Neuromuscular spindles relative to joint movement complexities

In various forms of movement of finger rehabilitation training, Continuous Passive Motion (CPM) of single degree of freedom (1 DOF) has outstanding application value. Taking classic flexion and extension movement for instance, this study collected the joint angle data of finger flexion and extension motion by experiments and confirmed that the joint motion of finger are not independent of each other but there is certain rule. This paper studies the finger joint movement rule from qualitative and quantitative aspects, and the conclusion can guide the design of the mechanism and control method of finger rehabilitation training robot.

Download Full-text

Myofascial Release of the Hamstrings Improves Physical Performance—A Study of Young Adults

Healthcare ◽

10.3390/healthcare9060674 ◽

2021 ◽

Vol 9 (6) ◽

pp. 674

Author(s):

Keisuke Itotani ◽

Kanta Kawahata ◽

Wakana Takashima ◽

Wakana Mita ◽

Hitomi Minematsu ◽

...

Keyword(s):

Young Adults ◽

Physical Performance ◽

Walking Speed ◽

Quadriceps Muscle ◽

Lower Limbs ◽

Joint Movement ◽

Myofascial Release ◽

Functional Reach Test ◽

Hamstring Flexibility ◽

Walking Speeds

Physical performance is mainly assessed in terms of gait speed, chair rise capacity, and balance skills, and assessments are often carried out on the lower limbs. Such physical performance is largely influenced by the strength of the quadriceps and hamstrings muscles. Flexibility of the hamstrings is important because quadriceps muscle activity influences the hip flexion angle. Therefore, hamstring flexibility is essential to improve physical performance. In this study, Myofascial Release (MFR) was applied to the hamstrings to evaluate its effects. MFR on the hamstrings was performed on 17 young adults. Physical function and physical performance were measured before, immediately after, and 5 days after the MFR intervention: finger floor distance (FFD), range of motion (ROM) of the straight leg raising test (SLR), standing long jump (SLJ), squat jump (SJ), functional reach test (FRT), comfortable walking speeds (C-walking speed), and maximum walking speeds (M-walking speed). The results of the analysis show a significant increase in FFD (−2.6 ± 8.9 vs. 0.4 ± 9.4 vs. 2.4 ± 8.9, p < 0.01), SLJ (185.6 ± 44.5 vs. 185.0 ± 41.8 vs. 196.6 ± 40.1, p < 0.01), and M-walking speed (2.9 ± 0.6 vs. 3.0 ± 0.6 vs. 3.3 ± 0.6, p < 0.01). This study has shown that MFR for hamstrings not only improves flexibility but also increases M-walking speed and physical performance of the SLJ. As MFR is safe and does not involve joint movement, it may be useful for maintaining and improving performance and flexibility during inactivity and for stretching before exercise.

Download Full-text

Modeling the resistance mechanism of passive knee joint flexion and extension for use in rehabilitation equipment

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1177/0954411921990133 ◽

2021 ◽

pp. 095441192199013

Author(s):

Mansoor Amiri ◽

Farhad Tabatabai Ghomsheh ◽

Farshad Ghazalian

Keyword(s):

Knee Joint ◽

Sagittal Plane ◽

Resistance Mechanism ◽

Time Dependent ◽

Coefficient Of Determination ◽

Joint Movement ◽

Elastic Coefficient ◽

Knee Movement ◽

Joint Flexion ◽

Flexion And Extension

The purpose of this study was to model the resistance mechanism of Passive Knee Joint Flexion and Extension to create a similar torque mechanism in rehabilitation equipment. In order to better model the behavior of passive knee tissues, it is necessary to exactly calculate the two coefficients of elasticity of time-independent and time-dependent parts. Ten healthy male volunteers (mean height 176.4+/−4.59 cm) participated in this study. Passive knee joint flexion and extension occurred at velocities of 15, 45, and 120 (degree/s), and in five consecutive cycles and within the range of 0 to 100° of knee movement on the sagittal plane on Cybex isokinetic dynamometer. To ensure that the muscles were relaxed, the electrical activity of knee muscles was recorded. The elastic coefficient, (KS) increased with elevating the passive velocity in flexion and extension. The elastic coefficient, (KP) was observed to grow with the passive velocity increase. While, the viscous coefficient (C) diminished with passive velocity rise in extension and flexion. The heightened passive velocity of the motion resulted in increased hysteresis (at a rate of 42%). The desired of passive velocity is lower so that there is less energy lost and the viscoelastic resistance of the tissue in the movement decreases. The Coefficient of Determination, R2 between the model-responses and experimental curves in the extension was 0.96 < R2 < 0.99 and in flexion was 0.95 < R2 < 0.99. This modeling is capable of predicting the true performance of the components of passive knee movement and we can create a resistance mechanism in the rehabilitation equipment to perform knee joint movement. Quantitative measurements of two elastic coefficients of Time-independent and Time-dependent parts passive knee joint coefficients should be used for better accurate simulation the behavior of passive tissues in the knee which is not seen in other studies.

Download Full-text

Treadmill Exercise after Controlled Abnormal Joint Movement Inhibits Cartilage Degeneration and Synovitis

Life ◽

10.3390/life11040303 ◽

2021 ◽

Vol 11 (4) ◽

pp. 303

Author(s):

Yuichiro Oka ◽

Kenij Murata ◽

Kaichi Ozone ◽

Takuma Kano ◽

Yuki Minegishi ◽

...

Keyword(s):

Treadmill Exercise ◽

Cruciate Ligament ◽

Cartilage Degeneration ◽

Research Society ◽

Therapeutic Effects ◽

Joint Movement ◽

Knee Oa ◽

Anterior Cruciate ◽

Safranin O ◽

Walking Group

Cartilage degeneration is the main pathological component of knee osteoarthritis (OA), but no effective treatment for its control exists. Although exercise can inhibit OA, the abnormal joint movement with knee OA must be managed to perform exercise. Our aims were to determine how controlling abnormal joint movement and treadmill exercise can suppress cartilage degeneration, to analyze the tissues surrounding articular cartilage, and to clarify the effect of treatment. Twelve-week-old ICR mice (n = 24) underwent anterior cruciate ligament transection (ACL-T) surgery on their right knees and were divided into three groups as follows: ACL-T, animals in the walking group subjected to ACL-T; controlled abnormal joint movement (CAJM), and CAJM with exercise (CAJM + Ex) (n = 8/group). Walking-group animals were subjected to treadmill exercise 6 weeks after surgery, including walking for 18 m/min, 30 min/day, 3 days/week for 8 weeks. Safranin-O staining, hematoxylin-eosin staining, and immunohistochemical staining were performed. The OARSI (Osteoarthritis research Society international) score was lower in the CAJM group than in the ACL-T group and was even lower in the CAJM + Ex group. The CAJM group had a lower meniscal injury score than the ACL-T group, and the CAJM + Ex group demonstrated a less severe synovitis than the ACL-T and CAJM groups. The observed difference in the perichondrium tissue damage score depending on the intervention method suggests different therapeutic effects, that normalizing joint motion can solve local problems in the knee joint, and that the anti-inflammatory effect of treadmill exercise can suppress cartilage degeneration.

Download Full-text

Moving apart together: co-movement of a symbiont community and their ant host, and its importance for community assembly

Movement Ecology ◽

10.1186/s40462-021-00259-5 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

T. Parmentier ◽

R. Claus ◽

F. De Laender ◽

D. Bonte

Keyword(s):

Community Assembly ◽

Species Interactions ◽

Spatial Dynamics ◽

Joint Movement ◽

Red Wood Ants ◽

Ant Nests ◽

Mobile Species ◽

Directional Movement ◽

Wood Ants ◽

Red Wood Ant

Abstract Background Species interactions may affect spatial dynamics when the movement of one species is determined by the presence of another one. The most direct species-dependence of dispersal is vectored, usually cross-kingdom, movement of immobile parasites, diseases or seeds by mobile animals. Joint movements of species should, however, not be vectored by definition, as even mobile species are predicted to move together when they are tightly connected in symbiont communities. Methods We studied concerted movements in a diverse and heterogeneous community of arthropods (myrmecophiles) associated with red wood ants. We questioned whether joint-movement strategies eventually determine and speed-up community succession. Results We recorded an astonishingly high number of obligate myrmecophiles outside red wood ant nests. They preferentially co-moved with the host ants as the highest densities were found in locations with the highest density of foraging red wood ants, such as along the network of ant trails. These observations suggest that myrmecophiles resort to the host to move away from the nest, and this to a much higher extent than hitherto anticipated. Interestingly, functional groups of symbionts displayed different dispersal kernels, with predatory myrmecophiles moving more frequently and further from the nest than detritivorous myrmecophiles. We discovered that myrmecophile diversity was lower in newly founded nests than in mature red wood ant nests. Most myrmecophiles, however, were able to colonize new nests fast suggesting that the heterogeneity in mobility does not affect community assembly. Conclusions We show that co-movement is not restricted to tight parasitic, or cross-kingdom interactions. Movement in social insect symbiont communities may be heterogeneous and functional group-dependent, but clearly affected by host movement. Ultimately, this co-movement leads to directional movement and allows a fast colonisation of new patches, but not in a predictable way. This study highlights the importance of spatial dynamics of local and regional networks in symbiont metacommunities, of which those of symbionts of social insects are prime examples.

Download Full-text

Evidence for a vertebrate catapult: elastic energy storage in the plantaris tendon during frog jumping

Biology Letters ◽

10.1098/rsbl.2011.0982 ◽

2011 ◽

Vol 8 (3) ◽

pp. 386-389 ◽

Cited By ~ 85

Author(s):

Henry C. Astley ◽

Thomas J. Roberts

Keyword(s):

Energy Storage ◽

Elastic Energy ◽

High Speed ◽

Angular Acceleration ◽

Whole Body ◽

Joint Motion ◽

Joint Movement ◽

Fascicle Length ◽

Muscle Fascicle ◽

Muscle Shortening

Anuran jumping is one of the most powerful accelerations in vertebrate locomotion. Several species are hypothesized to use a catapult-like mechanism to store and rapidly release elastic energy, producing power outputs far beyond the capability of muscle. Most evidence for this mechanism comes from measurements of whole-body power output; the decoupling of joint motion and muscle shortening expected in a catapult-like mechanism has not been demonstrated. We used high-speed marker-based biplanar X-ray cinefluoroscopy to quantify plantaris muscle fascicle strain and ankle joint motion in frogs in order to test for two hallmarks of a catapult mechanism: (i) shortening of fascicles prior to joint movement (during tendon stretch), and (ii) rapid joint movement during the jump without rapid muscle-shortening (during tendon recoil). During all jumps, muscle fascicles shortened by an average of 7.8 per cent (54% of total strain) prior to joint movement, stretching the tendon. The subsequent period of initial joint movement and high joint angular acceleration occurred with minimal muscle fascicle length change, consistent with the recoil of the elastic tendon. These data support the plantaris longus tendon as a site of elastic energy storage during frog jumping, and demonstrate that catapult mechanisms may be employed even in sub-maximal jumps.

Download Full-text