Fast medio-lateral movements, frequent in a number of sports activities, are associated with lower extremity injuries. These injuries may occur as a result of excessive musculoskeletal stresses on the joints and their associate structures. The purpose of this study was to investigate the effect of running speed and turning movement on the three-dimensional moments at the ankle, knee, and hip joints. Data were collected using video cameras and force plate. Eight male recreational basketball players were tested during slow (1.5 m/s), moderate (3.0 m/s), and fast running (4.5 m/s) and when cutting to the right or left (+60, +30, 0, -30, and -60��). The inverse dynamics approach was used to integrate the body segment parameter, kinematic and force plate data, and to solve the resultant joint moments. At the ankle joint, inversion/eversion, dorsi/plantar flexion, and internal/external rotation moments of the ankle joint increased with running speed (p<.05). At the knee joint, flexion/extension and abduction/adduction moments increased with running speed except flexion moment that decreased with running speed (p<.05). At the hip joint, internal/external rotation, flexion/extension, and abduction/adduction moments increased with running speed (p<.05). In medial cutting movements, greater abduction moments of the ankle, adduction moments of the knee and external rotation and adduction of the hip were found (p<.05). In lateral cutting movements, greater inversion and adduction moments of the ankle, abduction moments of the knee and hip were found (p<.05). These findings reinforce the intuitive notion that fast medio-lateral turning movements produce substantially greater musculoskeletal loading on the joint structures than does straight running and consequently have greater potential for inducing lower extremity injuries such as ankle sprain or anterior cruciate ligament injury. / Graduation date: 1999

Femoroacetabular impingement (FAI) has been increasingly recognized as a cause of early hip osteoarthritis. FAI is characterized by pathologic contact between the femur and acetabular rim during hip join movement, caused by morphological abnormalities. Arthroscopic technique has become increasingly popular for FAI surgical treatment because of its minimal invasiveness. However, it involves cumbersome procedures and over- or under-resection are likely to occur. To tackle this issue, robot-assisted FAI arthroscopy is a well suited approach because it results in high accuracy and reproducible surgical outcomes. This dissertation provides new approaches and methods for the current challenges in the development of robot-assisted FAI arthroscopy. The study has three objectives: 1) to develop a robust calibration method for the A-mode ultrasound probe used for noninvasive bone registration, 2) to develop a bone registration simulator for verifying the registration accuracy and consistency for any given registration point-pattern, and 3) to develop a hip range of motion simulation system that returns the virtual range of motion and determines the bone resection volume. Carefully designed calibration procedures and simulation experiments have been conducted during the study of this research. From the experimental results, the developed ultrasound calibration method successfully reduces the registration errors and is proved to be robust. The results from the registration simulator indicate that the pattern with widely distributed points lead to better registration accuracy and consistency. The hip range of motion simulation system results in acceptable accuracy and successfully generates the resection volume. With further modifications, the ultrasound probe can be successfully calibrated with the developed method, and will be applied for noninvasive bone registration. The registration simulator can also be served as a useful tool for determining the optimized registration point-pattern, which can lead to reduced surgical trauma and registration time. Finally, the developed range of motion simulation system can allow the surgeon to evaluate the surgical outcome and to determine the resection volume even before the surgery begins. To conclude, this dissertation provides useful approaches, methods, and software for developing robot-assisted FAI arthroscopy.

Snowboarding is a relatively young sport and has grown since the birth in the 1960-70. Today, snowboarding still is a lifestyle to many, but also an accepted mainstream sport and has been an Olympic sport since the Olympic Winter Games in Nagano, Japan 1998 (18,35,36). The movement pattern and body position is asymmetric, since you stand sideways with the front foot ahead of the rear foot in the line of direction (14,18,28). Several studies that have investigated the biomechanics of snowboarding have showed that the loading of the lower extremities are different in the front leg compared to the rear leg during riding (14,18, 22,23,28). The purpose of this study was to investigate if the asymmetric body position in snowboarding causes differences between front and rear leg considering; circumference of thigh, range of motion (ROM) in the hip joints, power in lower extremities, or causes asymmetrical ROM in the spine in the test group compared to the control group. Two groups were used, one test group consisting of ten elite snowboarders (n=10) with an average age of 18 years, and one control group consisting of eight high level skiers (n=8), average age 17,25 years. All subjects were students at Malung/Sälen Alpine Elite Gymnasium. Measurements of ROM in hip and spine were made with a myrin incline goniometer and universal plastic goniometer. A one leg countermovement jump (CMJ) was made as a test of power in the lower extremities using Ivar ump &amp; speed analyzer. Measurements of circumference of thighs were made using a soft tape measure. The results show significant differences in four of the ten measurements in test group and in two of the ten measurements in the control group. There are significant differences in hip passive flexion (P&lt;0,05) and adduction(P&lt;0,05) in both groups (Tables 2,3) suggesting that in these movements there are individual differences. The one leg CMJ and circumference of thigh shows significant differences, (P&gt;0,05) and (P&lt;0,001), between front and rear leg in the test group (Table 2), but no such differences can be seen in the control group (Table 3) suggesting that these differences may be caused by the asymmetrical body position during snowboarding.

Reverse shoulder arthroplasty (RSA) is a joint replacement procedure used mainly to treat patients with severe shoulder osteoarthritis combined with massive rotator cuff tears. It involves reversing the `ball and socket' orientation of the glenohumeral joint in the shoulder. While RSA has been largely successful in treating pain and improving function in these patients, complication rates remain high. Many of these complications, including joint instability and scapular notching (excessive bone wear), are caused or exacerbated by impingement of the humerus or the humeral component against the scapula. Adduction deficit refers to a patient's inability to fully adduct the arm due to impingement. Minimizing adduction deficit may improve RSA patients' functional outcomes. An existing mechanical shoulder simulator was further developed to model glenohumeral range of motion in RSA. The three heads of the deltoid were modelled using polyethylene cable and electric linear actuators with inline load cells. RSA components were implanted in Sawbones scapula and humerus bone models. The scapula was fixed in the frame of the simulator. Triads of optical tracking markers were attached to the humerus and simulator frame and used to track segment motion. A data analysis technique was developed to determine when joint impingement occurred. The convex and concave surfaces of the glenoid and humeral components were digitized, and a least-squares sphere fit was used to find their centres. The distance between these centres was then calculated during passive abduction and adduction of the humerus, and labeled d_GH. Impingement onset was defined as the point where d_GH was five standard deviations above its baseline value, indicating that the components were no longer concentric. This technique was used to determine the effects of humeral neck-shaft angle, socket depth, glenosphere diameter and eccentricity on range of motion and adduction deficit. A retentive humeral cup depth increased adduction deficit by 14 degrees and reduced range of motion by 26 degrees. A decreased neck-shaft angle reduced adduction deficit by 10 degrees but had little effect on overall range of motion. Diameter and eccentricity had no effect on either measure. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2014-04-03 13:34:07.404

The purpose of this dissertation was to analyze shoulder joint kinematics and electromyographic activities of wheelchair propulsion between two stroke patterns. Twenty physical therapy students (14 females and 6 males, age 27.4 ± 5.9 years, body mass 64.41 ± 9.37 Kg and body height 169.32 ± 9.12 cm) participated. Eleven reflective markers were placed on thorax and right scapula, humerus, third metacarpophalangeal joint and wheelchair axle. Surface electrodes were placed on right pectoralis major, anterior and posterior deltoids, infraspinatus, middle trapezius, biceps brachialis long head and triceps brachialis. Participants propelled a standard wheelchair on a stationary roller system at 0.9 m/s and 1.8 m/s with semicircular (SC) and single loop (SL) stroke patterns for 20 seconds. Three-dimensional body movement and muscle activities were recorded at 100 and 1000 Hz, respectively. All data were compared for differences between two patterns and two speeds using 2-way repeated measures ANOVA (α < .05). Results showed longer drive phase and shorter recovery phase in SC when compared to SL, with no difference found on cycle time. Smaller release angles in SC caused longer angle ranges of hand contact on the pushrim while initial contact angles did not change. During drive phase, smaller scapular protraction range of motion (ROM) was found in SC. Shoulder abduction in drive phase was larger in terms of the maximal angle and ROM. In the recovery phase, minimal scapular tilting, protraction, and shoulder abduction and internal rotation were larger in SC when compared to SL pattern. Shoulder linear velocities and accelerations were higher in both phases for abduction/adduction and flexion/extension in SC. For SC pattern, pectorals major and middle trapezius showed lower activities during drive phase while posterior deltoid and triceps showed higher activities during both phases when compared to SL. Although posterior deltoid and triceps muscles work harder in SC pattern, longer drive phase and lower muscle activities in pectorals major and middle trapezius during the drive phase may make SC the better stroke pattern in wheelchair propulsion when compared to SL.

The present study quantifies electromyographic variables in one and two degree of freedom elbow movements involving flexion/extension and pronation/supination, in order to understand the associated central commands. Agonist burst magnitude varied with motion in a second degree of freedom for some muscles but not for others. In movements for which a biarticular muscle acted as agonist in two degrees of freedom, agonist burst magnitudes were approximately the sum of the magnitudes in the component movements. Agonist burst magnitude varied with motion in a second degree of freedom for some, but not all, monoarticular muscles. When biarticular muscles acted as agonist in one degree of freedom and antagonist in the other, the muscle often displayed both components simultaneously. The additivity of EMG burst magnitudes in two degree of freedom movements and the presence of both agonist and antagonist bursts in a muscle suggest that central commands associated with motion in individual degrees of freedom are superimposed in producing two degree of freedom movements.

Femoro-Acetabular Impingement (FAI) is a hip joint disease which affects and impairs the range of hip motion during performing activities of daily living, jogging, walking, or climbing stairs due to the bony abnormalities of the joint. Ballet dancers and athletes (e.g. gymnasts and hockey players) put their hips at the risk of FAI by extremely moving the hip mainly by excessively rotating the joint. In this research, we introduce a visualization system which helps surgeons to analyze the range of hip motions as well as to have a better communication with patients. These goals are achieved by presenting three dimensional (3D) visualizations of motion envelope by examining the maximum possible rotation of the digital hip bones. Our computer simulation system estimates, analyzes and visualizes the maximum hip range of motion (ROM) for the constructed 3D bone models that are extracted from Magnetic Resonance Images (MRI) after segmenting the bones. These tasks are accomplished by first calculating Hip Joint Center (HJC) which is center of rotation of femoral head on the 3D segmented MRI models followed by simulating hip motions with examining impingement between the femur and the acetabulum using our collision detection system. In our collision detection system, surfaces of femoral head and acetabulum bones are sampled in the spherical coordinates based on rasterization and interpolation. Then, the distance between the femoral head and acetabulum are computed to prevent impingement between them. The maximum motion degree of femur bone within depression of acetabulum in every direction during the digital simulation shows the ROMs of the inputted MRI of the hip joint. Six primary plane motions (flexion/extension, abduction/adduction and internal/external rotation) as well as various combinations of these motions (maximum rotation of the hip between every two rotational movements) and successive movements (maximum rotational movement of the hip per another rotational movement) are simulated and analyzed along with 3D visualization of estimated range of these motions. Generally, the ROM differs by some factors such as age, gender, ethnicity, and geographic location. For instance, newborns up to age two have considerably greater motion in hip flexion and hip abduction than adults. Our system by 3D visualization of motion envelope will provide a platform to understand quicker and better the effect of bony morphology of the hip joint on the possible ROM. We also examine the long-standing question about moving center of rotation related to ROM. We found out the ROM becomes bigger especially when the center moves outward to the direction of acetabulum axis. This thesis does not consider the effect of muscle and other surrounding connective tissue on the hip ROM since they can be altered significantly by physical training to show the potential of maximum ROM. For example a ballerina has a bigger ROM leading a bigger motion envelope compared with non-dancers. Hence we visualize the range of joint motions and their envelopes that are obtained from the osseous anatomy of the hip joint. The osseous anatomy of the joint is the most fundamental and permanent factor of ROM which indicates the maximum motion that the joint can achieve if the muscle and other connective tissues are perfectly trained.

Thesis (M.S.)--University of Tennessee Health Sciences Center, 2005.

M.Tech. / Soccer is the most widely played sport in the world and, of all the skills required to participate, the instep soccer kick is considered to be the primary offensive action within the game of soccer. Biomechanical analysis of the instep soccer kick has revealed that the action of kicking is characterised by a proximal to distal series of multi-articular movements with distal segmental movements being predetermined by more proximal ones (Kellis and Katis, 2007). According to Smith, Gilleard, Hammond and Brooks (2006), the lower spine and pelvis play a pivotal role in determining the placement and actions of distal segmental motion during the action of the instep soccer kick. The aim of this study was to determine the effectiveness of chiropractic adjustments in soccer players with lumbar facet and sacroiliac joint dysfunctions by assessing the resultant speed of a soccer ball once kicked with an instep soccer kick. By correcting the lumbar facet and sacroiliac joint dysfunction of the affected soccer players, it was postulated that with restoration of joint motion and reduction of pain, the speed of the soccer ball, when kicked, would improve. When kicked the resultant ball speed is indicative of biomechanical kicking success. Thirty male professional soccer players from the Jomo Cosmos football establishment who met the study’s selection criteria were selected and randomly divided into one of two groups. The study group received chiropractic adjustments of dysfunctional lumbar facets and sacroiliac joints and the control group received a placebo treatment in form of a de-tuned stationary ultra-sound head over the effected facets joints for five minutes. Treatment for both groups occurred over a two week period with treatment being administered twice a week, totalling of four treatments per participant. Data capture was collected 3 times over the 2-week period; 1st reading done before the 1st treatment, the 2nd reading before the 3rd treatment and the final reading taken after the 4th and final treatment. Data capture consisted of both subjective and objective readings. The subjective data consisted of the measurements of pain experienced by the participants in the form of a Numerical Pain Rating Scale. Objective data involved the measurement of ball speed once kicked, with the use of a radar speed gun as well as lumbar spine range of motion measurements by means of a Digital Inclinometer. In executing the group comparisons, it was found that both groups would present with contrasting results. The group undergoing the chiropractic adjustments would show an improvement in their ball speed, reduction in their overall pain and increased lumbar spine extension and rotation ROM; where as the group undergoing the placebo treatment experienced a decrease in their ball speed, an increase in their overall pain and decreased lumbar spine ROM. The results obtained from the study demonstrated that the majority of the data was not statistically significant in either of the groups however, from a clinical perspective there was a definite effect on the lumbar spine range of motion, ball speed and pain reduction as a result of the Chiropractic adjustments that would warrant further investigation. There is a definite link with the negative effects that lumbar facet and sacroiliac joint dysfunctions have on the proximal to distal sequence of events that take place during the instep soccer kick. Therefore, treating the lumbar facet and sacroiliac joint dysfunction with chiropractic adjustments allows for better transfer of energy between segments and for greater resultant ball speed. In conclusion, the study demonstrated that chiropractic adjustment of lumbar facet and Sacroiliac joint dysfunctions showed good improvement in the resultant ball speed, reduction in lower back pain and improved lumbar spine extension and rotation ROM. From these results, it would be prudent to incorporate more chiropractic treatment into mainstream soccer and encourage further research into the advantages that chiropractic treatment has in better understanding the biomechanics involved in the instep soccer kick.

M.Tech. (Chiropractic) / Purpose: This study aims to ascertain the extent Chiropractic manipulative therapy increases ROM beyond the joint-separation induced ROM initially experienced via the cavitation phenomenon in the absence of neck pain. Method: Sixty participants between eighteen and thirty-five years of age, thirty male and thirty female whom met the inclusion of no neck pain and perceived decreased ROM were selected for participation. There was a single group with each participant‟s pre-adjustment readings acting as a baseline. Procedure: Participants were assessed for hypomobility and joint dysfunction. Those who met the inclusion criteria underwent a detailed history, physical and cervical spine regional examination on the initial consult. A pre-adjustment objective measurement was acquired using a cervical spine range of motion (CROM) device. Once the consent form was signed participants received Chiropractic cervical spine manipulative therapy to the area/s of the cervical spine found to be restricted on motion palpation by the researcher. Post-adjustment objective measurements were taken at one, twenty, forty and sixty minutes using the CROM device. Participants were required to remain in the researcher‟s examination room for 60 minutes post-adjustment with continuation of regular day to day activity and no strenuous activity during the twenty-four hour period of the study. The participant was required to return for a single follow up visit within a time frame of twenty-four hours of the initial visit. The follow-up visit required no treatment. At twenty-four hours, the participant was objectively measured for cervical spine ROM using the CROM. The results were based on objective data in the form of cervical spine ROM measurements. Results: Clinical analysis of the percentage change in cervical spine ROM values revealed that clinically and statistically significant improvement was seen in all ranges of motion post-adjustment. General consensus showed that a peak value of improved ROM was seen post-adjustment at the one minute interval for all ranges of motion except flexion. Flexion demonstrated a peak ROM value at the twenty minute post-adjustment interval.