Search

[Purpose] The purpose of this study was to investigate whether the recovery period of joint contractures differ between treatments with joint fixation with unweighting of the hind limbs and joint fixation alone. [Subjects and Methods] Twelve 10-week-old male Wistar rats were divided into a group with joint fixation of the right ankle joints in full plantar flexion for 1 week (F) and a group with joint fixation and hind limb suspension (FS). Thereafter, the rats were removed from the joint fixation and hind limb suspension for 2 weeks. The ankle dorsiflexion angles during the recovery process of the joint contractures were measured. [Results] The ankle dorsiflexion angles of the F group from the day joint fixation was removed to the seventh recovery day were significantly lower than the pre-experiment values. The ankle dorsiflexion angles of the FS group from the day joint fixation and hind limb suspension were removed to the 10th recovery day were significantly lower than the pre-experiment values. [Conclusion] We found that the period required for the recovery of joint contractures treated with joint fixation with unweighting of the hind limbs was longer than that with joint fixation alone.

[Purpose] The purpose of this study was to investigate the change in soleus extensibility from a joint contracture caused by a reduction in joint movement with unweighted lower limbs and to interpret the results to aid in the treatment of human joint contractures. [Subjects and Methods] The subjects of this study were twenty-one 10-weeks-old male Wistar rats. Twenty-one rats were divided into one control (C) and two experimental groups. The first experimental group included fixed right ankle joints in full plantar flexion (F). The second experimental group’s hind limbs were suspended and the right ankle joints were fixed in full plantar flexion (FS). The period of this study was one week. On the first and last day of this study, all of the rats’ ankle dorsiflexion angles were measured. On the last day of this study, all of the rats’ soleus extensibilities were measured. [Results] On the last day of this study, the ankle dorsiflexion angles and the soleus extensibility in the FS group were significantly more decreased than those of the F group. [Conclusion] It was shown that the skeletal muscle extensibility from joint contracture caused by reduction of joint movement with unweighted lower limbs was more markedly decreased than that from joint contracture caused by reduction of joint movement.

[Purpose] The purpose of this study was to determine the relationships of changes in pain and gait after ischemia reperfusion was induced by tourniquet in rats. [Subjects and Methods] The subjects were six ten-week-old male Wistar rats. Ischemia was induced in the left lower limbs of the experimental rats at a pressure of 300 mmHg for 90 minutes. Pain behavior evaluations were measured using the von Frey test in all the rats’ hind limbs. A consistently increasing plantar stimulus was applied until the rats exhibited an escape behavior. For the evaluation of gait, a two-dimensional motion analysis system was used to measure the distance from the calcaneus to the floor (DCF) and toe extension angle (TEA) during gait. The evaluations were performed in the normal state, 3 hours after ischemia-reperfusion, and daily until 7 days after ischemia-reperfusion. [Results] Compared with the normal state, the means of the pain threshold showed a significant decrease until 4 days after ischemia. In addition, both TEA and DCF continued to show a significant decrease at 7 days after ischemia as compared with the normal state. [Conclusion] This study revealed that hyperalgesia occurs after ischemia-reperfusion, and recovery of hyperalgesia occurred earlier than gait dysfunction recovery.

[Purpose] The purpose of this study was to examine whether an aerobic interval exercise using an eccentric contraction would result in skeletal muscular hypertrophy and augmentation of muscular strength in rats. [Subjects and Methods] Twenty-one female Wistar rats were used in this study. The rats were randomly divided into three groups. The control group performed no exercise. The aerobic endurance exercise group ran for 90 min. The aerobic interval exercise group ran for a total of 90 minutes in 5 minute bouts separated by 2 minute rest periods. The exercise groups ran on a downhill treadmill incline, once every three days, for a total of twenty sessions. [Results] The muscle wet weights, the muscle fiber cross-section minor axes, and the tetanus tension results of the aerobic endurance and aerobic interval exercise groups were significantly larger than those of the control group. [Conclusion] These results indicate that aerobic interval exercise may be an effective method of inducing hypertrophy and augmenting muscular strength in skeletal muscle.

[Purpose] The purpose of this study was to elucidate whether skin extensibility decreases when a contracture develops as a result of joint immobilization. [Subjects] This study was conducted on six female Wistar rats. [Methods] The rats were divided into two experimental groups. In the immobilized group, the right ankle joints were immobilized in complete plantar flexion by plaster casts for two weeks. In the control group, the left ankle joints had no intervention. On the final day, skin extensibility was determined from a length-tension curve by collecting skin from the posterior aspect of the ankle joint and using a tensile strength tester. [Results] Compared with the control group, the immobilized group showed a significant decrease in skin extensibility. [Conclusion] The results demonstrated that the extensibility of the skin itself decreases when joint contracture develops.

[Purpose] The purpose of this study was to investigate how a stretching torque affects muscular contractures. [Subjects] The subjects of this study were 48 male Wistar rats. [Methods] Subjects were divided into 4 groups as follows: Group 1 was the control; Group 2 had muscles in continuous fixation; Group 3 had muscles stretched in the direction of dorsiflexion by a spring balancer set at a torque of 0.3N for a period of 30 minutes after continuous fixation; and Group 4 had muscles stretched in the direction of dorsiflexion by a spring balancer set at a torque of 3.0N for a period of 30 minutes after continuous fixation. Joint fixation periods were for 2 and 4-weeks. Ankle joint range of motion and soleus flexibility were analyzed. [Results] For the 2-week joint fixation, soleus flexibility in Group 4 showed an increase compared with that of Group 3. For both fixation periods, range of motion in Group 4 showed an increase compared with that of Group 3. [Conclusion] For both fixation periods, stretching improved joint range of motion. In the 2-week joint fixation, soleus flexibility improved. However, soleus flexibility did not improve in the 4-week joint fixation.

[Purpose] The purpose of this study was to determine whether collagen fibers cause a difference in a contracture resulting from a combination of joint fixation and hindlimb unloading as compared to joint fixation only. [Subjects and Methods] The subjects of this study were 21 female Wistar rats divided into 4 groups as follows: Control Group (CON, n=7); Joint Fixation Group (JF, n=7), Hindlimb Unloading Group (HU, n=7), Joint Fixation Plus Hindlimb Unloading Group (JF+HU, n=7). This study was conducted for 1-week. Ankle joint range of motion and positive areas of collagen using fluorescent stain were analyzed. [Results] Ankle joint range of motion in JF + HU showed an increase compared to that of JF. Positive areas of Type I collagen in JF+HU showed an increase as compared with that of JF. [Conclusion] The results of this study suggested that the difference in a contracture caused by only joint immobilization and by a combination of joint immobilization and hindlimb unloading were significantly associated with Type I collagen.

Purpose: The purpose of this study was to examine the association of pain intensity and fear of pain with executive function in community-dwelling older adults with chronic pain. Methods: The community-dwelling older adults with chronic pain (pain duration≥ 3 months) were recruited. People whose Mini-Mental State Examination (MMSE) score was less than 24 point were excluded. Executive functionwas assessed by Digit Symbol Substitution Test (DSST). Subjective pain intensity was assessed by Numeric Rating Scale (NRS). Fear of pain was assessed by Tampa Scale for Kinesiophobia (TSK). Depression was measured using Geriatric Depression Scale (GDS). Pearson correlation test, Spearman rank correlation test and multiple regression analysis were used. In multiple regression analysis, DSST was taken as the main explanatory variable, whereas NRS/TSK was the outcome variable. Age, sex, years of education, the number of medication use, analgesic medication, MMSE, GDS and TSK/NRS were included as confounding factors. Results:Participantswere 105 community-dwelling older adults (78 women, mean age: 74.0± 6.6 years). In univariate analysis, DSST was associated with NRS and TSK significantly (NRS;ρ =−0.27, p< 0.001, TSK; r=−0.24, p< 0.05). In multivariate analysis, after adjustment, NRS and TSK was still associated with DSST (NRS; adjusted β =−0.30, p< 0.05, adjusted R2 = 0.16, TSK; adjusted β =−0.25, p< 0.05, adjusted R2 = 0.26). Conclusion(s): Pain intensity and fear of pain was associated with executive function in community-dwelling older adults with chronic pain. Implications: In order to reduce pain intensity or to improve fear of pain in community dwelling older adults with chronic pain, it would be efficacious to approach to executive function.

Methods: Twenty acute stroke patients were randomized into rTMS group or sham group. Patients received 5 daily sessions of 1Hz rTMS or sham rTMS over the intact motor cortex. For recording MRCP, patients performed self-paced wrist dorsiflexion of affected limb before and after rTMS sessions. Electrodes were placed at Fz, FC3, FCz, FC4, C3, Cz, C4 and Pz according to the international 10–20 system. MRCPwas divided into 3 components of Bereitschaft potential (BP), negative slope (NS’) and motor potential (MP). For behavioral testing, patients performed the upper extremity Fugl-Meyer Assessment (FMA), pegboard test, and grip strength before and after rTMS sessions. TheMRCP data and behavioral data were subjected to repeated measures analysis of variance (ANOVA) using time (pre-rTMS and post-rTMS) as within-subject factors and group (rTMS group and sham group) as a between-subject factor. Pearson correlation coefficient or Spearman’s rank correlation coefficient was used to assess associations between MRCP and motor function data. Results: MRCP showed a significant increase of MP amplitude at C and FC sites in affected hemisphere after rTMS to the contralesional motor cortex for five days (Ps < 0.05). At the same time, there were increases of NS’ amplitude at C and FC sites in affected hemisphere and at Cz site (Ps < 0.05). The behavioral data showed significant improvement of FMA and PPT in the rTMS group compared to the sham group (Ps < 0.02). The improvement of FMA for upper limbmotor functionwas correlatedwith the increase of MRCPamplitude recorded over the ipsilesionalmotor cortex. Conclusion(s): Low-frequency rTMS to contralesional motor cortex promoted motor functional recovery of upper extremity for acute stroke patients, and this improvement was associated with enhanced movement-related electrophysiological activity of affected motor cortex possibly through suppression of transcallosal inhibition. Implications: Low-frequency rTMS to non-affected hemisphere may be promising intervention for motor recovery even in acute stroke patients with hemiparesis.