Rate Of Joint Loading Research Articles

Reduced step length reduces knee joint contact forces during running following anterior cruciate ligament reconstruction but does not alter inter-limb asymmetry

BackgroundAnterior cruciate ligament reconstruction is associated with early onset knee osteoarthritis. Running is a typical activity following this surgery, but elevated knee joint contact forces are thought to contribute to osteoarthritis degenerative processes. It is therefore clinically relevant to identify interventions to reduce contact forces during running among individuals after anterior cruciate ligament reconstruction. The primary purpose of this study was to evaluate the effect of reducing step length during running on patellofemoral and tibiofemoral joint contact forces among people with a history of anterior cruciate ligament reconstruction. Inter limb knee joint contact force differences during running were also examined. Methods18 individuals at an average of 54.8months after unilateral anterior cruciate ligament reconstruction ran in 3 step length conditions (preferred, −5%, −10%). Bilateral patellofemoral, tibiofemoral, and medial tibiofemoral compartment peak force, loading rate, impulse, and impulse per kilometer were evaluated between step length conditions and limbs using separate 2 factor analyses of variance. FindingsReducing step length 5% decreased patellofemoral, tibiofemoral, and medial tibiofemoral compartment peak force, impulse, and impulse per kilometer bilaterally. A 10% step length reduction further decreased peak forces and force impulses, but did not further reduce force impulses per kilometer. Tibiofemoral joint impulse, impulse per kilometer, and patellofemoral joint loading rate were lower in the previously injured limb compared to the contralateral limb. InterpretationRunning with a shorter step length is a feasible clinical intervention to reduce knee joint contact forces during running among people with a history of anterior cruciate ligament reconstruction.

Long-term effects of heavy metals and antibiotics on granule-based anammox process: granule property and performance evolution.

The feasibility of the anaerobic ammonium oxidation (anammox) process to treat synthetic swine wastewater containing antibiotics and heavy metals was studied in this work. Nitrogen removal performance and granule characteristics were tracked by continuous-flow monitoring to evaluate the long-term joint effects of Cu and Zn and of Cu and oxytetracycline (OTC). Cu and Zn with a joint loading rate (JLR) of 0.04 kg m(-3) day(-1) did not affect the performance, while a JLR of 0.12 kg m(-3) day(-1) caused a rapid collapse in performance. Cu and OTC addition with a JLR of 0.04 kg m(-3) day(-1) for approximately 2 weeks induced significant nitrite accumulation. Granule characteristic analysis elucidated the disparate inhibition mechanisms of heavy metals and antibiotics: the internalization of heavy metals caused metabolic disorders, whereas OTC functioned as a growth retarder. However, anammox reactors could adapt to a JLR of 0.04 kg m(-3) day(-1) via self-regulation during the acclimatization to subinhibitory concentrations, which had a stable nitrogen removal rate (>8.5 kg m(-3) day(-1)) and removal rate efficiency (>75 %) for reactors with Cu-OTC addition. Therefore, this study supports the great potential of using anammox granules to treat swine wastewater.

The relationship between knee joint loading rate during walking and degenerative changes on magnetic resonance imaging

BackgroundWhile animal study and cadaveric study have demonstrated an association between knee joint loading rate and joint degeneration, the relationship between knee joint loading rate during walking and osteoarthritis has not yet been sufficiently studied in humans. MethodsTwenty-eight participants (14 transfemoral amputees and 14 age and body mass matched controls) underwent knee MRI with subsequent assessment using the semiquantitative Whole-Organ Magnetic Resonance Image Score. Each subject also underwent gait analysis in order to determine knee adduction moment loading rate, peak, and impulse and an exploratory measure, knee adduction moment rate∗magnitude. FindingsSignificant correlations were found between medial tibiofemoral joint degeneration and knee adduction moment peak (slope=0.42 [SE 0.20]; P=.037), loading rate (slope=12.3 [SE 3.2]; P=.0004), and rate∗magnitude (slope=437 [SE 100]; P<.0001). These relationships continued to be significant after adjusting for body mass or subject type. The relationship between medial knee semiquantitative MRI score and knee adduction moment loading rate and rate∗magnitude continued to be significant even after adjusting for peak moment (P<.0001), however, the relationship between medial knee semiquantitative MRI score and peak moment was no longer significant after adjusting for either loading rate or rate∗magnitude (P>.2 in both cases). InterpretationThis study suggests an independent relationship between knee adduction moment loading rate and medial tibiofemoral joint degeneration. Our results support the hypothesis that rate of loading, represented by the knee adduction moment loading rate, is strongly associated with medial tibiofemoral joint degeneration independent of knee adduction moment peak and impulse.

Knee joint loading rate during walking and degenerative changes on MRI

Knee joint loading rate during walking and degenerative changes on MRI

Lower limb muscle strengthening does not change frontal plane moments in women with knee osteoarthritis: A randomized controlled trial

Background Osteoarthritis is a common musculo-skeletal problem accompanied with muscle weakness. Muscle weakness may be readily improved by resistance training. Greater muscle strength has been associated with a lower knee joint loading rate. Methods We conducted a single-blind randomized controlled trial of 54 female patients with osteoarthritis in at least one knee, according to the American College of Rheumatology clinical criteria. Patients were randomized into a 6-month high intensity progressive resistance training or a sham-exercise program. The primary outcomes were first peak knee and hip adduction moment measured using three-dimensional gait analysis at self-selected habitual and maximal speeds. Secondary outcomes were sagittal plane knee and hip moments, peak muscle strength, gait speed, and self-reported knee osteoarthritis symptoms measured by the Western Ontario and McMaster Osteoarthritis Index (WOMAC). Findings Six months of high intensity resistance training did not change the first peak knee or hip adduction moment at either habitual or maximum walking speeds ( P > 0.413) compared to the sham-exercise. However, the second peak hip adduction moment ( P = 0.025) and WOMAC pain score ( P < 0.001) were reduced significantly in both groups over time, but there was no group effect. The changes in the second peak hip adduction moment were inversely related to the changes in the WOMAC pain score ( r = − 0.394, P = 0.009). Interpretations Muscle strength training in women with osteoarthritis, while effective for reducing osteoarthritis symptoms, appeared to operate through mechanisms other than improved knee or hip joint loading, as paradoxically, improved symptoms were related to decreases of hip adduction moment in late stance.

Internal Loading of the Foot and Ankle during Impact in Running

A 3-D model was used in this study to determine the influence of midsole hardness, as well as the influence of running in shoes in comparison to barefoot, on the contact forces in the joints of the foot and ankle during running. The results showed that there were no statistical differences in the magnitude and rate of joint loading for changing midsole hardness, nor were there any general trends observed in the measured variables. However, both the magnitude and rate of loading in the subtalar and ankle joints during the impact phase were found to be greater in the barefoot condition than the shod condition. The results suggest that if running injuries are assumed to be related to the impact of heel-strike, running in shoes may aid in preventing injuries, whereas it is still questionable whether changes in the midsole hardness have a general influence on the incidence of impact-related injuries.