Amanda Young, Seán Healy, Lisa Silliman-French, and Ali Brian
To inform the development of scalable and sustainable fundamental motor skill interventions for children with Down syndrome, this study examined the feasibility and preliminary effectiveness of Project Skill Intervention Implemented by Parents (Project SKIP), a web-based, parent-mediated intervention intended to improve ball skills among children with Down syndrome. Twenty-four families enrolled in the study (including 13 boys and 11 girls; M age = 4.92). Fourteen children were assigned to an experimental group and participated in the 6-week intervention, and 10 children served as the inactive comparison group. The Test of Gross Motor Development-3 was administered preintervention and postintervention. In addition, parents of children in the experimental group completed a postintervention survey to assess their perceptions of Project SKIP. Following the intervention, there was a significant improvement in ball skills (p = .023, d = 0.86) for children in the experimental group, whereas the comparison group did not show significant improvement. Moreover, parents perceived Project SKIP to be feasible and effective; all parents reported being satisfied with their overall experience in the program, and 11 parents indicated that their child’s fundamental motor skills were positively influenced by the intervention. Engagement was high, with the majority of parents (n = 8, 57%) interacting with Project SKIP content three to four times a week.
Kerri A. Graber, Kari L. Loverro, Mark Baldwin, Erika Nelson-Wong, Joshua Tanor, and Cara L. Lewis
Pelvic drop is caused by decreased hip abductor muscle activity and is associated with lower-extremity injury. Hip abductor strengthening exercises are well established; however, no standard method exists to increase hip abductor activity during functional activities. The purpose of this research was to study the effects of walking with a unilateral weight. A total of 26 healthy adults walked on an instrumented treadmill with and without handheld weight (15%–20% body weight). Muscle activity, kinematic, and kinetic data were collected using surface electromyography, motion capture, and force plates, respectively. Average hip and trunk muscle activity, hip, pelvic, and trunk angles, and peak internal hip moments during stance were compared for each side (contralateral/ipsilateral to the weight) between conditions (unweighted/weighted) using a generalized linear model with generalized estimating equation correction. Interactions between condition and side were observed for muscle activity, frontal plane pelvic and trunk angles, and frontal plane hip moments (P ≤ .003). Compared with the unweighted condition, the weighted condition had higher hip abductor activity contralateral to the weight (P < .001), while no change was found ipsilateral to the weight (P ≥ .790). Similar changes were found for kinematic and kinetic variables. Walking with a unilateral weight may be a therapeutic option to increase functional hip abductor activity.
Dennis E. Dever, Kellen T. Krajewski, Camille C. Johnson, Katelyn F. Allison, Nizam U. Ahamed, Mita Lovalekar, Qi Mi, Shawn D. Flanagan, William J. Anderst, and Chris Connaboy
The objective was to examine the interactive effects of load magnitude and locomotion pattern on lower-extremity joint angles and intralimb coordination in recruit-aged women. Twelve women walked, ran, and forced marched at body weight and with loads of +25%, and +45% of body weight on an instrumented treadmill with infrared cameras. Joint angles were assessed in the sagittal plane. Intralimb coordination of the thigh–shank and shank–foot couple was assessed with continuous relative phase. Mean absolute relative phase (entire stride) and deviation phase (stance phase) were calculated from continuous relative phase. At heel strike, forced marching exhibited greater (P < .001) hip flexion, knee extension, and ankle plantar flexion compared with running. At mid-stance, knee flexion (P = .007) and ankle dorsiflexion (P = .04) increased with increased load magnitude for all locomotion patterns. Forced marching (P = .009) demonstrated a “stiff-legged” locomotion pattern compared with running, evidenced by the more in-phase mean absolute relative phase values. Running (P = .03) and walking (P = .003) had greater deviation phase than forced marching. Deviation phase increased for running (P = .03) and walking (P < .001) with increased load magnitude but not for forced marching. With loads of >25% of body weight, forced marching may increase risk of injury due to inhibited energy attenuation up the kinetic chain and lack of variability to disperse force across different supportive structures.
Kevin Alan Valenzuela, Songning Zhang, Lauren Elizabeth Schroeder, Joshua Trueblood Weinhandl, Jeffrey Reinbolt, Rebecca Zakrajsek, and Harold Earl Cates
Patient dissatisfaction following total knee replacement (TKR) procedures is likely influenced by both subjective and objective aspects. Increased pain and reduced performance on clinical tests have been shown in persons who are dissatisfied with the outcome of their surgery. However, it is unknown how overground walking kinematics and kinetics might differ in the dissatisfied versus satisfied patients following TKR surgery. This study compared the lower-extremity walking kinematics and kinetics of patients dissatisfied with their TKR to that of satisfied patients and healthy controls. Thirty nine subjects completed walking trials, including nine dissatisfied and 15 satisfied TKR patients and 15 healthy controls. A 2 × 3 repeated -measures analysis of variance was used to assess differences between groups and limbs (P < .05). Dissatisfied persons showed significantly reduced loading-response and push-off peak vertical ground reaction forces, flexion range of motion, loading-response extension moments, and loading-response abduction moments compared to the controls. Peak loading-response and push-off vertical ground reaction forces and flexion range of motion were reduced in the replaced limb of dissatisfied patients compared with their nonreplaced limb. Push-off plantar flexion moments were reduced in the dissatisfied patients compared with the satisfied and healthy controls. Dissatisfied patients also reported increased knee joint pain and reduced preferred gait speed. Moreover, dissatisfied patients experienced mechanical limb asymmetries not present in those satisfied with their surgery result. Thus, patients dissatisfied with their total knee replacement outcome were found to be experiencing significant negative physiological changes.
Iva Obrusnikova, Albert R. Cavalier, Richard R. Suminski, Ashleigh E. Blair, Cora J. Firkin, and Ashley M. Steinbrecher
Adults with an intellectual disability have significantly lower levels of fitness compared with the general population. This study examined the effects of a 13-week theoretically guided, community-based, multicomponent resistance training intervention, resistance training for empowerment, on muscular strength and independent functional performance in 24 adults with an intellectual disability, aged 18–44 years. Twelve participants were randomly allocated to an experimental group and 12 to an active control group. An analysis of covariance revealed that the experimental group had significantly greater increases (p < .05) on the chest press and leg press one-repetition maximum tests and the 6-min walk test from the baseline to postintervention compared with the control group. The experimental group correctly and independently performed a significantly greater number of steps of resistance training exercise tasks than the control group. Marginal significance and large effect sizes were found for the prone plank test and the stair climb test. The resistance training for empowerment was effective in promoting muscular strength and independent functional performance among adults with an intellectual disability.
Kentaro Kodama, Hideo Yamagiwa, and Kazuhiro Yasuda
As previous studies have suggested that bimanual coordination is important for slacklining, the authors questioned whether this important skill plays a role in the performance of a fundamental task of slacklining. To address this question, the authors compared single-leg standing on the slackline between novices and experts in terms of bimanual coordination dynamics within a dynamical systems framework using relative phase and recurrence quantification analysis measures. Five novices and five experts participated in the experiment. Participants were required to perform single-leg standing on a slackline. To collect motion data while slacklining, the authors used a 3D motion capture system and obtained time series data on the wrist position of both hands. The authors compared bimanual coordination dynamics between novices and experts. Although this preliminary study was limited in its sample size, the results suggest that experts tend to show a more antiphase coordination pattern than novices do and that they can more sustainably coordinate their hands compared with novices in terms of temporal structure in diagonal-related recurrence measures (i.e., maxline, mean line, and percentage determinism).
Geneviève N. Olivier, Christopher S. Walter, Serene S. Paul, Leland E. Dibble, and Sydney Y. Schaefer
Motor performance is classically described as improving nonlinearly with practice, demonstrating rapid improvements early in practice with stabilization later, which is commonly modeled by exponential decay functions. However, retrospective analyses of our previously collected data challenge this theoretical model of motor skill acquisition, suggesting that a majority of individual learners actually demonstrate patterns of motor improvement different from this classical model. A convenience sample of young adults, older adults, and people with Parkinson disease trained on the same functional upper-extremity task. When fitting three-parameter exponential decay functions to individual participant data, the authors found that only 13.3% of young adults, 40.9% of older adults, and 66.7% of adults with Parkinson disease demonstrated this “classical” skill acquisition pattern. Thus, the three-parameter exponential decay pattern may not well-represent individuals’ skill acquisition of complex motor tasks; instead, more individualized analysis methods may be warranted for advancing a theoretical understanding of motor skill acquisition.
Samar Ezzina, Clément Roume, Simon Pla, Hubert Blain, and Didier Delignières
The analysis of stride series revealed a loss of complexity in older people, which correlated with the falling propensity. A recent experiment evidenced an increase of walking complexity in older participants when they walked in close synchrony with a younger companion. Moreover, a prolonged experience of such synchronized walking yielded a persistent restoration of complexity. This result, however, was obtained with a unique healthy partner, and it could be related to a particular partner’s behavior. The authors’ aim was to replicate this important finding using a different healthy partner and to compare the results to those previously obtained. The authors successfully replicated the previous results: synchronization yielded an attraction of participants’ complexity toward that of their partner and a restoration of complexity that persisted in two posttests, 2 and 6 weeks after the end of the training sessions. This study shows that this complexity restoration protocol can be applied successfully with another partner, and allows us to conclude that it can be generalized.