External focus is a way to guide human movement based on outcome rather than execution, therefore all instructions are provided based on factors present in the environment. The aim of this review is to search information about the effects of external focus in the long jump task and to compare its outcomes with other learning methods. For the research, online database search engines such as PubMed, ScienceDirect, Embase, Cinahl, and Scopus were used from January 2010 to June 2020. About 41 articles were identified by searching the online databases, 12 were discarded because they were duplicates, 11 were excluded due to the content of the abstract, and finally, 5 were excluded after evaluating the content of the full text, leaving 13 articles to be included in this review. This review sought to summarize the findings in the literature on the use of external focus in the practice of long jump. The authors concluded that the external focus is a relevant approach and can be used as a tool for the learning process.
Geovani Messias da Silva and Maria Eduarda Crescencio Bezerra
Xiangyu Liu, Meiyu Zhou, Chenyun Dai, Wei Chen, and Xinming Ye
Surface electromyogram-based finger motion classification has shown its potential for prosthetic control. However, most current finger motion classification models are subject-specific, requiring calibration when applied to new subjects. Generalized subject-nonspecific models are essential for real-world applications. In this study, the authors developed a subject-nonspecific model based on motor unit (MU) voting. A high-density surface electromyogram was first decomposed into individual MUs. The features extracted from each MU were then fed into a random forest classifier to obtain the finger label (primary prediction). The final prediction was selected by voting for all primary predictions provided by the decomposed MUs. Experiments conducted on 14 subjects demonstrated that our method significantly outperformed traditional methods in the context of subject-nonspecific finger motion classification models.
Michele Verdonck, Jacquie Ripat, Peita-Maree Clark, Florin Oprescu, Marion Gray, Lisa Chaffey, and Bridie Kean
Wheelchair basketball (WCBB) often includes reverse integration (RI), defined as the inclusion of athletes without impairment in a sport traditionally aimed at athletes with an impairment. This study explored how RI in WCBB was understood by internal stakeholders. Data were gathered from athletes, coaches, and administrators at an Australian club competition and at a Canadian elite training center. Analysis of semistructured interviews with 29 participants led to the identification of eight themes. Collectively, the findings showed that RI was embedded within WCBB, RI was considered to be a way to advance the growth and improve the quality of WCBB as well as a way to increase awareness of WCBB and disability. There were some concerns that RI may not be equitable, as WCBB is a “disability sport.” Stakeholders’ perspectives on RI could provide useful information for sport policymakers, managers, administrators, sports organizations, and athletes interested in further developing WCBB.
Joshua Berger, Oliver Ludwig, Stephan Becker, Wolfgang Kemmler, and Michael Fröhlich
A 17-year-old male road cyclist with unspecific back pain and postural deficiency regarding the depth of the lumbar lordosis (flèche lombaire [fl]) and the upper body tilt (forward trunk tilt [tt]) absolved an 8-week whole-body electromyostimulation (WB-EMS) training to improve performance parameters and health issues. During WB-EMS, muscle groups all over the body are stimulated via external electrodes, thus creating an intensive training stimulus due to the electrically induced involuntary muscle contraction. The athlete’s posture (fl 2.2%, tt 64.3%) and back pain (54%) improved, and trunk strength increased (extension 15.5%, flexion 29.2%). This is the first WB-EMS study of a minor cyclist, suggesting positive effects of WB-EMS as a time-saving strength training method on health and strength parameters.
Daichi Tomita, Tadashi Suga, Hiromasa Ueno, Yuto Miyake, Takahiro Tanaka, Masafumi Terada, Mitsuo Otsuka, Akinori Nagano, and Tadao Isaka
This study examined the relationship between Achilles tendon (AT) length and 100-m sprint time in sprinters. The AT lengths at 3 different portions of the triceps surae muscle in 48 well-trained sprinters were measured using magnetic resonance imaging. The 3 AT lengths were calculated as the distance from the calcaneal tuberosity to the muscle–tendon junction of the soleus, gastrocnemius medialis, and gastrocnemius lateralis, respectively. The absolute 3 AT lengths did not correlate significantly with personal best 100-m sprint time (r = −.023 to .064, all Ps > .05). Furthermore, to minimize the differences in the leg length among participants, the 3 AT lengths were normalized to the shank length, and the relative 3 AT lengths did not correlate significantly with personal best 100-m sprint time (r = .023 to .102, all Ps > .05). Additionally, no significant correlations were observed between the absolute and relative (normalized to body mass) cross-sectional areas of the AT and personal best 100-m sprint time (r = .012 and .084, respectively, both Ps > .05). These findings suggest that the AT morphological variables, including the length, may not be related to superior 100-m sprint time in sprinters.
Aliaa M. Elabd, Salah-Eldin B. Rasslan, Haytham M Elhafez, Omar M. Elabd, Mohamed A. Behiry, and Ahmed I. Elerian
Although current lumbar stabilization exercises are beneficial for chronic mechanical low back pain, further research is recommended focusing on global spinal alignment normalization. This randomized, controlled, blinded trial was conducted to determine the effects of adding cervical posture correction to lumber stabilization on chronic mechanical low back pain. Fifty adult patients (24 males) with chronic mechanical low back pain and forward head posture received 12 weeks treatment of either both programs (group A) or lumbar stabilization (group B). The primary outcome was back pain. The secondary outcomes included the craniovertebral angle, Oswestry Disability Index, C7-S1 sagittal vertical axis, and sagittal intervertebral movements. The multivariate analysis of variance indicated a significant group-by-time interaction (P = .001, partial η 2 = .609). Pain, disability, C7-S1 sagittal vertical axis, and l2-l3 intervertebral rotation were reduced in group A more than B (P = .008, .001, .025, and .001). Craniovertebral angle was increased in A when compared to B (P = .001). However, there were no significant group-by-time interactions for other intervertebral movements. Within-group comparisons were significant for all outcomes except for craniovertebral angle within patients in the control group. Adding cervical posture correction with lumber stabilization for management of chronic low back pain seemed to have better effects than the application of a stabilization program only.
Justine J. Reel
Paul J. Read, Theodosia Palli, and Jon L. Oliver
Context: Single-leg hop tests are used to assess functional performance following anterior cruciate ligament (ACL) reconstruction. Recording 6-m timed hop scores using a stopwatch increases the potential for misclassification of patient status due to the number of error sources present. Objective: To examine the consistency of pass/fail (>90% limb symmetry index [LSI]) decisions in athletes tested at discharge following ACL reconstruction during the 6-m timed hop and the agreement between different human raters using a stopwatch and an electronic timing system. Setting: Clinic, rehabilitation. Participants: A total of 20 professional soccer players (age 24.6 [4.2] y; height 175.3 [10.2] cm; mass 73.6 [14.5] kg; 36 [10.5] wk following ACL reconstruction) volunteered to take part in this study. Main Outcome Measures: Two individual raters recorded each trial of the 6-m timed hop test on each limb with a stopwatch and an electronic timing system acted as the criterion measure. LSI scores were also computed with a pass score >90% LSI. Results: No significant differences were observed between limbs for any scoring method (P > .05). Mean differences indicated the electronic timing system was slower than both human raters (P < .05). Five participants failed the test (<90% LSI) but on each occasion this was only recorded by one method of rating. Kappa statistics showed no agreement in LSI scores across all 3 methods of scoring (κ = −.13) and no agreement when comparing the light gates to individual raters and rater 1 versus 2 (κ < 0). 95% limits of agreement in LSI scores recorded values of approximately ±20%. Conclusions: The 6-m timed hop test recorded using a stopwatch is not a valid measure to make clinical decisions following ACL reconstruction. Systematic bias between methods also suggests that a stopwatch and electronic timing system cannot be used interchangeably.
Corey A. Pew, Sarah A. Roelker, Glenn K. Klute, and Richard R. Neptune
The coupling between the residual limb and the lower-limb prosthesis is not rigid. As a result, external loading produces movement between the prosthesis and residual limb that can lead to undesirable soft-tissue shear stresses. As these stresses are difficult to measure, limb loading is commonly used as a surrogate. However, the relationship between limb loading and the displacements responsible for those stresses remains unknown. To better understand the limb motion within the socket, an inverse kinematic analysis was performed to estimate the motion between the socket and tibia for 10 individuals with a transtibial amputation performing walking and turning activities at 3 different speeds. The authors estimated the rotational stiffness of the limb-socket body to quantify the limb properties when coupled with the socket and highlight how this approach could help inform prosthetic prescriptions. Results showed that peak transverse displacement had a significant, linear relationship with peak transverse loading. Stiffness of the limb-socket body varied significantly between individuals, activities (walking and turning), and speeds. These results suggest that transverse limb loading can serve as a surrogate for residual-limb shear stress and that the setup of a prosthesis could be individually tailored using standard motion capture and inverse kinematic analyses.