Masaki Katayose

Acute decrease in the stiffness of resting muscle belly due to static stretching.

The purpose of the study was to examine the acute effect of static stretching exercise on the resting stiffness of gastrocnemius muscle belly. Ten healthy young adults performed standing wall stretching in dorsiflexion for 1 min at a time and repeated five times. Before and after stretching, the shear modulus was measured in medial and lateral heads of the resting gastrocnemius muscle with ultrasound shear‐wave elastography. After the stretching, dorsiflexion range of motion (ROM) of the ankle joint increased (P < 0.01) by 3.9° and returned in 20 min. Immediately after stretching, shear modulus decreased (P < 0.01) by 14%, compared with before stretching across muscle heads. The decrease in shear modulus returned in 20 min after stretching. In the comparison group of 10 additional subjects, the standing intervention without stretching had no influence on these measures. There was a negative correlation between dorsiflexion ROM and shear modulus in either head before and after stretching. The results demonstrate the transient decreases in the stiffness of the resting gastrocnemius muscle belly and indicate that joint flexibility is greater in individuals with lower resting stiffness of the muscle belly.

Validity of fascicle length estimation in the vastus lateralis and vastus intermedius using ultrasonography

The purpose of this study was to determine the validity of fascicle length estimation in the vastus lateralis (VL) and vastus intermedius (VI) using ultrasonography. The fascicle lengths of the VL and VI muscles were measured directly (dFL) using calipers, and were estimated (estmFL) using ultrasonography, in 10 legs from five Thiels embalmed cadavers. To determine the validity of the estmFLs, FL was estimated using five previously published models and compared with dFL. The intraclass correlation coefficients (ICCs) of two of the five models were>0.75, indicating that these estimates were valid. Both of these models combined measurement of the length of the visible part of the fascicle with linear extrapolation of the length of the part of the fascicle that was not visible on the sonographic image. The ICCs and absolute% difference were best in models that used appropriate pennation angles. These results suggest that two of the five previously published models are valid for obtaining estmFL of the VL and VI using ultrasonography.

Analysis of Muscle Activity and Ankle Joint Movement During the Side-Hop Test

Yoshida, M, Taniguchi, K, and Katayose, M. Analysis of muscle activity and ankle joint movement during the side-hop test. J Strength Cond Res 25(8): 2255-2264, 2011—Functional performance tests (FPTs) that consist of movements, such as hopping, landing, and cutting, provide useful measurements. Although some tests have been established for kinematic studies of the knee joint, very few tests have been established for the ankle joint. To use the FPT as a test battery for patients with an ankle sprain, it is necessary to document typical patterns of muscle activation and range of motion (ROM) of the ankle joint during FPTs. Therefore, the purpose of this study was to investigate the pattern of the ROM of the ankle inversion/eversion and the muscle activity of the peroneus longus muscle (PL) and the tibial anterior muscle (TA) in normal subjects during the side-hop test. To emphasize the characteristics of ROM and electromyography (EMG) at each phase, the side-hop tests were divided into 4 phases: lateral-hop contact phase (LC), lateral-hop flight phase (LF), medial hop contact phase (MC), and medial hop flight phase (MF), and the ROM of ankle inversion/eversion, a peak angle of ankle inversion, and Integral EMG (IEMG) of PL and TA compared among 4 phases. Fifteen male subjects with no symptoms of ankle joint problems participated in this research. The ROM of ankle inversion/eversion during the side-hop test was 27 ± 3.8° (mean ± SD), and there was a significant difference in the ROM of ankle inversion/eversion among 4 phases (p < 0.05). The phase in which the widest ROM was presented was the MF. A peak angle of the ankle inversion at MC was significantly greater than at LC and MF (p <0.05). A peak angle of the ankle inversion at LF was significantly greater than at LC and MF. The PL remained contracting with 50-160% of maximal voluntary contraction (MVC). The IEMGs of PL in both the contact phases were significantly greater than in both the flight phases (p < 0.05). In addition, the PL activity at LC was significantly greater than at MC. The TA remained contracting at 50-80% of MVC through the side-hop test. The IEMG of TA at both the contact phases was significantly greater than at 2 flight phases. However, there was no significant difference between LC and MF. Results of this study could be useful as basic data when evaluating the validity of the side-hop test for patients with ankle sprain.

Three‐dimensional analysis of talar trochlea morphology

Three‐dimensional (3D) behavior of the talocrural joint is primarily determined by the articular surface morphology of the talar trochlea and tibiofibular mortise. However, morphological features of the anterior and posterior regions of the talar trochlea remain unclear. The objectives of this study were to evaluate anterior and posterior radii of the medial and lateral talar trochlea and to estimate subject‐specific kinematics of the talocrural joint. Fifty dry tali were scanned using computed tomography to create 3D bone models. Radii of curvature of the anterior and posterior region at both the medial and lateral trochlea were calculated. Orientations of the dorsiflexion and plantarflexion axis passing through the centers of the circles fitted to the anterior region of the medial and lateral trochlea and through the centers of the circles fitted to the posterior region of the medial and lateral trochlea were evaluated, respectively. The anterior radius of the medial trochlea was significantly smaller than that of the lateral trochlea by a mean of 7.8 mm (P < 0.001). The posterior radius of the medial trochlea was larger than that of lateral trochlea in 30 samples (60%) and vice versa in 20 samples (40%). Unilateral asymmetric shape of anterior trochlea would induce external rotation of the talus during ankle dorsiflexion, whereas bilateral asymmetric shape of posterior trochlea would induce opposite axial rotations among subjects during ankle plantarflexion, which would help the physical therapists to restore talocrural joint motions to ideal state for patients with ankle injuries. Clin. Anat. 29:1066–1074, 2016.

Three-dimensional analysis of talar trochlea morphology: Implications for subject-specific kinematics of the talocrural joint.

Three‐dimensional (3D) behavior of the talocrural joint is primarily determined by the articular surface morphology of the talar trochlea and tibiofibular mortise. However, morphological features of the anterior and posterior regions of the talar trochlea remain unclear. The objectives of this study were to evaluate anterior and posterior radii of the medial and lateral talar trochlea and to estimate subject‐specific kinematics of the talocrural joint. Fifty dry tali were scanned using computed tomography to create 3D bone models. Radii of curvature of the anterior and posterior region at both the medial and lateral trochlea were calculated. Orientations of the dorsiflexion and plantarflexion axis passing through the centers of the circles fitted to the anterior region of the medial and lateral trochlea and through the centers of the circles fitted to the posterior region of the medial and lateral trochlea were evaluated, respectively. The anterior radius of the medial trochlea was significantly smaller than that of the lateral trochlea by a mean of 7.8 mm (P < 0.001). The posterior radius of the medial trochlea was larger than that of lateral trochlea in 30 samples (60%) and vice versa in 20 samples (40%). Unilateral asymmetric shape of anterior trochlea would induce external rotation of the talus during ankle dorsiflexion, whereas bilateral asymmetric shape of posterior trochlea would induce opposite axial rotations among subjects during ankle plantarflexion, which would help the physical therapists to restore talocrural joint motions to ideal state for patients with ankle injuries. Clin. Anat. 29:1066–1074, 2016.

Effects of different movement directions on electromyography recorded from the shoulder muscles while passing the target positions

PURPOSE We compared electromyography (EMG) recorded from the shoulder joint muscles in the same position for different movement directions. METHODS Fifteen healthy subjects participated. They performed shoulder elevation from 0° to 120°, shoulder depression from 120° to 0°, shoulder horizontal adduction from -15° to 105°, and shoulder horizontal abduction from 105° to -15°. The target positions were 90° shoulder elevation in the 0°, 30°, 60°, and 90° planes (0°, 30°, 60°, and 90° positions). EMG signals were recorded from the supraspinatus (SSP) muscle by fine-wire electrodes. EMG signals from the infraspinatus (ISP), anterior deltoid, middle deltoid, and posterior deltoid muscles were recorded using active surface electrodes. RESULTS During elevation and horizontal abduction, the SSP showed significantly higher activity than that shown during depression and during horizontal adduction in the 0°, 30°, and 60° positions. During elevation, the ISP showed significantly higher activity than during depression and during horizontal adduction in the 90° position. During horizontal abduction, the ISP showed significantly higher activity than during depression in the 90° position. CONCLUSIONS When the movement tasks were performed in different movement directions at the same speed, each muscle showed characteristic activity.

Three-dimensional morphometric analysis of the talus: implication for variations in kinematics of the subtalar joint

PurposeThree-dimensional (3D) movement of the clinical subtalar joint (CSTJ) is primarily determined by the morphology of the articular surfaces of the talus. The purposes of this study were to assess the 3D orientation of the CSTJ facets of the talus and the talar head and to determine the tri-axial angular relationship.MethodsFifty dry tali were scanned using computed tomography to create a 3D bone model of the talus. The tri-axial angles of the anterior, middle, and posterior facets and the talar head were calculated. A correlation analysis between the angles of the posterior facet and the talar head was also performed.ResultsThe transverse angle at both the posterior facet and the talar head was significantly correlated with the sagittal angle (r = −0.441, p < 0.001; and r = −0.694, p < 0.001, respectively). The sagittal angle of the posterior facet was significantly correlated with that of the talar head (r = 0.478, p < 0.001).ConclusionsWhen the posterior facet of the talus and the talar head exhibits a greater downward and lesser medial orientation, a greater inversion/eversion at the CSTJ should be induced, while an opposite orientation should induce greater plantarflexion/dorsiflexion and medial/lateral rotation at the CSTJ. Our findings will be useful for planning rehabilitation programs and surgical interventions to correct the subtalar joint orientation in clinical settings.

Muscular responses appear to be associated with existence of kinesthetic perception during combination of tendon co-vibration and motor imagery

The afferent inputs from peripheral sensory receptors and efferent signals from the central nervous system that underlie intentional movement can contribute to kinesthetic perception. Previous studies have revealed that tendon vibration to wrist muscles elicits an excitatory response—known as the antagonist vibratory response—in muscles antagonistic to the vibrated muscles. Therefore, the present study aimed to further investigate the effect of tendon vibration combined with motor imagery on kinesthetic perception and muscular activation. Two vibrators were applied to the tendons of the left flexor carpi radialis and extensor carpi radialis. When the vibration frequency was the same between flexors and extensors, no participant perceived movement and no muscle activity was induced. When participants imagined flexing their wrists during tendon vibration, the velocity of perceptual flexion movement increased. Furthermore, muscle activity of the flexor increased only during motor imagery. These results demonstrate that kinesthetic perception can be induced during the combination of motor imagery and co-vibration, even with no experience of kinesthetic perception from an afferent input with co-vibration at the same frequency. Although motor responses were observed during combined co-vibration and motor imagery, no such motor responses were recorded during either co-vibration alone or motor imagery alone, suggesting that muscular responses during the combined condition are associated with kinesthetic perception. Thus, the present findings indicate that kinesthetic perception is influenced by the interaction between afferent input from muscle spindles and the efferent signals that underlie intentional movement. We propose that the physiological behavior resulting from kinesthetic perception affects the process of modifying agonist muscle activity, which will be investigated in a future study.

RELIABILITY AND VALIDITY STUDY OF A MEASUREMENT METHOD FOR THE GLENOID VERSION BY A 3-DIMENSIONAL BONE MODEL FROM 3.0 TESLA MRI

Objective The authors investigated reliability and validity of 3D-MRI bone model of scapula by comparing the Glenoid versions that were measured each in 3D-CT images and 3D-MRI images. Materials and Methods The scapula extraction DICOM data of MRI and CT was made to extract only a scapular domain. The scapula bone model was made with the scapula extraction DICOM data of MRI and CT. Glenoid version was measured on the scapula bone model. The mean and standard deviation of the Glenoid version was calculated by each imaging method (CT and MRI). Intraclass reliability of each imaging method (CT and MRI) and agreement between the two methods were evaluated. This was accomplished by calculating two separate measures of agreement: the intraclass correlation coefficient (ICC) and the Bland–Altman analysis. Results Glenoid version measured from the 3D-CT images averaged −0.679±3.797, with an ICC of 0.975. Glenoid version measured from the 3D-MRI images averaged −0.801±3.682, with an ICC of 0.980. Conclusions 3D-MRI bone model of scapula evaluated the reliability and the validity. 3D-MRI bone model of scapula was found to measure like 3D-CT bone model of scapula.

Kinematic Analysis of the Ankle Joint on the Side Hop Test in Subjects with Ankle Sprains

The side‐hop test (SHT) is useful functional performance test for ankle sprain. However, few research exists to investigate the relationship between the SHT and functional deficit in ankle. The objective of this study was to establish SHT as an evaluation criterion of functional deficits in ankle sprain. Twenty‐seven subjects with a history of ankle sprain participated. The time taken to perform SHT in the uninjured and injured limbs was measured. The angular displacements of the ankle joint were measured using the 3D motion analysis system. The muscle activities of the peroneus longus muscle (PL), tibialis anterior muscle (TA), and the medial and lateral gastrocnemius muscles (GM, GL) were measured using surface EMG. The time of SHT in the injured limb (9.22 ± 1.19 seconds) was significantly longer than that in the uninjured limb (8.71 ± 0.99 seconds). The range of the ankle inversion/eversion and dorsal flexion/plantar flexion in the injured limb was significantly greater than that in the uninjured limb. The injured limb showed a significant decrease in PL, TA, and GM integral EMG during SHT. Ankle motion and muscle activity caused the decline in SHT time in patients with injured limb.