Isokinetic knee strength and proprioception before and after anterior cruciate ligament reconstruction: A comparison between home-based and supervised rehabilitation.

BACKGROUND: Rehabilitation after anterior cruciate ligament (ACL) reconstruction focuses on restoring knee deficiencies and function. However, the extent of the clinician's direct supervision that is required to recover knee function is unknown. OBJECTIVE: To investigate differences in isokinetic knee strength improvement, endurance, and proprioception between home-based (HBR) and supervised rehabilitation (SR). METHODS: Thirty participants were randomly allocated to each group after reconstruction. Isokinetic knee strength and proprioception were measured using the Biodex multi-joint and stability systems, respectively, before and after intervention. RESULTS: The SR group showed a significant improvement from baseline, but not the HBR group (SR group, from 1.94 ± 1.44 to 1.02 ± 0.92, p< 0.05; HBR group, from 1.69 ± 0.88 to 1.61 ± 0.90, p> 0.05). There was a significant effect of exercise type on proprioception scores after controlling for pretest values (p< 0.05). No significant difference in isokinetic knee strength was observed between the groups. CONCLUSIONS: HBR recovered knee strength as effectively as the SR, but SR was more effective than HBR for the recovery of proprioception and functional knee movement. This result indicates that guidance from health professionals play an important role in enhancing proprioception for patients following ACL reconstruction.

Effects of assisted sit-up exercise compared to core stabilization exercise on patients with non-specific low back pain: A randomized controlled trial.

BACKGROUND: Traditional sit-up exercise is a simple method to strengthen core muscles. However, it can increase the potential of lumbar spine injury during the bending process. OBJECTIVE: To evaluate the effect of assisted sit-up exercise (SUE) using a new training device, HubEX-LEX®, on strengthening core muscles and improving non-specific low back pain (NSLBP) compared to conventional core stabilization exercise (CSE). METHODS: Subjects with chronic NSLBP were randomly divided into two groups: SUE (n= 18) or CSE (n= 18). They participated in 12 sessions of the exercise program. Before and after the training, thickness and activity of core muscles were measured using ultrasonogram and surface electromyography respectively. Pain and disability were assessed using two questionnaires. RESULTS: Thickness ratios (contracted/rest) of rectus abdominis and external oblique in the SUE group and those of transversus abdominis in the CSE group showed statistically significant difference between before and after exercise (p< 0.05). The ratio of activation of internal oblique relative to rectus abdominis and all measurements for pain and disability showed statistically significant improvement in both groups (p< 0.05). CONCLUSIONS: Assisted SUE using new training device can be an effective therapeutic exercise to strengthen dynamic abdominal muscles and improve core muscle activation pattern in NSLBP patients.

The role of tactile sensation in online and offline hierarchical control of multi-finger force synergy.

The hand, one of the most versatile but mechanically redundant parts of the human body, must overcome imperfect motor commands and inherent noise in both the sensory and motor systems in order to produce desired motor actions. For example, it is nearly impossible to produce a perfectly consistent note during a single violin stroke or to produce the exact same note over multiple strokes, which we denote online and offline control, respectively. To overcome these challenges, the central nervous system synergistically integrates multiple sensory modalities and coordinates multiple motor effectors. Among these sensory modalities, tactile sensation plays an important role in manual motor tasks by providing hand-object contact information. The purpose of this study was to investigate the role of tactile feedback in individual finger actions and multi-finger interactions during constant force production tasks. We developed analytical techniques for the linear decomposition of the overall variance in the motor system in both online and offline control. We removed tactile feedback from the fingers and demonstrated that tactile sensors played a critical role in the online control of synergistic interactions between fingers. In contrast, the same sensors did not contribute to offline control. We also demonstrated that when tactile feedback was removed from the fingers, the combined motor output of individual fingers did not change while individual finger behaviors did. This finding supports the idea of hierarchical control where individual fingers at the lower level work together to stabilize the performance of combined motor output at the higher level.

Effects of the high-power pain threshold ultrasound technique in the elderly with latent myofascial trigger points: a double-blind randomized study.

BACKGROUND AND OBJECTIVE: The high-power pain threshold ultrasound (HPPTUS) technique has been introduced as a novel treatment method in patients with myofascial trigger points (MTrPs). The aim of the current study was to compare the therapeutic effects of HPPTUS with those of the conventional ultrasound technique in elderly patients with latent MTrPs on the upper trapezius muscles of at least 1 side. MATERIAL AND METHODS: Forty-one participants received 8 treatment sessions with conventional ultrasound (n=19) or with the HPPTUS technique (n=22) for 4 consecutive weeks. Outcome variables included visual analog scale (VAS) scores, pressure pain threshold (PPT), and range of motion (ROM). The data were analyzed using repeated analysis of variance (ANOVA) measurements. RESULTS: The VAS scores recorded 1, 2, 3, and 4 weeks after HPPTUS were significantly lower than the baseline scores in both groups. The ROM (after 3 and 4 weeks) and PPT (after 4 weeks) values also significantly increased from their baseline values in both groups. On comparing the techniques, there were no significant differences in the VAS (p=0.296), PPT (p=0.768), and ROM (p=0.822) values, although both techniques showed therapeutic effects for 4 weeks (p < 0.001). CONCLUSION: The results indicate that the HPPTUS technique in same manner as treatment of active MTrPs is not superior to the conventional ultrasound technique in the treatment of the elderly patients with the latent MTrPs.

Cutaneous sensory feedback plays a critical role in agonist-antagonist co-activation.

The purpose of this study was to investigate the role of cutaneous feedback in the agonist-antagonist co-activation mechanism during maximum voluntary force (MVF) production by the fingers. Seventeen healthy male subjects (age: 23.8 ± 1.0 years) were asked to press with maximal effort at their fingertips. Finger forces at the fingertips and muscle activities of the flexor digitorum superficialis (FDS, agonist) and extensor digitorum communis (EDC, antagonist) were recorded using force sensors and electromyography, respectively. There were two experimental conditions: with and without administration of a ring block to the fingers (i.e., anesthesia and normal conditions, or AC and NC, respectively). The ring block was used to deprive cutaneous feedback. Consistent with previous studies, finger MVF decreased significantly in AC compared with NC. Moreover, the force production of non-task fingers significantly increased in AC. Muscle activity of the EDC was significantly lower in AC than in NC; no significant changes in the FDS muscle were observed. The findings of this study show that cutaneous feedback not only increases MVF and force accuracy, but facilitates agonist-antagonist co-activation by increasing antagonist muscle activation. The results of this study imply that cutaneous feedback is linked to both primary and adjacent motor neurons.

Tactile feedback plays a critical role in maximum finger force production.

This study investigates the role of cutaneous feedback on maximum voluntary force (MVF), finger force deficit (FD) and finger independence (FI). FD was calculated as the difference between the sum of maximal individual finger forces during single-finger pressing tasks and the maximal force produced by those fingers during an all-finger pressing task. FI was calculated as the average non-task finger forces normalized by the task-finger forces and subtracted from 100 percent. Twenty young healthy right-handed males participated in the study. Cutaneous feedback was removed by administering ring block digital anesthesia on the 2nd, 3rd, 4th and 5th digits of the right hands. Subjects were asked to press force sensors with maximal effort using individual digits as well as all four digits together, with and without cutaneous feedback. Results from the study showed a 25% decrease in MVF for the individual fingers as well as all the four fingers pressing together after the removal of cutaneous feedback. Additionally, more than 100% increase in FD after the removal of cutaneous feedback was observed in the middle and ring fingers. No changes in FI values were observed between the two conditions. Results of this study suggest that the central nervous system utilizes cutaneous feedback and the feedback mechanism plays a critical role in maximal voluntary force production by the hand digits.

Multi-finger pressing synergies change with the level of extra degrees of freedom.

The purpose of this study was to test the principle of motor abundance, which has been hypothesized as the principle by which the central nervous system controls the excessive degrees of freedom of the human movements, in contrast to the traditional negative view of motor redundancy. This study investigated the changes in force stabilizing and moment stabilizing synergies for multi-finger pressing tasks involving different number of fingers. Twelve healthy subjects produced a constant pressing force while watching visual feedback of the total pressing force for the fingers involved in each task. Based on the principle of motor abundance, it was hypothesized that the multi-finger synergies for the total force stabilizing synergy and the total moment stabilizing synergy would be greater as the number of task finger increases. Force stabilizing and moment stabilizing synergies were quantified using the framework of the uncontrolled manifold analysis. It was found that strong force stabilizing synergies existed for all the finger combinations. The index of force stabilizing synergies was greater when the task involved more number of fingers. The index of moment stabilizing synergies was negative for the two-finger combination, representing moment destabilizing synergies. However, the index of moment stabilizing synergies was positive for three-finger and four-finger combinations, representing strong moment stabilizing synergies for these finger combinations. We interpret the findings as an evidence for the principle of abundance for stabilization of both, total force as well as total moment.

Long-term treadmill exercise-induced neuroplasticity and associated memory recovery of streptozotocin-induced diabetic rats: an experimenter blind, randomized controlled study.

We investigated a long-term exercise-induced neuroplasticity and spatial memory recovery in 15 rats in a treadmill as follows: normal control rats (NC), streptozotocin (STZ)-induced diabetic control rats (DC), and STZ-induced diabetic rats exercising in a treadmill (DE). As per the DE group, the running exercise in a treadmill was administered for 30 minutes a day for 6 weeks. Neuronal immediate-early gene (IEG) expression (c-Fos) in the hippocampus and radial arm maze (RAM) tests were measured and revealed that the c-Fos levels in DE were significantly higher than those in NC and DC (p < 0.05). Behavioral data analysis indicated that spatial memory performance scores, obtained from the RAM test, were significantly different among the three groups (p < 0.05). The memory scores of NC and DE were higher than those of DC (p < 0.05). These findings suggest that exercising in the treadmill increased neuronal immediate-early gene expression associated with neuroplasticity, thereby improving spatial memory. This is the first experimental evidence in literature that supports the efficacy of exercise-induced neuroplasticity and spatial motor memory in diabetes care.