The present study examined the effects of daily activities of the hands on finger motor function in older adults. Maximum tapping frequency with each finger during single-finger tapping and alternate movements of index–middle, middle–ring, and ring–little finger pairs during double-finger tapping were compared between older adults who used their hands actively in their daily lives and those who did not. The active participants had significantly faster tapping rates for the ring finger in the single-finger tapping and the middle–ring finger pair in the double-finger tapping than did the inactive participants. Thus, daily activity of the hands in older adults could be effective at preventing the loss of dynamic motor function in individual fingers, especially with greater difficulty in movement, resulting from the degeneration with age.
Tomoko Aoki and Koji Kadota
Karin Weman Josefsson
Sweden has adopted a somewhat different approach to handle the corona pandemic, which has been widely debated both on national and international levels. The Swedish model involves more individual responsibility and reliance on voluntary civic liability than law enforcement, while common measures in other countries are based on more controlling strategies, such as restrictive lockdowns, quarantines, closed borders, and mandatory behavior constraints. This commentary aims to give a brief overview of the foundations of the Swedish model as well as a discussion on how and why it has been adopted in the Swedish society based on Swedish legislations, culture, and traditions. Finally, perspectives on how the Swedish model could be connected to the tenets of self-determination theory will be discussed.
Richard Tahtinen, Hafrun Kristjansdottir, Daniel T. Olason, and Robert Morris
The aim of the study was to explore the prevalence of specific symptoms of depression in athletes and to test differences in the likelihood of athletes exhibiting these symptoms across age, sex, type of team sport, and level of competition. A sample of Icelandic male and female team sport athletes (N = 894, 18–42 years) was included in the study. Of the athletes exhibiting clinically significant depressive symptoms on the Patient Health Questionnaire-9, 37.5% did not exhibit core symptoms of depression. Compared with males, females were significantly more likely to exhibit depressed mood, feelings of worthlessness/guilt, and problems with sleep, fatigue, appetite, and concentration. Within males, differences were mostly related to neurovegetative aspects of depression (sleep and appetite), whereas in females, differences were related to cognitive/emotional aspects (e.g., depressed mood, guilt/worthlessness). The findings underline the importance of exploring specific symptoms of depression to provide a richer understanding of depressive symptomology in athletes.
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.
Justine J. Reel
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.
Svend Erik Mathiassen
Nathan Waite, John Goetschius, and Jakob D. Lauver
Runners experience repeated impact forces during training, and the culmination of these forces can contribute to overuse injuries. The purpose of this study was to compare peak vertical tibial acceleration (TA) in trained distance runners on 3 surface types (grass, asphalt, and concrete) and 3 grades (incline, decline, and level). During visit 1, subjects completed a 1-mile time trial to determine their pace for all running trials: 80% (5%) of the average time trial velocity. During visit 2, subjects were outfitted with a skin-mounted accelerometer and performed 18 separate running trials during which peak TA was assessed during the stance phase. Each subject ran 2 trials for each condition with 2 minutes of rest between trials. Peak TA was different between decline (8.04 [0.12] g) and incline running (7.31 [0.35] g; P = .020). On the level grade, peak TA was greater during grass (8.22 [1.22] g) compared with concrete (7.47 [1.65] g; P = .017). On the incline grade, grass (7.68 [1.44] g) resulted in higher peak TA than asphalt (6.99 [1.69] g; P = .030). These results suggest that under certain grade conditions grass may result in higher TA compared with either concrete or asphalt.