-
Journal of Neuroengineering and... Aug 2021User preference has the potential to facilitate the design, control, and prescription of prostheses, but we do not yet understand which physiological factors drive...
BACKGROUND
User preference has the potential to facilitate the design, control, and prescription of prostheses, but we do not yet understand which physiological factors drive preference, or if preference is associated with clinical benefits.
METHODS
Subjects with unilateral below-knee amputation walked on a custom variable-stiffness prosthetic ankle and manipulated a dial to determine their preferred prosthetic ankle stiffness at three walking speeds. We evaluated anthropomorphic, metabolic, biomechanical, and performance-based descriptors at stiffness levels surrounding each subject's preferred stiffness.
RESULTS
Subjects preferred lower stiffness values at their self-selected treadmill walking speed, and elected to walk faster overground with ankle stiffness at or above their preferred stiffness. Preferred stiffness maximized the kinematic symmetry between prosthetic and unaffected joints, but was not significantly correlated with body mass or metabolic rate.
CONCLUSION
These results imply that some physiological factors are weighted more heavily when determining preferred stiffness, and that preference may be associated with clinically relevant improvements in gait.
Topics: Ankle; Ankle Joint; Artificial Limbs; Biomechanical Phenomena; Gait; Humans; Patient Preference; Prosthesis Design; Walking
PubMed: 34433472
DOI: 10.1186/s12984-021-00916-1 -
Arthritis Research & Therapy Sep 2023Osteoarthritis (OA) is a degenerative joint disease associated with aging, which often leads to joint stiffness and disability. Exercise is one of the most important...
BACKGROUND
Osteoarthritis (OA) is a degenerative joint disease associated with aging, which often leads to joint stiffness and disability. Exercise is one of the most important non-pharmacological treatments and is prescribed as an indispensable treatment for OA. However, whether physical exercise is beneficial for preventing the progression of OA symptoms with age is poorly understood. We investigated the effects of exercise on spontaneously developed knee OA using male senescence-accelerated mouse prone 8 (SAMP8).
METHODS
To examine age-related changes in the knee joints of SAMP8, knee articular cartilage changes, synovitis, knee joint flexion and extension angles, swelling, walking ability, and quadriceps muscle atrophy were analyzed at 3, 5, 7, and 9 months. SAMP8 were required to run at a speed of 10 m/min for 15 min/day from 7 to 9 months of age. The knee joint pathologies and symptoms of exercising and non-exercising mice were compared by histological, immunohistochemical, and morphometrical analyses.
RESULTS
The mice presented with various histological changes, including cartilage destruction, osteocyte formation, synovitis, declined joint angles, and swelling. Notably, medial and posterior cartilage destruction was more severe than that of the lateral and anterior cartilage. Knee joint angles were significantly correlated with the histological scores (modified Mankin and OARSI, osteophyte formation and synovial lining cell layer). Exercise did not attenuate cartilage degeneration in the medial and posterior tibial plateau, although the articular cartilage of the anterior and lateral tibial plateau and its histological scores was remained and significantly improved, respectively, by exercise. Exercise suppressed the age-related decline of collagen type II-positive areas in the remaining articular cartilage and improved the OA symptoms. Exercise reduced the expression of monocyte chemoattractant protein (MCP)-1 and tumor necrosis factor (TNF)-α positive macrophages in the synovium.
CONCLUSION
This study revealed that SAMP8 developed spontaneous knee OA with age, which resembled the disease symptoms in humans. Low-intensity exercise temporarily alleviated degeneration of the remaining cartilage, synovitis, and age-related decreases in knee flexion angle, stride length, and muscle atrophy in SAMP8. However, exercise during OA progression with age may cause mechanical stress that could be both beneficial and detrimental to joint health.
Topics: Humans; Mice; Male; Animals; Infant; Osteoarthritis, Knee; Knee Joint; Walking; Cartilage, Articular; Synovitis
PubMed: 37710278
DOI: 10.1186/s13075-023-03162-z -
Bulletin of the NYU Hospital For Joint... 2007Etiologies of elbow contractures can be classified into intrinsic versus extrinsic causes. Posttraumatic elbow stiffness is the most common intrinsic cause and HO... (Review)
Review
Etiologies of elbow contractures can be classified into intrinsic versus extrinsic causes. Posttraumatic elbow stiffness is the most common intrinsic cause and HO formation is the most common extrinsic cause of elbow contractures. Patients who sustain significant elbow trauma and have one or more risk factors for HO formation should be given prophylaxis against HO formation in the form of either indomethacin or radiation therapy. Early excision of HO has been shown to be safe and effective. Nonoperative measures are most effective if used within 6 months of contracture onset. These measures include physical therapy and an aggressive splinting program. If nonoperative measures are unsuccessful and the patient has functionally limiting elbow ROM, then surgical intervention should be considered. Careful preoperative assessment of the ulnar nerve is mandatory, as it may need to be transposed. Satisfactory results have been reported with arthroscopic elbow contracture releases. However, this procedure is technically challenging, with the potential for serious neurovascular complications. Satisfactory results have been published for open procedures as well. The direction of the greatest limitation of motion, the presence of ulnar nerve dysfunction, and the location of osteophytes all help to dictate which surgical approach should be selected.
Topics: Arthroscopy; Collateral Ligaments; Contracture; Elbow Joint; Humans; Ossification, Heterotopic; Range of Motion, Articular; Risk Factors
PubMed: 17539758
DOI: No ID Found -
PloS One 2019Research examining the reliability of stiffness measures during hopping has shown strong consistency in leg-spring stiffness (kleg), but high variability in joint...
Research examining the reliability of stiffness measures during hopping has shown strong consistency in leg-spring stiffness (kleg), but high variability in joint stiffness (kjoint) measures. Sled-based systems (SBS) reduce movement degrees-of-freedom and are used to examine stretch-shortening cycle (SSC) function under controlled conditions. The aim of this study was to examine the reliability of kleg and kjoint during single-leg hopping within an SBSKinematic and kinetic data were collected on four occasions (Day_1, Day_2, Day_3 and Day_3Offset). Participants completed two trials of single-leg hopping at different frequencies (1.5, 2.2 and 3.0 Hz) while attached to an inclined-SBS. Stiffness was determined using models of leg-spring (kleg) and torsional (kjoint) stiffness. Statistical analysis identified absolute and relative measures of reliability. Results showed moderate reliability for kleg at 1.5 Hz between inter-day testing bouts, and weak consistency at 2.2 and 3.0 Hz. Examination of intra-day comparisons showed weak agreement for repeated measures of kleg at 1.5 and 2.2 Hz, but moderate agreement at 3.0 Hz. Limits in kleg reliability were accompanied by weak-to-moderate agreement in kjoint measures across inter- and intra-day testing bouts. Results showed limits in the reliability of stiffness measures relative to previous reports on overground hopping. Lack of consistency in kleg and kjoint may be due to the novelty of hopping within the current inclined-SBS. Constraints imposed on the hopping task resulting from SBS design (e.g. additional chair mass, restricting upper body movement) may have also influenced limits in kleg and kjoint reliability. Researchers should consider these findings when employing inclined-SBS of a similar design to examine SSC function.
Topics: Adolescent; Exercise; Exercise Test; Female; Healthy Volunteers; Humans; Joints; Leg; Male; Reproducibility of Results; Young Adult
PubMed: 31805080
DOI: 10.1371/journal.pone.0225664 -
Acta Biochimica Et Biophysica Sinica Jan 2022The pericellular matrix stiffness is strongly associated with its biochemical and structural changes during the aging and osteoarthritis progress of articular cartilage....
The pericellular matrix stiffness is strongly associated with its biochemical and structural changes during the aging and osteoarthritis progress of articular cartilage. However, how substrate stiffness modulates the chondrocyte regulatory volume decrease (RVD) and calcium signaling in chondrocytes remains unknown. This study aims to investigate the effects of substrate stiffness on the chondrocyte RVD and calcium signaling by recapitulating the physiologically relevant substrate stiffness. Our results showed that substrate stiffness induces completely different dynamical deformations between the cell swelling and recovering progresses. Chondrocytes swell faster on the soft substrate but recovers slower than the stiff substrate during the RVD response induced by the hypo-osmotic challenge. We found that stiff substrate enhances the cytosolic Ca oscillation of chondrocytes in the iso-osmotic medium. Furthermore, chondrocytes exhibit a distinctive cytosolic Ca oscillation during the RVD response. Soft substrate significantly improves the Ca oscillation in the cell swelling process whereas stiff substrate enhances the cytosolic Ca oscillation in the cell recovering process. Our work also suggests that the TRPV4 channel is involved in the chondrocyte sensing substrate stiffness by mediating Ca signaling in a stiffness-dependent manner. This helps to understand a previously unidentified relationship between substrate stiffness and RVD response under the hypo-osmotic challenge. A better understanding of substrate stiffness regulating chondrocyte volume and calcium signaling will aid the development of novel cell-instructive biomaterial to restore cellular functions.
Topics: Calcium; Calcium Signaling; Cartilage, Articular; Chondrocytes; Humans; Osmosis; Osteoarthritis
PubMed: 35130619
DOI: 10.3724/abbs.2021008 -
Deutsches Arzteblatt International Apr 2018Primary finger and thumb joint arthritis is common, with a markedly rising prevalence from age 50 onward. As the population as a whole ages, the need for effective,... (Review)
Review
BACKGROUND
Primary finger and thumb joint arthritis is common, with a markedly rising prevalence from age 50 onward. As the population as a whole ages, the need for effective, stage-appropriate treatment of this condition is increasing.
METHODS
This review is based on pertinent publications retrieved by a selective search in the PubMed and Cochrane Library databases.
RESULTS
Pain on movement and morning stiffness are commonly reported symptoms. Thorough physical examination and plain x-rays are mandatory. In the early stages of primary finger and thumb joint arthritis, a conservative, multimodal treatment approach involving the use of splints, physiotherapy, and non-steroidal anti-inflammatory drugs can be helpful. The intraarticular injection of hyaluronic acid or cortisone seems to relieve pain in the short term, but its long-term efficacy in primary finger and thumb joint arthritis is questionable. Arthrodesis (joint fusion) is a reliable surgical treatment option for arthritis of the metacarpophalangeal and interphalangeal joints of the thumb. For mobility-preserving surgery of the metacarpophalangeal joints of the second through fifth fingers, silicone implant arthroplasty remains the gold standard. Symptomatic, advanced arthritis of the distal interphalangeal joint is most effectively treated with arthrodesis.
CONCLUSION
The efficacy of conservative treatment has been documented in high-quality clinical trials, while that of surgical treatment has not. The various surgical methods have yielded benefits in routine clinical use, but these remain to be assessed in randomized and controlled trials.
Topics: Arthritis; Cysts; Finger Joint; Humans; Injections, Intra-Articular; Radiography; Treatment Outcome
PubMed: 29739493
DOI: 10.3238/arztebl.2018.0269 -
Cartilage Dec 2021Employ an automated indentation technique, using a commercially available machine, to assess the effect of fibroblast growth factor 2 (FGF2) expression on structural...
Automated Indentation Demonstrates Structural Stiffness of Femoral Articular Cartilage and Temporomandibular Joint Mandibular Condylar Cartilage Is Altered in FgF2KO Mice.
OBJECTIVE
Employ an automated indentation technique, using a commercially available machine, to assess the effect of fibroblast growth factor 2 (FGF2) expression on structural stiffness over the surface of both murine femoral articular cartilage (AC) and temporomandibular joint (TMJ) mandibular condylar cartilage (MCC).
DESIGN
Experiments were performed using 3-month-old female homozygote Fgf2KO mice with wild type (WT) littermates. After euthanization, isolated mandibles and hindlimbs were either processed for histology or subjected to automated indentation on a Biomomentum Mach-1 v500csst with a 3-axis motion controller in a phosphate buffered saline bath using a 0.3 mm spherical tip indenter. The effect of indentation depth on normal force was characterized, then structural stiffness was calculated and mapped at multiple positions on the AC and MCC.
RESULTS
Automated indentation of the AC and TMJ MCC was successfully completed and was able to demonstrate both regional variation in structural stiffness and differences between WT and Fgf2KO mice. Structural stiffness values for Fgf2KO AC were significantly smaller than WT at both the medial/anterior ( < 0.05) and medial/posterior ( < 0.05) positions. Global Fgf2KO also lead to a decrease in MCC thickness of the TMJ compared with WT ( < 0.05) and increased structural stiffness values for Fgf2KO at both the posterior and anterior location ( < 0.05).
CONCLUSIONS
Automated indentation spatially resolved differences in structural stiffness between WT and Fgf2KO tissue, demonstrating FGF2 expression affects femoral AC and TMJ MCC. This quantitative method will provide a valuable approach for functional characterization of cartilage tissues in murine models relevant to knee joint and TMJ health and disease.
Topics: Animals; Cartilage, Articular; Female; Femur; Knee Joint; Mandibular Condyle; Mice; Temporomandibular Joint
PubMed: 33012179
DOI: 10.1177/1947603520962565 -
Journal of Medicine and Life Aug 2023Inflammation and hypertrophy of the ankle joint's synovial lining can occur due to various causes. Chronic pain and degenerative changes may be due to synovitis causing...
Inflammation and hypertrophy of the ankle joint's synovial lining can occur due to various causes. Chronic pain and degenerative changes may be due to synovitis causing clinical manifestations through traction on the joint capsule. The failure of conservative treatment for at least six months indicates arthroscopic debridement, which can provide significant pain relief without the morbidity of extensive surgical exposures. This study was therefore conducted to establish the functional results of arthroscopic debridement of the ankle joint in synovitis. Fifteen patients with chronic ankle pain who had not responded to conservative treatment for approximately six months were included in the study. Arthroscopic debridement was performed using a shaver blade, followed by a postoperative ankle physiotherapy regimen. Patients were assessed preoperatively and postoperatively using the AOFAS, FADI, and VAS scores, with a mean follow-up period of 26 months. There was a significant improvement in the final clinical outcomes of the patients. The post-operative VAS score improved to 2.20±0.56 (2-4) (p-value=0.001), the AOFAS score was 86±8.25 (65-98) (p-value-0.001), and the FADI Score was 86.93±7.35(70-96) (p-value=0.001). Thirteen patients (86.67%) achieved outstanding or good results, while two had fair results, according to Meislin's criterion. One patient reported a superficial wound infection, which subsided with antibiotic therapy. The study findings indicate that arthroscopic ankle debridement is an efficient method to treat persistent ankle discomfort induced by synovitis, and it has a low postsurgical complications rate, quicker recovery, and less joint stiffness.
Topics: Humans; Ankle; Ankle Joint; Debridement; Synovitis; Pain; Retrospective Studies; Treatment Outcome
PubMed: 38024814
DOI: 10.25122/jml-2023-0117 -
IEEE Transactions on Bio-medical... Feb 2013The ankle contributes the majority of mechanical power during walking and is a frequently studied joint in biomechanics. Specifically, researchers have extensively...
The ankle contributes the majority of mechanical power during walking and is a frequently studied joint in biomechanics. Specifically, researchers have extensively investigated the torque-angle relationship for the ankle during dynamic tasks, such as walking and running. The slope of this relationship has been termed the "quasi-stiffness." However, over time, researchers have begun to interchange the concepts of quasi-stiffness and stiffness. This is an especially important distinction as researchers currently begin to investigate the appropriate control systems for recently developed powered prosthetic legs. The quasi-stiffness and stiffness are distinct concepts in the context of powered joints, and are equivalent in the context of passive joints. The purpose of this paper is to demonstrate the difference between the stiffness and quasi-stiffness using a simple impedance-controlled inverted pendulum model and a more sophisticated biped walking model, each with the ability to modify the trajectory of an impedance controller's equilibrium angle position. In both cases, stiffness values are specified by the controller and the quasi-stiffness are shown during a single step. Both models have widely varying quasi-stiffness but each have a single stiffness value. Therefore, from this simple modeling approach, the differences and similarities between these two concepts are elucidated.
Topics: Adult; Ankle Joint; Biomechanical Phenomena; Elasticity; Humans; Male; Models, Biological; Torque; Viscosity; Walking
PubMed: 23212310
DOI: 10.1109/TBME.2012.2230261 -
Gerontology 2015Foot pain is highly prevalent in older people and has a significant detrimental impact on mobility and quality of life. In recent years, there has been increased... (Review)
Review
Foot pain is highly prevalent in older people and has a significant detrimental impact on mobility and quality of life. In recent years, there has been increased interest in exploring the biomechanical factors that may contribute to the development of foot disorders and the associated impairment of mobility in this age group. Studies have shown that with advancing age, there is a general tendency for the foot to exhibit increased soft tissue stiffness, a decreased range of motion, decreased strength and a more pronated posture as well as to function in a more pronated position with reduced joint mobility and less efficient propulsion when walking. These changes may contribute to the development of foot pain, impair performance in functional weight-bearing activities and increase the risk of falls. However, plantar pressure analysis technology has considerable potential to assist in optimising the design of interventions to redistribute load away from high-pressure areas, thereby alleviating foot symptoms and improving mobility in older people.
Topics: Aging; Foot; Foot Joints; Humans; Posture; Range of Motion, Articular; Walking; Weight-Bearing
PubMed: 25402236
DOI: 10.1159/000368357