Osteoarthritis is the most common form of arthritis. Genetic models have been developed to determine if and how a targeted gene may influence cartilage degenerative changes. The itga1-null mouse model has an inhibited integrin α1B1 through a ubiquitous integrin α1 subunit knockout, which leads to fibrosis in articular cartilage through excessive signalling from transforming growth factor beta (TGFB). Depleting this TGFB signalling is proposed to have a protective effect on cartilage. This project is part of a foregoing study where a cartilage-specific knockout of TGFB receptor type II (TBRII) was used to deplete TGFB signalling in articular cartilage of the itga1-null mice to reduce the severity of cartilage degradation. This project continues the analysis of the genetic model into bone architecture at the knee. Mouse hindlimbs were scanned at a 13μm resolution using micro-computed tomography and segmented into 3D datasets containing calcified tissues and bone of the knee and surroundings. Quantification methods for trabecular bone parameters (bone volume fraction, trabecular separation, and trabecular thickness) and ectopic calcification of soft tissues were developed. Loss of trabecular bone around the involved joint is a hallmark of post-traumatic osteoarthritis. However, the results from this study showed no significant changes in trabecular bone of itga1-null mouse knees despite observing severe osteoarthritic changes in the adjacent cartilage. There were no significant effects in peri-articular trabecular bone when the TBRII knockout in cartilage was activated, but there were significant increases in ectopic calcifications of the menisci and collateral ligaments. These ectopic calcifications were also seen in tamoxifen control mice, suggesting that tamoxifen, along with TBRII depletion in cartilage, had a role in increased abnormal calcifications. Although integrin α1B1 inhibition appears to have an important role in cartilage degeneration, it does not appear to influence the bony changes that normally accompany post-traumatic arthritis. / Thesis / Master of Applied Science (MASc) / Osteoarthritis is a common joint disorder, associated mainly with cartilage degradation. Some genes have been identified that cause or prevent osteoarthritis. A previous study used two of these genes in a genetic mouse model to explore how osteoarthritis may develop. Removing the integrin α1 subunit from mice caused osteoarthritic changes in the cartilage of the mouse knee. When the transforming growth factor beta gene was removed from the cartilage, these changes were less severe. This project continued the study by exploring changes in bone around the mouse knee. We quantified bone changes around the mouse knee using high-resolution micro-computed tomography scans. Contrary to common findings in post-traumatic osteoarthritis, we found that there were no significant changes in the bone around the knees even where severe cartilage changes had been identified. However, there were significant increases in calcifications of soft tissues including the meniscus and ligaments around the knee.

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In 1968 a number of Chippewa Indians met in Minneapolis, Minnesota to discuss some of the problems they faced in their communities. This meeting gave birth to the American Indian Movement. From 1968 to 1974, the American Indian Movement embarked on a series of radical protests designed to draw attention to the concerns of American Indians and force the Federal government into acting on their behalf. Unfortunately, these protests brought about a backlash from Federal law enforcement agencies that destroyed the American Indian Movement's national power structure.

In the sport of track and field, sprinting and distance running represent two major categories of athletes. Sprinting is associated with power and speed, whereas distance running focuses on the economy of movement. With distance running there are elements of sprint technique that overlap. With distance events, there comes a time near the end of the race where economy gives way to speed. If the distance runners knew how to alter their technique in a way to become more sprint-like, this process could possibly be more successful. PURPOSE: This study compared the differences in technique between sprinters and distance runners while running at equal and maximal speeds. METHODS: Subjects for the study consisted of 10 Division I collegiate distance runners, 10 Division I collegiate sprinters, and 10 healthy non-runners. The subjects performed two tests, with each consisting of a 60 meter run completed on the track. Test 1 was run at a pace of 5.81 m/s (4:37 min/mile), while Test 2 was completed at maximal speed. Video footage of each trial was collected at 180 Hz, monitoring hip, knee, thigh, and shank positions, as well as stride length, and contact time. RESULTS: Significant differences (p < .05) between the sprint and distance groups at maximal speed were found in the following areas: speed, minimum hip angle, knee extension at toe-off, stride length, contact time, and the position of the recovery knee at touchdown. Sprinters and distance runners exhibited a significantly lower minimum knee angle than those in the control group. Significant differences between the sprint and control group existed at the minimum hip angle, speed, stride length, contact time, and the position of the recovery knee at touchdown. Regarding the paced trial, the sprinters and distance runners showed significant difference concerning the minimum hip angle, center of mass at touchdown, and recovery knee at touchdown. Sprinters differed significantly from the control group in contact time, the center of mass at touchdown and the position of the recovery knee at touchdown. CONCLUSION: As distance runners attempt to sprint, the desired adaptations do not necessarily occur. The development of economical distance form is a fairly natural process that occurs with the miles of training. Sprinting, however, is a separate, learned technique that often requires specific feedback. When attempting maximal speed, distance runners may benefit by focusing on one characteristic of technique. If knee extension at toe-off could be trained to become more sprint-like, the other characteristics unique to sprinters may follow.

The purpose of the present study was to compare total knee arthroplasty (TKA) rehabilitation with and without whole-body vibration (WBV) to 1) understand if WBV is a useful treatment during TKA rehabilitation to increase quadriceps strength and function, and 2) to investigate the effect of WBV on quadriceps voluntary muscle activation. Subject and Methods. Individuals post TKA (WBV n=8, control n=8) received physical therapy with and without WBV for four weeks. Quadriceps strength and muscle activation, function, perceived pain, and knee range of motion were measured. Results. No adverse side effects were reported in either group. There was a significant increase in strength and function for both groups (P<0.01). There was no difference pre to posttest between groups for strength, muscle activation, or pain (Hotelling’s T2=0.42, P=.80) or for function (F=0.54, P=0.66). Discussion and Conclusion. In individuals with TKA, WBV showed equal strength and function improvement to physical therapy directed progressive resistive exercise. Influence of WBV on muscle activation remains unclear, as initial muscle activation was near established normal quadriceps levels and remained so post treatment.

Context: Knee pain is experienced by many people. Because of this, authors have started researching the effects of pain on lower extremity mechanics and also on static and dynamic postural control. However, the effects of pain are difficult to study due to associated confounding variables. Objective: We asked: (1) Will experimentally-induced anterior knee pain alter perceived pain using the visual analogue scale? ; (2) will perceived pain affect postural control as measured by center-of-pressure during static and dynamic movement? Design: Crossover. Setting: Biomechanics laboratory. Participants: Fifteen healthy subjects. Intervention: Each subject participated in single leg quiet stance, landing, and walking trials under three conditions (pain, sham, control), at three different times for each condition (pre-injection, injection, and post-injection). Main Outcome Measures: The dependent variables were measured at pre-injection, injection, and post-injection. Pain was measured using the visual analogue scale across all three times during each condition. Center-of-pressure sway was measured during single leg quiet stance to calculate the average center-of-pressure velocity in the anterior-posterior and medial-lateral directions. The center-of-pressure time to stabilization was measured in anterior-posterior, medial-lateral, and vertical directions, and center-of-pressure trajectory excursion was measured in the medial-lateral direction during walking. Results: Perceived pain was significant (P < 0.05) but did not affect postural control as measured by center-of-pressure medial-lateral and anterior-posterior sway during single leg quiet stance, in time to stabilization during landing, and in medial-lateral excursion during walking. Conclusions: Injection of hypertonic saline resulted in statistically significant perceived pain but did not affect postural control as measured by center-of-pressure medial-lateral and anterior-posterior sway during single leg quiet stance, in time to stabilization during landing, and medial-lateral excursion during walking.

Knee pain can alter lower-extremity neuromechanics and often results in functional disability. The relationship between lower-extremity neuromechanical alterations, due to anterior knee pain, and articular cartilage condition is unclear. The purpose of this study was to determine the independent effect of anterior knee pain during running on articular cartilage condition, as reflected by serum cartilage oligomeric matrix protein concentrations and muscle cocontraction duration. Seven men and five women completed a 30-min run in three different sessions: control (no infusion), sham (isotonic saline infusion), and pain (hypertonic saline infusion). Saline was infused into the right infrapatellar fat pad for the duration of the run. Subject-perceived pain was recorded every 3 min on a 100-mm visual analog scale. During the run, bilateral electromyography was recorded for five leg muscles, and heel and toe markers were used to track foot position. During the 30-min run of the pain session average subject-perceived pain was 27.8 (SD = 2.3 mm) and 19.7 (SD = 1.9) mm greater than during the control (0.0 mm) and sham (8.1 mm) session, respectively (p < 0.01). Knee pain while running did not result in changes in muscular cocontraction duration (p = 0.13). Blood samples were drawn prior to the run, immediately following the run, and 60 min following the run. Samples were analyzed using enzyme-linked immunosortbent assay to determine serum cartilage oligomeric matrix protein concentration. Average serum cartilage oligomeric matrix protein concentration was 14% greater at immediate post run (132.19 ± 158.61 ng/ml; Range = 22.61-290.81 ng/ml) relative to pre run (116.02 ± 118.87 ng/ml; Range = 19.81-234.89 ng/ml) (p < 0.01), and 18% less at 60 min post run (108.45 ± 171.78 ng/ml; Range = 20.84-280.23 ng/ml) relative to immediate post run (Figure 4; p < 0.01). Serum cartilage oligomeric matrix protein did not significantly differ between baseline and 60 min post-exercise (p = 0.29). There was not a difference in cartilage oligomeric matrix protein concentration between sessions. Knee pain while running does not cause an increase in serum cartilage oligomeric matrix protein concentration (p = 0.29). There are two important findings from this study. First, anterior knee pain during a 30 min running session does not appear to independently affect cartilage oligomeric matrix protein concentrations. This implies other factors, aside from anterior knee pain alone, influence articular cartilage degradation during movement that occurs while individuals are experiencing anterior knee pain. Second, the present experimental anterior knee pain model can be used to evaluate the independent effects of anterior knee pain over an extended duration while subjects perform a dynamic activity like running.

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Bakgrund En handhållen dynamometer (HHD) är ett kliniskt användbart mätverktyg för att mäta muskelstyrka. På Akademiska sjukhuset i Uppsala finns en HHD av märket MicroFET2® (Hoggan Scientific). Det finns ett fåtal studier gjorda som undersöker intrabedömarreliabiliteten vid mätningar av isometrisk muskelstyrka av knäledens muskelgrupper med denna dynamometer. Syfte Syftet med studien var att undersöka den absoluta och relativa reliabiliteten vid mätningar av maximal muskelstyrka i knäledens muskelgrupper med en HHD. Metod Psykometrisk design med test-retest förfarande. Totalt undersöktes 24 friska vuxna vid två mättillfällen med 6–8 dagars mellanrum. Den relativa reliabiliteten presenterades med Intraclass correlation coefficient (ICC 2,1). Den absoluta reliabiliteten presenteras i standard error of measurement (SEM), SEM% samt smallest detectable change (SDC). Resultat Resultaten visade mycket hög relativ reliabilitet för knäledens extensioner (ICC = 0,950,96) och för knäledens flexorer (ICC = 0,94–0,96). SEM varierade mellan 33,58N-34,81N för knäledens extensorer och 14,16N-17,16N för knäledens flexorer. SDC varierade mellan 93,08N–96,49N för knäledens extensorer och 39,25N-47,57N för knäledens flexorer. Konklusion Resultaten indikerar att HHD har mycket hög relativ reliabilitet för bedömning av styrka i knäledens stora muskelgrupper hos ett bekvämlighetsurval med friska vuxna människor.  Den relativa och absoluta reliabiliteten bedömdes överlag vara i enlighet med tidigare studier. För implementering i klinik behöver framtida studier utvärdera absolut och relativ reliabilitet på specifika patientpopulationer. / Background Hand held dynamometry (HHD) is a practical device for testing muscle strength. There is currently a HHD (MicroFET2® - Hoggan Scientific) available at Uppsala University hospital. Few reliability studies excist where the objective is to examine the intra-rater reliability of isometric maximal knee-strength using this device. Objective To examine the absolute and relative reliability of isometric maximal knee-strength using a MicroFET2. Method Psychometric design through test-retest with 6–8 days between measures on 24 healthy adults. The relative reliability expressed as Intra-class correlation coefficient (ICC 2,1) and the absolute reliability as standard error of measurement (SEM), SEM%, and smallest detecatble change (SDC). Results The results of this study showed very good reliability for both knee extensors (ICC = 0,950,96) and knee flexors (ICC = 0,94–0,96). Regarding the absolute reliability SEM ranged from 33,58N-34,81N for knee extensors and 14,16N-17,16N for knee flexors. SDC ranged from 93,08N-96,49N for knee extensors and 39,25N-47,57N for knee flexors. Conclusion The results indicate that HHD has a very good relative reliability for assessing strength in the large muscle groups of the knee joint when examined on a group of healty adults. The relative and absolute reliability was generally in accordance when compared with previous studies. Before being implemented in praxis, future studies need to evaluate absolute and relative reliability on specific patient populations.