Research indicates that increasing trunk flexion may optimize patellofemoral joint loading. However, this postural change could cause an excessive Achilles tendon force (ATF) and injury risk during movement. This study aimed to examine the effects of increasing trunk flexion during stair ascent on ATF, ankle biomechanics, and vertical ground reaction force in females. Twenty asymptomatic females (age: 23.4 [2.5] y; height: 1.6 [0.8] m; mass: 63.0 [12.2] kg) ascended stairs using their self-selected and flexed trunk postures. Compared with the self-selected trunk condition, decreases were observed for peak ATF (mean differences [MD] = 0.14 N/kg; 95% confidence interval [CI], 0.06 to 0.23; Cohen d = −1.2; P = .003), average rate of ATF development (MD = 0.25 N/kg/s; 95% CI, 0.07 to 0.43; Cohen d = −0.9; P = .010), ankle plantar flexion moment (MD = 0.08 N·m/kg; 95% CI, 0.03 to 0.13; Cohen d = −1.1; P = .005), and vertical ground reaction force (MD = 38.6 N/kg; 95% CI, 20.3 to 56.90; Cohen d = −1.8; P < .001). Increasing trunk flexion did not increase ATF. Instead, this postural change was associated with a decreased ATF rate and magnitude and may benefit individuals with painful Achilles tendinopathy.
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Lee T. Atkins, Michael Lowrey, Sarah Reagor, Kirsten Walker, and Dhalston Cage
Diego Augusto Santos Silva and Carolina Fernandes da Silva
Brazil is a country member of the Para Report Card, and Brazilian researchers have frequently published information on physical activity of children and adolescents. The current study aimed to analyze the policies for the promotion of adapted physical activity to Brazilian children and adolescents with disabilities. Official government information on adapted physical activity was analyzed from the official websites. Policies were analyzed based on the Para Report Card benchmarks, and after that we used the principles of SWOT (strengths, weaknesses, opportunities, and threats) to analyze the information. Adapted physical activity is not the main focus of any of the many policies to promote physical activity for children and adolescents. Based on the Para Report Card initiative, the score for this indicator in Brazil is D. Brazil needs to develop specific policies to promote physical activity adapted to the pediatric population with disabilities.
Kwok Ng, Sean Healy, Wesley O’Brien, Lauren Rodriguez, Marie Murphy, and Angela Carlin
For the first time, data on children and adolescents with disabilities in Ireland are reported based on the Active Healthy Kids Global Alliance Para Report Card methodology. The most recent data from the last 10 years were used in the grading process (A+ to F), and indicators with insufficient data were graded as incomplete. Of the 10 indicators from the Global Matrix Para Report Cards, grades were assigned to Overall Physical Activity (F), Organized Sport (D), Active Transport (D−), Sedentary Behaviors (D−), Family & Peers (C), School (C−), Community & Environment (B−), and Government (B). Irish disability sport organizations were invited to assess the research-led audit and provided commentary around the final grading. The contextual discussion of the grades is presented through the lens of strengths, weaknesses, opportunities, and threats with the purpose being to provide direction for the reduction of physical activity disparities among children with disabilities.
Tess M.R. Carswell, Brenton G. Hordacre, Marc D. Klimstra, and Joshua W. Giles
Research addressing lower limb amputee gait and prosthetic design often focuses on men, despite female lower limb amputees having different risk factors and lower success with their prosthetics overall. It is widely agreed that sex differences exist in able-bodied gait, but research analyzing sex differences in amputee gait is rare. This study compared male and female transtibial amputee gait to ascertain potential sex differences. Forty-five transtibial amputees were asked to walk at their self-selected speed, and spatiotemporal gait data were obtained. Both the mean and variability metric of parameters were analyzed for 10 male and 10 female participants. For all participants, amputated limbs had a shorter stance time, longer swing time, and larger step length. Females had a 10% shorter stance time and 26% larger normalized step and stride length than males. Female participants also walked over 20% faster than male participants. Finally, significant interactions were found in the mean and variability metric of stride velocity, indicating greater variability in women. These findings suggest that sex differences exist in transtibial amputee gait, offering possible explanations for the different comorbidities experienced by female lower limb amputees. These results have major implications for female amputees and for sex-specific research, rehabilitation, and prosthetic design.
Hannah Bennett, Robert Owens, and Tanya Prewitt-White
Mark L. Latash
Hangue Park, Alexander N. Klishko, Kyunggeune Oh, Celina Zhang, Gina Grenga, Kinsey R. Herrin, John F. Dalton IV, Robert S. Kistenberg, Michel A. Lemay, Mark Pitkin, Stephen P. DeWeerth, and Boris I. Prilutsky
Cutaneous feedback from feet is involved in regulation of muscle activity during locomotion, and the lack of this feedback results in motor deficits. We tested the hypothesis that locomotor changes caused by local unilateral anesthesia of paw pads in the cat could be reduced/reversed by electrical stimulation of cutaneous and proprioceptive afferents in the distal tibial nerve during stance. Several split-belt conditions were investigated in four adult female cats. In addition, we investigated the effects of similar distal tibial nerve stimulation on overground walking of one male cat that had a transtibial, bone-anchored prosthesis for 29 months and, thus, had no cutaneous/proprioceptive feedback from the foot. In all treadmill conditions, cats walked with intact cutaneous feedback (control), with right fore- and hindpaw pads anesthetized by lidocaine injections, and with a combination of anesthesia and electrical stimulation of the ipsilateral distal tibial nerve during the stance phase at 1.2× threshold of afferent activation. Electrical stimulation of the distal tibial nerve during the stance phase of walking with anesthetized ipsilateral paw pads reversed or significantly reduced the effects of paw pad anesthesia on several kinematic variables, including lateral center of mass shift, cycle and swing durations, and duty factor. We also found that stimulation of the residual distal tibial nerve in the prosthetic hindlimb often had different effects on kinematics compared with stimulation of the intact hindlimb with paw anesthetized. We suggest that stimulation of cutaneous and proprioceptive afferents in the distal tibial nerve provides functionally meaningful motion-dependent sensory feedback, and stimulation responses depend on limb conditions.
Adam J. Petway, Matthew J. Jordan, Scott Epsley, and Philip Anloague
A systematic search was performed of online databases for any Achilles tendon (AT) injuries occurring within the National Basketball Association (NBA). Video was obtained of injuries occurring during competition and downloaded for analysis in Dartfish. NBA athletes (n = 27) were identified with AT rupture over a 30-year period (1991–2021). Of the 27 NBA athletes found to have AT ruptures (mean age: 29.3 [3.3] y; average time in the NBA: 8.5 [3.8] y), 15 in-game videos were obtained for analysis. Noncontact rupture was presumed to have occurred in 12/13 cases. Eight of the 13 athletes had possession of the ball during time of injury. The ankle joint of the injured limb for all 13 athletes was in a dorsiflexed position during the time of injury (47.9° [6.5°]). All 13 athletes performed a false-step mechanism at time of injury where they initiated the movement by taking a rearward step posterior to their center of mass with the injured limb before translating forward. NBA basketball players that suffered AT ruptures appeared to present with a distinct sequence of events, including initiating a false step with ankle dorsiflexion of the injured limb at the time of injury.
Dayuan Xu, Jiwon Park, Jiseop Lee, Sungjune Lee, and Jaebum Park
Gravity provides critical information for the adjustment of body movement or manipulation of the handheld object. Indeed, the changes in gravity modify the mechanical constraints of prehensile actions, which may be accompanied by the changes in control strategies. The current study examined the effect of the gravitational force of a handheld object on the control strategies for subactions of multidigit prehension. A total of eight subjects performed prehensile tasks while grasping and lifting the handle by about 250 mm along the vertical direction. The experiment consisted of two conditions: lifting gravity-induced (1g) and weightless (0g) handheld objects. The weightless object condition was implemented utilizing a robot arm that produced a constant antigravitational force of the handle. The current analysis was limited to the two-dimensional grasping plane, and the notion of the virtual finger was employed to formulate the cause–effect chain of elemental variables during the prehensile action. The results of correlation analyses confirmed that decoupled organization of two subsets of mechanical variables was observed in both 1g and 0g conditions. While lifting the handle, the two subsets of variables were assumed to contribute to the grasping and rotational equilibrium, respectively. Notably, the normal forces of the thumb and virtual finger had strong positive correlations. In contrast, the normal forces had no significant relationship with the variables as to the moment of force. We conclude that the gravitational force had no detrimental effect on adjustments of the mechanical variables for the rotational action and its decoupling from the grasping equilibrium.
