[Purpose] The aims of this study were to evaluate the type and extent of error in the measurement of range of motion and to evaluate the effect of evaluators' proficiency level on measurement error. [Subjects and Methods] The participants were 45 university students, in different years of their physical therapy education, and 21 physical therapists, with up to three years of clinical experience in a general hospital. Range of motion of right knee flexion was measured using a universal goniometer. An electrogoniometer attached to the right knee and hidden from the view of the participants was used as the criterion to evaluate error in measurement using the universal goniometer. The type and magnitude of error were evaluated using the Bland-Altman method. [Results] Measurements with the universal goniometer were not influenced by systematic bias. The extent of random error in measurement decreased as the level of proficiency and clinical experience increased. [Conclusion] Measurements of range of motion obtained using a universal goniometer are influenced by random errors, with the extent of error being a factor of proficiency. Therefore, increasing the amount of practice would be an effective strategy for improving the accuracy of range of motion measurements.

The effects of static stretching are influenced by prescribed and applied loads of stretching. The prescribed load is calculated from the stretching duration and intensity, whereas the applied load is assessed from the force of static stretching exerted on the targeted muscle. No previous study has investigated the prescribed and applied loads of static stretching on the muscle-tendon unit stiffness simultaneously. Therefore, the purpose of the present study was to examine the acute effects of the prescribed and applied load of static stretching on the change in the muscle-tendon unit stiffness of the hamstrings by using different intensities and durations of static stretching. Twenty-three participants underwent static stretching at the intensity of high (50 seconds, 3 sets), moderate (60 seconds, 3 sets), and low (75 seconds, 3 sets), in random order. The parameters were the range of motion, passive torque, and muscle-tendon unit stiffness. These parameters were measured before stretching, between sets, and immediately after stretching by using a dynamometer machine. The static stretching load was calculated from the passive torque during static stretching. The muscle-tendon unit stiffness decreased in high- and moderate-intensity after 50 (p < 0.01, d = -0.73) and 180 seconds (p < 0.01, d = -1.10) of stretching respectively, but there was no change in low-intensity stretching for 225 seconds (p = 0.48, d = -0.18). There were significant correlations between the static stretching load and relative change in the muscle-tendon unit stiffness in moderate- (r = -0.64, p < 0.01) and low-intensity (r = -0.54, p < 0.01), but not in high-intensity (r = -0.16, p = 0.18). High-intensity static stretching was effective for a decrease in the muscle-tendon unit stiffness even when the prescribed load of static stretching was unified. The applied load of static stretching was an important factor in decreasing the muscle-tendon unit stiffness in low- and moderate-intensity static stretching, but not in high-intensity stretching.

[Purpose] To ensure that elderly individuals continue performing their activities of daily living, rehabilitation specialists have focused on several intervention programs, including programs that help maintain the functionality of digits. Grasping motion, including the ability to adjust grip, both spatially and temporally, is important for the elderly to continue independent living. The iWakka is a device used to measure the adjustability of grasping force and developed in Japan in 2012. This study aimed to evaluate the range of error of the iWakka, and verify its usefulness for evaluating adjustability of grasping force in elderly subjects. [Subjects and Methods] In 36 community-dwelling elderly subjects, over 65 years old, two readings of adjustability of grasping force, in the dominant and non-dominant hands were obtained using the iWakka, and a Bland-Altman analysis of the data was performed. [Results] The results demonstrated significant fixed bias in the dominant and non-dominant hands, but no significant proportional bias was observed. The limits of agreement were −2.8 to 4.4 g for dominant hand and −2.6 to 3.9 g for non-dominant hand. [Conclusion] Therefore, it is possible to measure the efficacy of interventions and detect declines in adjustability of grasping force using iWakka. Interventional programs can be designed for daily life based on the grasping force results shown by iWakka.

Dynamic stretching for more than 90 seconds is useful for improving muscle strength, although dynamic stretching for 30 seconds or less is commonly used in sports settings. The effects of dynamic stretching are influenced by the speed and amplitude of stretching, but no study examined these factors for 30 seconds of dynamic stretching. Therefore, the purpose of the present study was to examine the effects of speed (fast- or slow-speed) and amplitude (normal- or wide amplitude) of dynamic stretching for 30 seconds on the strength (peak torque during maximum isokinetic concentric contraction) and flexibility (range of motion, passive torque at maximum knee extension angle, and muscle-tendon unit stiffness) of the hamstrings. The passive torque and muscle-tendon unit stiffness reflect stretching tolerance and viscoelastic properties of the hamstrings, respectively. Fifteen healthy participants performed 4 types of 30 seconds of dynamic stretching. The muscle strength and flexibility were measured before and immediately after the dynamic stretching. The range of motion did not change after dynamic stretching at low speed and normal amplitude (p = 0.12, d = 0.59, 103.3%), but it was increased by other interventions (p < 0.01, d = 0.90-1.25, 104.5-110.1%). In all interventions, the passive torque increased (main effect for time, p < 0.01, d = 0.51 – 0.74, 111.0 – 126.9%), and muscle-tendon unit stiffness did not change. The muscle strength increased only after dynamic stretching at fast speed with normal amplitude (p < 0.01, d = 0.79, 107.1%). The results of the present study indicated that 30 seconds of dynamic stretching at fast speed and with normal amplitude can be beneficial for the measured parameters.