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The American Journal of Sports Medicine Oct 2023Adipokines represent a spectrum of bioactive molecules that could modulate fibroblastic and inflammatory processes. The role of adipokines in the pathogenesis of frozen...
BACKGROUND
Adipokines represent a spectrum of bioactive molecules that could modulate fibroblastic and inflammatory processes. The role of adipokines in the pathogenesis of frozen shoulder (FS), a common musculoskeletal disorder characterized by chronic inflammation, remains obscure.
PURPOSE
To evaluate whether adipokines contribute to the pathogenic mechanisms of FS and to evaluate any potential correlation of adipokines with patients' symptoms.
STUDY DESIGN
Controlled laboratory study.
METHODS
Shoulder capsule specimens were obtained from 10 patients with FS and 10 patients with shoulder instability (control group). The specimens were dyed using hematoxylin and eosin and immunohistochemically assessed with antibodies targeting adipokines, collagen I, collagen III, and tumor necrosis factor α. Immunoreactivity was graded from "no" to "strong" in a blinded manner. Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) analysis was conducted. Before the surgery, patient-reported frequency of pain, severity of pain, stiffness, and shoulder range of motion were documented.
RESULTS
In comparison with the control group, patients with FS had significantly greater pain frequency, pain severity, and stiffness and more limited shoulder range of motion ( < .001). Hematoxylin and eosin- and Masson trichrome-stained samples from the FS group displayed hypercellularity and increased collagen fibers. Immunohistochemistry and RT-qPCR analyses indicated that expression of adipokines was significantly increased in FS capsules compared with the control group. The expression of collagen I, collagen III, and tumor necrosis factor α was also increased in FS capsules. No significant correlation was noted between adipokine expression and patient-reported outcomes in the control group, whereas in patients with FS, adiponectin expression was correlated with pain frequency ( = 0.78; = .01) and stiffness ( = 0.73; = .02). Visfatin was also correlated with pain frequency ( = 0.70; = .02).
CONCLUSION/CLINICAL RELEVANCE
This study indicated a potential role for adipokines in the pathogenesis of FS and demonstrated a correlation between adipokine expression and patients' pain and stiffness.
Topics: Humans; Adipokines; Joint Instability; Tumor Necrosis Factor-alpha; Eosine Yellowish-(YS); Hematoxylin; Shoulder Joint; Bursitis; Pain
PubMed: 37615177
DOI: 10.1177/03635465231189797 -
Unfallchirurgie (Heidelberg, Germany) Sep 2023So far there are no clear recommendations for postoperative follow-up treatment of elbow injuries and individual concepts are often chosen. Due to the susceptibility for... (Review)
Review
So far there are no clear recommendations for postoperative follow-up treatment of elbow injuries and individual concepts are often chosen. Due to the susceptibility for posttraumatic or postoperative impaired movement up to stiffness of the elbow joint, early mobilization plays a crucial role. Therefore, mid-term to long-term immobilization should be avoided. In addition to the necessary cryotherapy and compression therapy for swelling and pain control in the initial period, early actively assisted mobilization now has an important role. Additionally, active flexion and extension in an overhead position, so-called overhead motion, was recently established. After a short initial immobilization in a cast, mostly 3-5 days, the cast is changed to a dynamic movement orthosis, which when possible enables a free range of motion. Care is taken that varus and valgus loading is avoided. In general loading is avoided for the first 6 weeks, followed by a stepwise increase of loading up to maximum loading. In most cases return to sport is possible after 3 months. After implantation of an elbow prosthesis a maximum loading of 5 kg for single loading and 1 kg for repetitive loading are recommended.
Topics: Humans; Elbow Injuries; Follow-Up Studies; Arm Injuries; Elbow Joint; Movement
PubMed: 37278730
DOI: 10.1007/s00113-023-01327-8 -
Journal of ISAKOS : Joint Disorders &... Apr 2024Stiffness is a clinical disorder that affects the patient's function of the entire upper limb. Many classifications systems have been developed for elbow stiffness based...
Stiffness is a clinical disorder that affects the patient's function of the entire upper limb. Many classifications systems have been developed for elbow stiffness based on the plane of motion, severity, aetiology, prognosis or anatomical location. A new classification, the Stiffness types and Influencing Factors Classification System, is proposed as a treatment algorithm to guide the surgical treatment and the preferred operative approach (open or arthroscopic).
Topics: Humans; Contracture; Elbow; Elbow Joint; Joint Diseases; Prognosis
PubMed: 37923144
DOI: 10.1016/j.jisako.2023.10.011 -
The Review of Scientific Instruments Feb 2024This paper develops an antagonistic variable-stiffness pneumatic flexible joint in which two groups of artificial muscles are symmetrically distributed on both sides of...
This paper develops an antagonistic variable-stiffness pneumatic flexible joint in which two groups of artificial muscles are symmetrically distributed on both sides of the elastic thin plate. The elastic thin plate restricts the axial movement of the joint. Therefore, the joint can achieve single-dimensional and bidirectional bending by controlling the air pressure value of the pneumatic artificial muscle. Two variable stiffness elastic dampers are also symmetrically installed on both sides of the elastic thin plate, using a positive-pressure driving method to achieve real-time posture maintenance function of the joint based on particle-blockage, wedge structure, and antagonistic effect. The mathematical models for the bending angle and stiffness of flexible joints were established, and relevant experiments were conducted. When the air pressure of the pneumatic artificial muscle is 0.32 MPa, the joint bending angle reaches 62.7°. When the bending angle is 60° and the air pressure of the variable-stiffness elastic damper is 0.5 MPa, the stiffness in the bending direction of the flexible joint with the variable-stiffness elastic damper is 6.9 times that of the flexible joint without the variable-stiffness elastic damper, and the stiffness in the reverse bending direction is 10.3 times that of the flexible joint without the variable-stiffness elastic damper under the same conditions.
Topics: Movement; Muscles; Air Pressure
PubMed: 38416042
DOI: 10.1063/5.0186757 -
Journal of ISAKOS : Joint Disorders &... Feb 2024In elbow stiffness, pre-operative assessments should identify the articular and peri-articular tissues involved and, more specifically, they should determine how...
In elbow stiffness, pre-operative assessments should identify the articular and peri-articular tissues involved and, more specifically, they should determine how preserved the articular surfaces and osteo-articular congruity are. We will focus on the most important conditions and tissue reactions after trauma in order to understand the causes of joint stiffness. A logical surgical planning is based upon a deep knowledge of the anatomical obstacles and of the associated lesions that the trauma provoked with. The peri-articular soft tissue contractures. The osteo-articular incongruity.
Topics: Humans; Elbow; Elbow Joint; Elbow Injuries; Treatment Outcome; Joint Dislocations; Arthritis; Ossification, Heterotopic
PubMed: 37879605
DOI: 10.1016/j.jisako.2023.10.009 -
Sports Biomechanics Nov 2023In some sporting events (e.g., long-distance running), the ability to maintain joint stiffness is considered an essential physical ability. However, the determinants of...
In some sporting events (e.g., long-distance running), the ability to maintain joint stiffness is considered an essential physical ability. However, the determinants of joint stiffness endurance remain unclear. This study aimed to examine the effects of muscular endurance and tendon extensibility on joint stiffness endurance. Thirteen males performed the fatigue task (5 sets of 50 hopping). Ankle joint stiffness during drop jump was measured before and after fatigue task. The maximum number of repetitions at 30% of one repetition maximum for plantar flexion was measured as muscular endurance. Maximal elongation of the Achilles tendon was measured during ramp (with a low strain rate of tendon) and ballistic (with a high strain rate of tendon) contractions as tendon extensibility. Joint stiffness significantly decreased by 7.5% after the fatigue task ( = 0.033). The maximum number of repetitions at 30% of 1RM (79.6 ± 48.7 repetitions) was not significantly correlated with the relative change in joint stiffness ( = 0.283, = 0.348). The maximal elongation of the Achilles tendon measured during ramp and ballistic contractions were not significantly associated with the relative change in joint stiffness ( = 0.326, = 0.277 for ramp contraction; = 0.438, = 0.135 for ballistic contraction). These results suggest that muscular endurance and tendon extensibility were unrelated to joint stiffness endurance.
PubMed: 37921271
DOI: 10.1080/14763141.2023.2275254 -
Sports (Basel, Switzerland) Nov 2023Soccer players with chronic ankle instability (CAI) may stabilize their supporting leg by the proximal joint to compensate for the ankle instability during kicking...
Soccer players with chronic ankle instability (CAI) may stabilize their supporting leg by the proximal joint to compensate for the ankle instability during kicking motion. This study aimed to investigate the characteristics of leg and joint stiffness of the supporting leg during side-foot kicking in soccer players with CAI. Twenty-four male collegiate-level soccer players with and without CAI participated in this study. The kinematic and kinetic data were obtained using a three-dimensional motion analysis system. Leg stiffness and joint (hip, knee, and ankle) stiffness in the sagittal and frontal planes were calculated and analyzed. The results clarified that soccer players with CAI (0.106 ± 0.053 Nm/°) had greater knee stiffness in knee adduction during the kicking cycle compared to those without CAI (0.066 ± 0.030 Nm/°; = 0.046), whereas no characteristic differences were observed in knee stiffness in knee flexion and hip and ankle stiffness ( > 0.05). Knee stiffness is believed to occur to compensate for ankle joint instability in the supporting leg. Therefore, adjusting knee stiffness to accommodate ankle joint instability is crucial for maintaining kicking performance. Based on results of this study, it may be important to consider training and exercises focused on joint coordination to improve knee stiffness in soccer players with CAI.
PubMed: 37999435
DOI: 10.3390/sports11110218 -
Frontiers in Bioengineering and... 2024Musculoskeletal multibody models of the spine can be used to investigate the biomechanical behaviour of the spine. In this context, a correct characterisation of the...
Musculoskeletal multibody models of the spine can be used to investigate the biomechanical behaviour of the spine. In this context, a correct characterisation of the passive mechanical properties of the intervertebral joint is crucial. The intervertebral joint stiffness, in particular, is typically derived from the literature, and the differences between individuals and spine levels are often disregarded. This study tested if an optimisation method of personalising the intervertebral joint stiffnesses was able to capture expected stiffness variation between specimens and between spine levels and if the variation between spine levels could be accurately captured using a generic scaling ratio. Multibody models of six T12 to sacrum spine specimens were created from computed tomography data. For each specimen, two models were created: one with uniform stiffnesses across spine levels, and one accounting for level dependency. Three loading conditions were simulated. The initial stiffness values were optimised to minimize the kinematic error. There was a range of optimised stiffnesses across the specimens and the models with level dependent stiffnesses were less accurate than the models without. Using an optimised stiffness substantially reduced prediction errors. The optimisation captured the expected variation between specimens, and the prediction errors demonstrated the importance of accounting for level dependency. The inaccuracy of the predicted kinematics for the level-dependent models indicated that a generic scaling ratio is not a suitable method to account for the level dependency. The variation in the optimised stiffnesses for the different loading conditions indicates personalised stiffnesses should also be considered load-specific.
PubMed: 38486868
DOI: 10.3389/fbioe.2024.1372088 -
Soft Robotics Oct 2023Continuum robots have the advantages of agility and adaptability. However, existing continuum robots have limitations of low stiffness and complex motion modes, and the...
Continuum robots have the advantages of agility and adaptability. However, existing continuum robots have limitations of low stiffness and complex motion modes, and the existing variable stiffness methods cannot achieve a wide range of stiffness changes and fast switching stiffness simultaneously. A continuum robot structure, switching stiffness method, and motion principle are proposed in this article. The continuum robot is made up of three segments connected in series. Each segment comprises multiple spherical joints connected in series, and the joints can be locked by their respective airbag. A valve controls each airbag, quickly switching the segment between rigidity and flexibility. The motion of the segments is driven by three cables that run through the robot. The segment steers only when it is unlocked. When a segment becomes locked, it acts as a rigid body. As a result, by locking and unlocking each segment in sequence, the cables can alternately drive all the segments. The stiffness variation and movement of the continuum robot were tested. The segment's stiffness varies from 36.89 to 1300.95 N/m and the stiffness switching time is 0.25-0.48 s. The time-sharing control mode of segment stiffness and motion is validated by establishing a specific test platform and a mathematical model. The continuum robot's flexibility is demonstrated by controlling the fast bending of different segments sequentially.
PubMed: 37184583
DOI: 10.1089/soro.2022.0179 -
Asia-Pacific Journal of Sports... Oct 2023Joint stiffness results from the coupling of the nervous system and joint mechanics, and thus stiffness is a comprehensive representation of joint stability. It has been...
OBJECTIVE
Joint stiffness results from the coupling of the nervous system and joint mechanics, and thus stiffness is a comprehensive representation of joint stability. It has been reported that moxibustion can alleviate general weakness and fatigue symptoms and subsequently may influence joint stiffness. This study investigated whether moxibustion could enhance knee joint stiffness in recreational athletes pre- and post-fatigue.
METHODS
Eighteen participants were randomized into intervention (5 males: 20.6 ± 1.5 yr; 4 females: 20.8 ± 1.5 yr) and control groups (5 males: 19.4 ± 0.9 yr; 4 females: 20.5 ± 0.6 yr). The intervention group received indirect moxibustion applied to acupoints ST36 (bilateral) and CV4 for 30 min every other day for 4 consecutive weeks. The control group maintained regular exercise without moxibustion. Peak torque (PT) of right knee extensor, relaxed and contracted muscle stiffness (MS) of vastus lateralis, and knee extensor musculoarticular stiffness (MAS) was assessed with an isokinetic dynamometer (IsoMed 2000), myometer, and free oscillation technique, respectively. Measurements were taken at three time points: pre-intervention, post-intervention/pre-fatigue, and post-fatigue.
RESULTS
MAS (P = 0.006) and PT (P = 0.007) in the intervention group increased more from pre-to post-intervention compared with the control group. Post-fatigue MAS (P = 0.016) and PT (P = 0.031) increased more in the intervention group than in the control group.
CONCLUSION
Moxibustion enhanced PT and knee MAS, suggesting that this intervention could be used in injury prevention and benefit fatigue resistance in young recreational athletes.
PubMed: 37800098
DOI: 10.1016/j.asmart.2023.08.004