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Excessive muscle tone or stiffness secondary to stroke frequently involves the ankle plantarflexors and has been associated with decreased mobility and reduced function. Although becoming more common in clinical practice, the effectiveness of botulinum toxin A (BTX-A) injected in the ankle plantarflexors on gait biomechanics is not well established. The primary objective of this study was to describe the kinematic and kinetic changes that occur during walking following BTX-A treatment of the hypertonic ankle plantarflexors. As well, the study explored whether there were clinical characteristics uniquely associated with subjects that exhibited biomechanical improvement. The study was a single group, open label trial with repeated measures, including multiple baseline and three post-intervention time points. Seven chronic hemiparetic stroke subjects with ankle hypertonicity were included in the study. Full lower limb bilateral gait analysis provided joint kinematic and kinetic information throughout stance. As well, clinical measures of ankle range of motion and spasticity were assessed pre and post treatment. Data were analyzed using paired samples t-tests and repeated measures ANOVA with Least Significant Difference adjustment for post-hoc analysis as necessary (significance level p≤0.05). Of the kinematic variables, significant improvements in peak dorsiflexion and plantarflexion and the ankle angle at initial contact were found 10 weeks post-injection relative to baseline. No significant kinetic changes were detected, however 2 subjects showed improved positive work at the ankle post-injection and 5 subjects demonstrated increased positive work at the hip post-treatment. Although subjects were classified as “responders” or “non-responders” based on clinical improvement observed 2 weeks post-injection, there was no observable association between those who responded clinically and those who demonstrated improved gait. The major findings suggest that BTX-A injection results in tone reduction and in some cases improves the biomechanical efficiency of gait. In cases where kinetic variables remained unchanged following treatment, perhaps the increased tone was not the limiting factor of reduced function. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2007-08-30 09:41:03.24

Acute stretching increases postural stability in nonbalance trained individuals. J Strength Cond Res 26(11): 3095-3100, 2012-Studies into the relationship between acute stretching and maintenance of postural balance have been inconclusive. It was hypothesized that familiarization with the task and subsequent learning might be involved in the conflicting results. Therefore, this study was to designed determine if a regimen of static stretching exercises after a familiarization period would improve a person's ability to maintain a stabilometer in a neutral position and whether stretching had the same effect on individuals with extensive involvement with balancing tasks. Forty-Two college students (21 male, 21 female) and 10 surfers (all male) performed tests on a stabilometer on 2 separate days after 3 days of familiarization. Testing followed either 30 minutes of quiet sitting (nonstretched) or 30 minutes of stretching activities (stretched). Stretching exercises consisted of various assisted and unassisted static stretches of the muscles around the hip, knee, and ankle joints. Improved flexibility after the stretching exercises was demonstrated by significant (p , 0.05) 6.5 6 2.7 cm (mean 6 SD) increase in the sit and reach. Balance time for the students improved significantly by 11.4% (2.0-second increase), but the surfers had no significant change. Thus, stretching improved maintenance of balance perhaps by helping the subjects to eliminate the gross muscle contractions that caused large stabilometer displacements and to replace them with fine muscle contractions that caused little or no stabilometer displacements. However, it appears that experience doing balance tasks supplants any stretching benefit.

京都大学 / 0048 / 新制・課程博士 / 博士(人間健康科学) / 甲第22387号 / 人健博第73号 / 新制||人健||5(附属図書館) / 京都大学大学院医学研究科人間健康科学系専攻 / (主査)教授 黒木 裕士, 教授 山田 重人, 教授 松田 秀一 / 学位規則第4条第1項該当 / Doctor of Human Health Sciences / Kyoto University / DFAM

<p>The purpose of this thesis was to evaluate musculoskeletal contributions to joint stiffness in the distal upper extremity. An <em>in-vitro</em> and <em>in-vivo</em> approach was used to examine muscle and ligament contributions to mechanical joint stiffness at the elbow and wrist. In Chapters 2 and 3 an <em>in-vitro</em> approach was used to evaluate ligament contributions to carpal tunnel mechanics. Chapter 2 documented transverse carpal ligament (TCL) mechanical properties and provided a calculation of TCL length when stretched, which confirmed the ligaments importance in carpal tunnel mechanics and carpal bone stability. Chapter 3 quantified mechanical properties of the TCL at six different locations using a biaxial tensile testing method. It was found that the complex TCL fibre arrangement makes the tissue properties location dependent. The TCL contributes to carpal tunnel mechanics and carpal stability and the ligament contributions are different depending on the tissue location tested. Chapters 4 and 5 focused on the effects of hand loads and arm postures on the muscular response to sudden arm perturbations. The elbow flexors demonstrated stiffness contributions immediately prior to a perturbation and were influenced by posture and hand loading. The forearm muscles provided a small contribution to elbow joint stiffness. Chapter 6 also found muscular contributions that increased wrist joint stiffness immediately prior to a sudden perturbation. Additionally, for a small grip-demanding task, forearm muscle co-contraction resulted in large increases in wrist joint stiffness.</p> <p>This thesis has provided a detailed analysis of the TCL which improves our understanding of the carpal tunnel and specific mechanisms of injury. It is the first to document individual muscle contributions to elbow and wrist joint stiffness. The comprehensive analysis of ligament and muscular contributions to joint stiffness has provided insight into joint stability in the distal upper extremity. This can improve our understanding of injury caused by sudden joint loading.</p> / Doctor of Philosophy (PhD)

Laser Doppler Vibrometry (LDV) is a non-contact technique for sensing surface vibrations. Traditionally, LDV uses one or more fixed beams to measure the vibrational velocity of specific points and orientations. In order to measure an angular velocity at least two laser beams are required. Instead, this research proposes to develop a Continuous Scanning Laser Doppler Vibrometer (CSLDV) technique, based on a single laser beam continuously sweeping the area of interest using a scanning mirror. Linear scans allow the measurement of normal and angular velocity while circular scans allow the measurement of normal velocity and two angular velocities. The first part of the study analyzes the performance of rigid body models of both the short line and circular scans (< 1 cm) for measuring low broadband frequency vibrations of gel samples. This thesis focused on low frequency broadband vibration since natural human body vibrations (such as tremor or breathing) are typically below a few hundred hertz. Results for normal and angular velocity measurements are validated against conventional method of using two fixed LDVs. The second part of this research investigates the CSLDV technique for longer scans (< 5 cm). These long scans will be used to act as an array of virtual transducers at multiple points along the scanning path of the single laser beam; thus yielding similar information obtained using an array of several real fixed LDVs. A practical challenge encountered when using CSLDV is speckle noise, that is generated when a coherent light source is reflected back from an optically rough surface. The effect of speckle noise will be quantified by varying different parameters such as scan lengths, scanning frequency, target to sensor distance and the amplitude of excitation. These parameters will be optimized in order to reduce the error of vibration measurements obtained from the CSLDV. Such systems will be used to monitor multiple degrees of freedom of human skeletal muscle vibrations for elastography purposes. The forced vibration of human muscles will be analyzed using these CSLDV techniques. Overall contributions of this work include: (1) Validation of rigid body models of both short line and circular scans CSLDV for broadband low frequency linear and angular velocity measurements; (2) application to sensing natural human body vibrations (e.g., hand tremors); (3) replacement of an array of vibration sensors by a single long line scan CSLDV. (4) development of a dynamic elastography technique for skeletal muscles using CSLDV.