodopa decreased prefrontal cortex activity compared with off medication (effect size, −0.51), whereas the addition of donepezil reversed this decrease. Gait speed and stride length under single- and dual-task conditions improved with combined donepezil and levodopa compared with off medication (effect size, 1 for gait speed and 0.75 for stride length). Dual-task reaction time was quicker with levodopa compared with off medication (effect size, −0.87), and accuracy improved with combined donepezil and levodopa (effect size, 0.47). Cholinergic therapy, specifically donepezil 5 mg/day for 2 weeks, can alter prefrontal cortex activity when walking and improve secondary cognitive task accuracy and gait in PD. Further studies will investigate whether higher prefrontal cortex activity while walking is associated with gait changes. © 2020 International Parkinson and Movement Disorder Society     

Genetic polymorphisms for BDNF,COMT, and APOE do not affect gait or ankle motor control in chronic stroke: A preliminary cross-sectional study

ABSTRACT

Background: Motor deficits after stroke are a primary cause of long-term disability. The extent of functional recovery may be influenced by genetic polymorphisms.

Objectives: Determine the effect of genetic polymorphisms for brain-derived neurotrophic factor (BDNF), catechol-O-methyltransferase (COMT), and apolipoprotein E (APOE) on walking speed, walking symmetry, and ankle motor control in individuals with chronic stroke.

Methods: 38 participants with chronic stroke were compared based upon genetic polymorphisms for BDNF (presence [MET group] or absence [VAL group] of a Met allele), COMT (presence [MET group] or absence [VAL group] of a Met allele), and APOE (presence [ε4+ group] of absence [ε4- group] of ε4 allele). Comfortable and maximal walking speed were measured with the 10-m walk test. Gait spatiotemporal symmetry was measured with the GAITRite electronic mat; symmetry ratios were calculated for step length, step time, swing time, and stance time. Ankle motor control was measured as the accuracy of performing an ankle tracking task.

Results: No significant differences were detected (p ≥ 0.11) between the BDNF, COMT, or APOE groups for any variables.

Conclusions: In these preliminary findings, genetic polymorphisms for BDNF, COMT, and APOE do not appear to affect walking speed, walking symmetry, or ankle motor performance in chronic stroke.     

Videofluoroscopic Evaluation of the Influence of a Gradually Reducing Femoral Radius on Joint Kinematics During Daily Activities in Total Knee Arthroplasty

BackgroundParadoxical anterior translation in midflexion is reduced in total knee arthroplasties (TKAs) with a gradually reducing femoral radius, when compared to a 2-radii design. This reduction has been shown in finite element model simulations, in vitro tests, intraoperatively, and recently also in vivo during a lunge and unloaded flexion-extension. However, TKA kinematics are task dependent and this reduction has not been tested for gait activities.MethodsThirty good outcome subjects (≥1 year postoperatively) with a unilateral cruciate-retaining TKA with a gradually reducing (n = 15) or dual (n = 15) femoral radius design were assessed during 5 complete cycles of level walking, stair descent (0.18-m steps), deep knee bend, and sitting down onto and standing up from a chair, using a moving fluoroscope (25 Hz, 1 ms shutter time). Kinematic data were extracted by 2D/3D image registration.ResultsTibiofemoral ranges of motion for flexion-extension, abduction-adduction, internal-external rotation, and anteroposterior (AP) translation were similar for both groups, whereas the pattern of AP translation-flexion-coupling differed. The subjects with the dual-radii design showed a sudden change in direction of AP translation around 30° of flexion, which was not present in the subjects with the gradually reducing femoral radius design.ConclusionThrough the unique ability of moving fluoroscopy, the present study confirmed that the gradually reducing femoral radii eliminated the paradoxical sudden anterior translation at 30° present in the dual-radii design in vivo during daily activities, including gait and stair descent.     

Analysis of terrain effects on the interfacial force distribution at the hand and forearm during crutch gait

Forces transferred to the upper body during crutch use can lead to both short-term and long-term injuries, including joint pain, crutch palsy, and over-use injuries. While this force transmission has been studied in controlled laboratory settings, it is unclear how these forces are affected by irregular terrains commonly encountered during community ambulation. The purpose of this study was to determine the effects of walking speed and uneven terrain on the load magnitude, distribution, and rate of loading at the human-crutch contact surfaces. Our results show that the rates of loading were significantly increased with higher walking speeds and while negotiating certain irregular terrains, despite there being no apparent effect on the peak force transmission, suggesting load rate may be a more appropriate metric for assessing terrain effects on crutch gait. Furthermore, irrespective of the type of terrain and walking condition, the largest compressive forces were found to reside in the carpal-tunnel region of the hand, and may therefore be a primary contributor to carpal-tunnel injury.     

The Feasibility and Validity of Body-Worn Sensors to Supplement Timed Walking Tests for Children with Neurological Conditions

Aims: The 10-meter walk test (10 mWT) and Timed Up and Go (TUG) are assessments of speed/time with a ceiling effect in pediatric populations. This study aimed to (1) determine whether collecting spatiotemporal data with inertial sensors (Mobility Lab, APDM Inc.) during these tests improves their discriminative validity, and (2) evaluate the clinical feasibility of Mobility Lab. Methods: Fifteen children with spina bifida (SB) or cerebral palsy (CP) (7.9 ± 3.1 years old) and fifteen age- and sex-matched typically-developing (TD) children completed the 10 mWT and TUG wearing Mobility Lab. Spatiotemporal data were compared between groups. Mobility Lab's potential to distinguish children with SB/CP from TD children was examined using conditional logistic regression. Feasibility was evaluated through participant adherence and a clinical utility scale. Results: For the 10 mWT, group differences (p < 0.01) were found in horizontal and frontal trunk range of motion, horizontal trunk velocity, and swing asymmetry. Children with SB/CP took significantly longer to turn during the TUG. These five variables together distinguished the two groups (p = 0.006). 78% of participants with SB/CP completed the testing protocol. Mobility Lab scored 4/10 on the clinical utility scale. Conclusions: Instrumenting the 10 mWT and TUG improves the tests’ ability to discriminate between children with SB/CP and TD children.     

Friedrich Trendelenburg: Historical background and significant medical contributions

Friedrich Trendelenburg's name is widely known today because it is associated with the Trendelenburg position. However, Trendelenburg made many other valuable contributions to the field of medicine, including a test, a gait, and a sign. A historical review of his life helps to elucidate the factors that contributed to his innovative approaches and techniques. Both Trendelenburg's mentors in his early years and the influences upon him throughout his professional career contributed to his development as a pioneer of surgery, anesthesia, and clinical diagnostics. Clin. Anat. 27:815–820, 2014. © 2014 Wiley Periodicals, Inc.