Analysis of muscle activations in lower extremities muscles at various angles of ankle flexion using wedges during static squat exercise

[Purpose] This study aimed to investigate changes in activation of the rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius muscles during one-legged squats performed at various angles of ankle flexion. With the use of wedges, the muscles were activated at different angles of ankle flexion angles to establish the appropriate posture necessary for muscle strengthening and rehabilitation. [Subjects and Methods] Healthy adults aged 20–40 years were recruited from Good Morning Hospital in Ulsan City. Of the 22 participants, two dropped out during the tests, leaving a final sample of 20 participants. The wedges were 100 mm wide and 200 mm long and had inclinations of 10°, 30°, and 50°. EMG Analyzer software was used to measure muscle activation. [Results] A significant difference in the activation of the rectus femoris muscle at various angles of ankle flexion was seen. The gastrocnemius muscle exhibited significant differences in activation among the 0°–30°, 0°–50°, and 10°–50° inclinations. [Conclusion] Wedge-assisted muscle activation under different ankle flexion angles can be introduced as an effective exercise option under clinical conditions.

Principles and applications of therapeutic exercises for small animals

Therapeutic exercises are the cornerstone of the rehabilitation programs of companion animals. Therapeutic exercises are used to improve active joint range of motion, to improve weight bearing and limb use, to build strength and muscle mass, and to increase conditioning (eg, endurance, speed). Each case is unique as chronicity, type of injury, patient signalment and temperament, owner compliance, and level of required functional recovery vary widely. Therapeutic exercises are also essential for partial return to work or performance and to learn to perform activities of daily living after injury or surgery.

Don't get caught flat footed - how over-pronation may just be a dysfunctional model

For many years there has been a long-held clinical belief that a flat or over-pronating foot should be supported; yet in every other part of the body it has long been recognised that use of support (if at all) should generally be limited to acute rehabilitation. Why should the foot be any different? To support a biological structure, in the long term, is to weaken it. Panjabi's model of joint stability offers insight into why the idea of arch support, as well-intentioned as it may have been, may be a dysfunctional model. A test (and conditioning exercise) is presented which appears to support the notion that there is no such thing as a flat foot; only a de-conditioned foot.

Strengthening of defected beam-column joints using CFRP

This paper presents an experimental study for the structural performance of reinforced concrete (RC) exterior beam–column joints rehabilitated using carbon-fiber-reinforced polymer (CFRP). The present experimental program consists of testing 10 half-scale specimens divided into three groups covering three possible defects in addition to an adequately detailed control specimen. The considered defects include the absence of the transverse reinforcement within the joint core, insufficient bond length for the beam main reinforcement and inadequate spliced implanted column on the joint. Three different strengthening schemes were used to rehabilitate the defected beam–column joints including externally bonded CFRP strips and sheets in addition to near surface mounted (NSM) CFRP strips. The failure criteria including ultimate capacity, mode of failure, initial stiffness, ductility and the developed ultimate strain in the reinforcing steel and CFRP were considered and compared for each group for the control and the CFRP-strengthened specimens. The test results showed that the proposed CFRP strengthening configurations represented the best choice for strengthening the first two defects from the viewpoint of the studied failure criteria. On the other hand, the results of the third group showed that strengthening the joint using NSM strip technique enabled the specimen to outperform the structural performance of the control specimen while strengthening the joints using externally bonded CFRP strips and sheets failed to restore the strengthened joints capacity.

The matrix polysaccharide (1;3,1;4)-β-D-glucan is involved in silicon-dependent strengthening of rice cell wall

Poales [represented by rice (Oryza sativa L.)] in angiosperms and Equisetum (horsetails) in Pteridophytes are two major groups of heavy silicon (Si) accumulators. In rice, Si is polymerized preferentially in the epidermal cell wall, forming Si-cuticle double layers and Si-cellulose double layers beneath the cuticle. This Si layer is thought to exert various beneficial effects on the growth and development of land plants. Although the recent discovery of the influx and efflux transporters of silicic acid has shed some light on the molecular mechanisms of Si uptake and transport in rice, the mechanism underlying the final incorporation of polymerized Si into the cell wall remains elusive. Despite their phylogenetic distance, the cell walls of the two Si accumulators, Poales and Equisetum, share another common component, i.e. (1;3,1;4)-β-D-glucan, also known as mixed-linkage glucan (MLG), a matrix polysaccharide not found in other plants. Based on this coincidence, a possible correlation between the functions of Si and MLG in the cell wall has been suggested, but no experimental evidence has been obtained in support of this functional correlation. Here, we present an analysis of the correlative action of Si and MLG on the mechanical properties of leaf blades using a transgenic rice line in which the MLG level was reduced by overexpressing EGL1, which encodes (1;3,1;4)-β-D-glucanase. The reduction in MLG did not affect total Si accumulation, but it significantly altered the Si distribution profile and reduced the Si-dependent mechanical properties of the leaf blades, strongly suggesting a functional correlation between Si and MLG.

Effects of hand and knee positions on muscular activity during trunk extension exercise with the Roman chair

This experimental study was performed to investigate the effects of hand and knee positions on muscular activity during back extension exercises with the Roman chair. Eighteen asymptomatic male amateur athletes performed four prone back extension exercises with two hand positions (crossed-arms and behind-the-head), and two knee positions (extended knee and 90° flexed knee). Surface electromyography (sEMG) was performed to collect data from the lower trapezius (LT), latissimus dorsi (LD), erector spinae in the T12 paraspinal region (ES-T12), erector spinae at the L3 level (ES-L3), gluteus maximus (GM), and biceps femoris (BF). Two-way repeated analysis of variance with two within-subject factors (two hand positions and two knee positions) was used to determine the significance of differences between the exercise conditions, and which hand and knee positions resulted in greater activation with exercise variation. The root mean square sEMG values were normalized using the maximum voluntary isometric contraction (MVIC) and represented as the % of the maximum EMG (%mEMG). There was no significant interaction between knee and hand positions in the %mEMG data. The results showed that the hand position affected the normalized activation of LT; the behind-the-head position resulted in significantly greater muscle activation than the crossed-arms hand position (P<0.05). The activations of the LD, ES-T10, ES-L4, and GM were greater in the 90° flexed-knee position compared to the extended-knee position (P<0.05). Although back extension exercise using the Roman chair has been shown to effectively activate the extensor musculature, our results indicated that changing the knee and hand positions could activate specific muscles differently. To achieve greater activation of trunk extensor muscle during extension exercise with the Roman chair, the flexed-knee position is a useful means of increasing resistance.

Principles of postoperative anterior cruciate ligament rehabilitation

It is known that anterior cruciate ligament (ACL) reconstruction needs to be combined with detailed postoperative rehabilitation in order for patients to return to their pre-injury activity levels, and that the rehabilitation process is as important as the reconstruction surgery. Literature studies focus on how early in the postoperative ACL rehabilitation period rehabilitation modalities can be initiated. Despite the sheer number of studies on this topic, postoperative ACL rehabilitation protocols have not been standardized yet. Could common, “ossified” knowledge or modalities really prove themselves in the literature? Could questions such as “is postoperative brace use really necessary?”, “what are the benefits of early restoration of the range of motion (ROM)?”, “to what extent is neuromuscular electrical stimulation (NMES) effective in the protection from muscular atrophy?”, “how early can proprioception training and open chain exercises begin?”, “should strengthening training start in the immediate postoperative period?” be answered for sure? My aim is to review postoperative brace use, early ROM restoration, NMES, proprioception, open/closed chain exercises and early strengthening, which are common modalities in the very comprehensive theme of postoperative ACL rehabilitation, on the basis of several studies (Level of Evidence 1 and 2) and to present the commonly accepted ways they are presently used. Moreover, I have presented the objectives of postoperative ACL rehabilitation in tables and recent miscellaneous studies in the last chapter of the paper.

Exercise in osteoarthritis: moving from prescription to adherence

Exercise is recommended for the management of osteoarthritis (OA) in all clinical guidelines irrespective of disease severity, pain levels, and functional status. For knee OA, evidence supports the benefits of various types of exercise for improving pain and function in the short term. However, there is much less research investigating the effects of exercise in patients with OA at other joints such as the hip and hand. It is important to note that while the magnitude of exercise benefits may be considered small to moderate, these effects are comparable to reported estimates for simple analgesics and oral nonsteroidal anti-inflammatory drugs for OA pain but exercise has much fewer side effects. Exercise prescription should be individualized based on assessment findings and be patient centered involving shared decision making between the patient and clinician. Given that patient adherence to exercise declines over time, appropriate attention should be pain as reduced adherence attenuates the benefits of exercise. Given this, barriers and facilitators to exercise should be identified and strategies to maximize long-term adherence to exercise implemented.

Atomistic deformation mechanisms in twinned copper nanospheres

In the present study, we perform molecular dynamic simulations to investigate the compression response and atomistic deformation mechanisms of twinned nanospheres. The relationship between load and compression depth is calculated for various twin spacing and loading directions. Then, the overall elastic properties and the underlying plastic deformation mechanisms are illuminated. Twin boundaries (TBs) act as obstacles to dislocation motion and lead to strengthening. As the loading direction varies, the plastic deformation transfers from dislocations intersecting with TBs, slipping parallel to TBs, and then to being restrained by TBs. The strengthening of TBs depends strongly on the twin spacing.

Comparative study of hamstring and quadriceps strengthening treatments in the management of knee osteoarthritis

[Purpose] Osteoarthritis (OA) of the knee is the most common form of joint disease. It is one of the major causes of impaired function that reduces quality of life (QOL) worldwide. The purpose of this study was to compare exercise treatments for hamstring and quadriceps strength in the management of knee osteoarthritis. [Subjects and Methods] Forty patients with OA knee, aged 50–65 years were divided into 2 groups. The first group (57.65±4.78 years) received hot packs and performed strengthening exercises for the quadriceps and hamstring, and stretching exercises for the hamstring. The second group (58.15±5.11 years) received hot packs and performed strengthening exercises for only the quadriceps, and stretching exercise for the hamstring. Outcome measures were the WOMAC (Western Ontario and McMaster Universities OA index questionnaire), Visual Analogue Scale (VAS) assessment of pain, the Fifty-Foot Walk Test (FWS), and Handheld dynamometry. [Results] There was a significant difference between the groups. The first group showed a more significant result than the second group. [Conclusion] Strengthening of the hamstrings in addition to strengthening of the quadriceps was shown to be beneficial for improving subjective knee pain, range of motion and decreasing the limitation of functional performance of patients with knee osteoarthritis.

Meta-analysis of the effect of strengthening interventions in individuals with cerebral palsy

This study aimed to investigate the evidence that strengthening interventions can improve muscle strength and activity in individuals with cerebral palsy. The search focused on studies that employed strength training for children with cerebral palsy for which six electronic databases were used to extract literature published from 2001 to 2012. The key terms used in these searches were combined strength training, strengthening, weight training, weight lifting, resistance, and cerebral palsy. The quality of each study was assessed using the PEDro (Physiotherapy Evidence Database) scale. Thirteen randomized controlled trial studies were selected and divided into categories according to program type, mode, and outcome measures. The overall effect sizes of each study and types of strengthening were large. Strengthening exercise improved muscle strength to a greater degree, when practiced 3 times per week in 40-50 min sessions than in other categories of session length, and greater improvement was observed in younger children than in older. The effect size of the activities and variables related to gait, except for gait endurance, were medium to large. The effect size of individual muscles was large, but the effect sizes for ankle plantar flexor, hip abductor/adductor, and extensor were insignificant. Strengthening interventions are useful for increasing muscle strength in individuals with cerebral palsy, specifically in youth and children, and optimal exercise consisted of 40- to 50-min sessions performed 3 times per week. Although strengthening interventions may improve activities, including gait, more studies that are rigorous are needed to determine the contributions to gross motor function.