Daily living activities present a diverse array of task and environmental constraints, highlighting the critical role of adapting gait initiation (GI) for an individual’s quality of life. This study investigated the effects of GI directions, obstacle negotiation, and leg dominance on anticipatory postural adjustments and stepping kinematics. Fourteen active, young, healthy individuals participated in GI across 4 directions—forward, medial 45°, lateral 45°, and lateral 90°—with variations in obstacle presence and leg dominance. Results revealed a consistent decreasing trend in maximum center of pressure displacement, anticipatory postural adjustment duration, step distance, and swing leg velocity with lateral shifts in GI directions, yet the step duration and swing leg heel trajectory were not affected by GI directions except in lateral 90° GI. Center of pressure displacements were intricately scaled to directional propulsive forces generation, and the stepping kinematics were influenced by the directional modifications in movements. With obstacles, modifications in anticipatory postural adjustment metrics and stepping kinematics reflected the obstacle clearance movements. The dominant leg GI exhibited longer step durations and greater movement variability in medial 45° GI. The current investigation of GI factors expands our existing understanding of GI dynamics and offers valuable insights applicable to fall prevention and gait rehabilitation strategies.
Browse
Directional-Specific Modulation of Postural Control and Stepping Kinematics in Multidirectional Gait Initiation
Kuanting Chen and Adam C. King
A Single Bout of On-Ice Training Leads to Increased Interlimb Asymmetry in Competitive Youth Hockey Athletes
Bryce D. Twible, Luca Ruggiero, Chris J. McNeil, and Brian H. Dalton
Interlimb asymmetry (ILA) refers to an anatomical or physiological imbalance between contralateral limbs, which can influence neuromuscular function. Investigating the influence of neuromuscular fatigue on ILA may be critical for optimizing training programs, injury rehabilitation, and sport-specific performance. The purpose of this study was to determine if a single bout of ice hockey-specific exercise creates or exacerbates lower-limb ILA. Before and after an on-ice training session, 33 youth ice-hockey athletes (14.9 [1.7] y; 11 females) performed 3 repetitions of a maximal vertical countermovement jump (CMJ), an eccentric hamstring contraction, and maximal isometric hip adduction and abduction contractions. Force- and power-related variables were analyzed to determine limb-specific neuromuscular function. The on-ice session reduced maximal isometric hip adduction (left: 7.3% [10.3%]; right: 9.5% [9.6%]) and abduction (left: 4.9% [6.9%]; right: 5.0% [8.1%]) force, but did not impair (P ≥ .10) CMJ performance (jump height, relative peak power, braking duration, and total duration). After the on-ice session, ILA was greater for CMJ propulsive impulse (6.3% [2.9%] vs 5.1% [2.6%]), CMJ braking rate of force development (19.3% [7.6%] vs 15.2% [6.4%]), and peak isometric hip adduction force (6.7% [5.5%] vs 6.1% [4.1%]). In conclusion, hockey-specific exercise leads to increased ILA for multiple force-related metrics, which may be a compensatory mechanism to maintain bilateral task performance when fatigued.
Vision Is Not Required to Elicit Balance Improvements From Beam Walking Practice
Natalie Richer, Steven M. Peterson, and Daniel P. Ferris
Background: Beam walking is a highly studied assessment of walking balance. Recent research has demonstrated that brief intermittent visual rotations and occlusions can increase the efficacy of beam walking practice on subsequent beam walking without visual perturbations. We sought to examine the influence of full vision removal during practice walking on a treadmill-mounted balance beam. Although visual disruptions improved performance of this task, we hypothesized that removing visual feedback completely would lead to less balance improvements than with normal vision due to the specificity of practice. Methods: Twenty healthy young adults trained to walk at a fixed speed on a treadmill-mounted balance beam for 30 min, either with, or without, normal vision. We compared their balance pre-, during, and posttraining by calculating their step-offs per minute and the percentage change in step-offs per minute. Results: Balance improved in both groups after training, with no significant difference in percentage change in step-offs between the normal vision and the no vision participants. On average, the no vision participants had twice as many step-offs per minute as the normal vision group during training. Conclusion: Although previous experiments show that intermittent visual perturbations led to large enhancements of the effectiveness of beam walking training, completely removing visual feedback did not alter training effectiveness compared with normal vision training. It is likely a result of sensory reweighting in the absence of vision, where a greater weight was placed on proprioceptive, cutaneous, and vestibular inputs.
Effect of External Work Magnitude on Mechanical Efficiency of Sledge Jumping
Keitaro Seki and Heikki Kyröläinen
The mechanical efficiency of human locomotion has been studied extensively. The mechanical efficiency of the whole body occasionally exceeds muscle efficiency during bouncing type gaits. It is thought to occur due to elasticity and stiffness of the tendinomuscular system and neuromuscular functions, especially stretch reflexes. In addition, the lower limb joint kinetics affect mechanical efficiency. We investigated the impact of varying external work on mechanical efficiency and lower limb kinetics during repeated sledge jumping. Fifteen male runners performed sledge jumping for 4 minutes at 3 different sledge inclinations. Lower limb kinematics, ground reaction forces, and expired gases were analyzed. Mechanical efficiency did not differ according to sledge inclination. Mechanical efficiency correlated positively with the positive mechanical work of the knee and hip joints and the negative contribution of the hip joints. Conversely, it correlated negatively with both the positive and negative contributions of the ankle joint. This may be attributable to the greater workload in this study versus previous studies. To achieve greater external work, producing more mechanical energy at the proximal joint and transferring it to the distal joint could be an effective strategy for improving mechanical efficiency because of the greater force-generating capability of distal joint muscles.
Evaluating the Impact of Seated Pilates on Functional Outcomes Among Those With Mild, Moderate, and Severe Multiple Sclerosis Impairment: A Pilot Feasibility Trial
Brynn Adamson, Keston G. Lindsay, Layla Almasri, Meghann Koppele Duffy, Stacy Kirkpatrick, and Manuel E. Hernandez
This pilot study assessed the feasibility and functional benefits of a twice-weekly, 12-week, virtual, seated, group-based Pilates program in persons with mild to severe multiple sclerosis (MS). Participants were randomized into either a Pilates-only group or a Pilates group, which also incorporated hip and shoulder-cuff activation exercises. Process, management, and scientific-feasibility metrics were analyzed descriptively. Functional outcomes, physical activity, and MS-related outcomes (impact, fatigue, and quality of life) were measured pre- and postintervention and analyzed using mixed-effects models, analysis of variance, and cluster analysis. Twenty-two participants completed baseline testing. Sixteen completed the intervention and postintervention testing. Collapsed across groups, analyses demonstrated improvements in the Timed 25-Foot Walk (36%), Timed Up-and-Go (13%), and the Berg Balance Scale (10%, statistically significant). Neither between-groups differences nor physical activity or MS outcome changes were significant. Participants reported high satisfaction. Findings suggest that virtual, seated Pilates is feasible and may confer balance benefits to individuals with MS.
Interlaboratory Study Toward Combining Gait Kinematics Data Sets of Long-Distance Runners
Reginaldo Kisho Fukuchi, Marcos Duarte, and Reed Ferber
The limited sample size in gait studies has hampered progress in the field. This challenge could be addressed through multicenter studies, thereby leveraging data sets from different laboratories. This study compared 3-dimensional lower-extremity running kinematics between the Biomechanics and Motor Control Laboratory, Federal University of ABC (Brazil), and the Running Injury Clinic, University of Calgary (Canada). Three-dimensional lower-extremity kinematics from 23 male runners were collected from each laboratory using comparable instrumentation and experimental procedures. The 3-dimensional hip, knee, and ankle angles were compared within and between centers using root-mean-square deviation. Two-sample t tests Statistical Parametric Mapping tested the hypothesis that the data from both laboratories were not different. The sagittal plane hip, knee, and ankle angles were similar between laboratories, while notable differences were observed for frontal (hip and ankle) and transverse (hip and knee) plane angles. The average interlaboratory root-mean-square deviation (2.6°) was lower than the intralaboratory root-mean-square deviation (Biomechanics and Motor Control = 4.8°, Running Injury Clinic = 5.6°), with the ankle transverse angle displaying the smallest, and the knee transverse angle displaying the largest variability. This study demonstrates the potential of combining gait kinematics data from different laboratories to increase sample size, but frontal and transverse plane data should be considered with caution.
Volume 40 (2024): Issue 4 (Aug 2024)
Comparing Sagittal-Plane Biomechanics of Drop Jump Landing in Athletes With and Without Knee Osteoarthritis 2-Year Post-Anterior Cruciate Ligament Reconstruction
Zakariya H. Nawasreh, Mohammad A. Yabroudi, Sharf M. Daradkeh, Sumayeh B. Abujaber, Adel S. Alsharei, and Khaldoon M. Bashaireh
The study aimed to determine differences in sagittal-plane joint biomechanics between athletes with and without knee osteoarthritis (OA) during drop vertical jump 2 years after anterior cruciate ligament reconstruction (ACLR). Forty-one athletes with ACLR completed motion analysis testing during drop vertical jump from 30 cm. Sagittal-plane peak joint angles and moments and joint contributions to total support moment (TSM) were calculated during first landing. Medial compartment knee OA of the reconstructed knee was evaluated using Kellgren–Lawrence scores (ACLR group: Kellgren–Lawrence <2; ACLR-OA group: Kellgren–Lawrence ≥2). The ACLR-OA group (n = 13) had higher hip and lower knee contributions in the surgical limb than the ACLR group and their nonsurgical limb. Further, the ACLR-OA group had higher peak hip extension moment than the ACLR group (P = .024). The ACLR-OA group had significantly lower peak knee extension and ankle plantar flexion moments and TSM (P ≤ .032) than ACLR group. The ACLR-OA group landed with increased hip extension moment, decreased knee extension and ankle plantar flexion moments and TSM, and decreased knee and increased hip contributions to TSM compared with ACLR group. The ACLR-OA group may have adopted movement patterns to decrease knee load and compensated by shifting the load to the hip. Clinicians may incorporate tailored rehabilitation programs that mitigate the decreased knee load to minimize the risk of knee OA after ACLR.
Dual-Task Cost Effects on Static Posture Control Parameters and Choice Reaction Time in Individuals With and Without Intellectual Disabilities
Danica Janicijevic, Saray Muñoz-López, Andrés Román Espinaco, and Carmen Gutiérrez-Cruz
This study aimed to evaluate the effect of age and intellectual disability (ID) on postural balance parameters, dual-task cost (DTC), and choice reaction time (CRT). Fifty-eight individuals with ID and 55 peers without ID performed a postural stance balance task under two conditions: a single task with eyes open and dual task involving an additional cognitive task (light sequence). Four postural balance parameters (total displacement, total sway area, mediolateral, and anteroposterior dispersion), cost of the dual task ([DTC%] = [(single-task performance − dual-task performance)/single-task performance] × 100), and CRT were recorded, calculated, and analyzed. All postural control parameters reflected poorerperformance during the dual-task condition, nevertheless, DTC was significantly higher only in individuals with ID and only for the total sway area, F(1, 111) = 5.039, p = .027, and mediolateral dispersion, F(1, 111) = 6.576, p = .012. CRT was longer in individuals with ID compared with the individuals without ID, F(1, 111) = 94.979, p ≤ .001, while age did not have a significant effect on the DTC nor on the CRT, F(1, 111) = 0.074, p = .786. In conclusion, an additional cognitive task during the postural balance task had a detrimental effect on various postural balance parameters, leading to increased DTC in terms of total sway area, mediolateral dispersion, and prolonged CRT in individuals with ID.
Effectiveness of Motor Imagery on Physical Function in Patients With Stroke: A Systematic Review
Jaruwan Prasomsri, Katsuya Sakai, and Yumi Ikeda
Over the past two decades, motor imagery (MI) has been used as a supplementary treatment approach to regain physical function in patients with stroke. However, the baseline treatment and the quality of study methodology for new treatment approaches have improved. This systematic review examined the evidence published in the past few decades on the effectiveness of MI on upper- and lower-extremity function and functional performance in patients with stroke. A total of 29 randomized controlled and crossover trials that compared MI with other interventions were analyzed. In addition, the outcomes were grouped into upper-, lower-extremity function, and functional performance for data analysis. More than half of the upper-extremity function studies reported improved performance in Fugl-Meyer assessment, Wolf motor function test, and box and block test in both acute and chronic stages. Lower-extremity function and functional performance were primarily investigated using Fugl-Meyer assessment, gait speed and parameters, activities of daily living, and balance ability. When considering only high-quality studies, six of 15 on upper extremity reported significant effects, whereas five of 15 reported nonsignificant effects. In addition, six of 14 studies on gait and balance reported significant effects. This systematic review suggests that both MI training and conventional rehabilitation programs effectively enhance upper limb functional abilities, including improvements in gait speed and balance, in individuals with acute and chronic stroke. Although the studies published during the past few decades showed heterogeneity in onset after stroke, research protocol, training intensity, and research methodology quality, none of them reported the long-term effects.
