Design and Development of a Lower Limb Rehabilitation Device for Spinal Cord Injury Patients

Introduction: Spinal cord injuries (SCI) are seen commonly in Southern Africa and can completely change the course of the affected's life. Lower limb disability is a common complication from this injury, but a patient can be rehabilitated in some cases. Research and clinical observations suggest that early mobilisation and rehabilitation leads to shorter hospital stays and better clinical outcomes. Relieving the time dedication placed onto the rehabilitation team could mean that patients receive a higher standard of care. Methods: A cyclic movement device has been designed to mimic the gait cycle that a patient is attempting to recover. The device was intended towards providing a ground reaction force simulation at the correct points of the gait cycle. The device was tested in-silico with validated skeletal models to determine joint torques and angles. In-silico testing was also utilised to determine the loads placed onto the patient by the device through its use. The force data could then be used to predict possible ground reaction forces. Results: The device allows for a gait similar trace path of the ankle, comparable to that found in the literature. The ankle has a range of motion of 3 1° as the device completes a full cycle in which the crank rotates 360 °. The hip has a range of motion of 28° and the knee 35° in this same movement. The shape of the displacements of the joints of the lower limb is comparable to that seen in researched gait patterns. However, the timing of the knee and hip joints' movements are not synchronous with that of the gait patterns. The device is validated to be sufficiently stable to use, and the motor and power components can provide the 7259N.mm of torque needed to move the model. Conclusion: The results suggest that the device has potentia l as an adjunct to rehabilitation schemes. In-silico testing showed that the device is able to simulate some of the kinetic and kinematic parameters seen in normal gait. Further work is needed to prototype the device to physically and clinically validate the device

The potential for emulating the human footstrike using a Six Degrees-of-Freedom industrial robot

Part of the testing process for athletic footwear is exposing the shoes to realistic wear conditions; this can be in the form of user trials or, as is becoming more common place, the use of mechanical test devices. However, current mechanical test devices tend to be somewhat simplistic and fail to expose the footwear to the realistic loading environment. Thus, the aim of this thesis was to investigate the potential of using an off the shelf 6 Degrees-of-Freedom industrial robot to emulate the ground contact phase of human gait. This was achieved through addressing four research questions. The first research question aimed to outline the biomechanical features that were to be emulated and what their typical values were. Kinematics and kinetics of the real human gait were then collected, for use in programming the robot and evaluating its outputted movements. This was complemented by a comprehensive review of relevant literature. Previous investigations had highlighted the need for understanding of the robot s capabilities. This was taken further and input parameters such as level of robotic smoothing, programme velocity and the number of three dimensional co-ordinate points used were found to have an effect on the output kinematics of the robot. These features were also found to be part of the accompanying programme software (RoboGuide). Despite this, the differences were not identical and it was concluded that the software could only have a limited use in supporting the wider thesis aim. Prior to emulation, there was a need for robot set-up and its environment to be optimised. A new robot end-effector, with improved biofidelity, was developed which incorporated a new way of generating the robot motion that intended to aid kinetic and kinematic emulation. Further to this, analysis on robot movements in various locations identified the optimal location for the ground contact phase to be achieved. Using all of the gathered knowledge the robot was programmed to complete a footstrike for human walking using two types of programming method. When the robot is programmed directly with the human kinematic data the emulation of the footstrike is relatively poor; ground contact time is too long with an increased footprint size and poor ground reaction force profiles replication. Using a rotation about a fixed point on the footform led to improved, although not complete, emulation of the human gait parameters. The developed system has been shown to improve on previous work at Loughborough University and is also comparable with what is being used in industry and developed within academia. The concept remains in the early phases but the current study indicates that future work can move the robot further towards being able to produce a more biofidelic emulation that can be used in the footwear testing industry

The Effect of Football Boots on the Structure and Function of the Midfoot and the Relationship to Lower-Extremity Overuse Injuries

Lower extremity injuries appear to be a problem in the sport of football. An injury questionnaire study revealed that nearly 92% of college and university football players sustained a lower-extremity injury during a single football season and that 25% of these injuries were caused by repetitive-stress or overuse mechanisms. Since footwear has been implicated as one of the causes of lower-extremity overuse injuries, it was identified as an area that needed further investigation. It was theorized that stud placement on the sole of a football boot, with limited midfoot support, adversely affected the function of the foot which could lead to repetitive stress injuries. The effect of a modified loading condition, with the forefoot and heel elevated to the height of a moulded stud football boot, under static loading conditions showed no differences. It was determined that in order to obtain a truer picture of foot function, dynamic data needed to be collected. Navicular drop was selected as a criterion for measurement because the height of the arch is believed to be functionally significant for the mechanics of the foot. A dynamic method of measuring navicular drop during walking was developed utilizing a ProReflex® motion analysis system. Data were collected for the barefoot condition and while wearing turf trainers, football boots, and sports trainers. Statistical differences were found between static and dynamic barefoot navicular drop measurements. When using a large sample size, a corrolational relationship was found between the static and dynamic conditions leading to the conclusion that the foot may function similarly between static and dynamic loading conditions. However, further analysis of the timing of the movements showed that the maximum navicular drop occurred late in the stance phase and therefore static measurements might not reflect true foot function during dynamic activity. The timing curves obtained from the ProReflex® showed that shoes do seem to impair foot function, particularly during the recovery period. All of the shod conditions demonstrated a shorter recovery period, indicating that the foot may be unable to recover fully, and subsequently, may not become a fully rigid structure for propulsion. Maximum navicular drop values were also lower for the shod conditions, with the least amount of deformation occurring with the football boot. This might be caused by the rigid sole of the shoe not allowing the foot to unlock fully so that it can absorb impact forces and adapt to varying terrain. The effect of footwear on subtalar joint motion was also addressed using the ProReflex® system. No relationship was found between the amount of subtalar pronation or initial pronation velocity and navicular drop measurements in any of the conditions. However, motion curves showed that both structures were pronating to some extent, except the midfoot continued pronating while the rearfoot was beginning to supinate. The analysis of the motion curves of the navicular drop and subtalar joint indicate that the timing of foot motion is more important than the amount of linear or angular displacement. The relationship between displacement measurements may be negligible when determining the effect of the amount of pronation on the risk of injury. The timing variations seen within the subtalar joint and midfoot could lead to dysfunction of other structures, specifically the soft tissues, which would have to compensate for the altered movement patterns. A weakness or abnormality could lead to a breakdown, which in turn, could lead to injury

Volume 11, issue 3

The mission of CJS is to contribute to the effective continuing medical education of Canadian surgical specialists, using innovative techniques when feasible, and to provide surgeons with an effective vehicle for the dissemination of observations in the areas of clinical and basic science research. Visit the journal website at http://canjsurg.ca/ for more.https://ir.lib.uwo.ca/cjs/1090/thumbnail.jp

Form and function in the hominoid tarsal skeleton.

This thesis explores form variation in the adult tarsal skeleton of extant and fossil hominoids. Three dimensional coordinate data were obtained from five bones of the foot: the calcaneus, talus, cuboid, navicular and medial cuneiform. The comparative sample was made up of Homo sapiens, Pan troglodytes troglodytes, Pan paniscus, Gorilla gorilla gorilla and Pongo pygmaeus. The fossil sample consisted of tarsal remains assigned to a number of Late Pliocene taxa: Australopithecus afarensis, Australopithecus africanus, Paranthropus robustus and Homo habilis. Statistical shape analysis was conducted using geometric morphometric techniques. The first section of analysis explores sexual dimorphism in the extant hominoid foot. It is found that there is no shape dimorphism in the forefoot, and a marginal amount in the hindfoot of Gorilla and Pongo only. Such differences are likely to be linked to high degrees of body mass dimorphism in those taxa. The section concludes that shape dimorphism is unlikely to be an important factor in explaining differences between fossil hominin pedal remains. The second section explores the inter-specific relationship between the tarsals of the extant hominoids. It is found that shape differences between taxa closely mirror those differences already described in the literature. However, it is found that the phenetic relationship between the taxa varies from bone to bone, and, furthermore, does not match the consensus molecular phylogeny. The section concludes that some tarsals are more specialised and remodelled than others, and thus great caution should be taken when considering isolated fossil pedal specimens. The third section incorporates the fossil specimens into the study. It is found that the morphology of the A. africanus and H. habilis tarsals are very similar, and fall within extant hominoid intra-specific ranges of variation. However, the morphology of the A. afarensis tarsals are considerably distinct, and show a different overall pattern to those of A. africanus and H. habilis. The section concludes that all taxa were mosaic in their affinities, but were mosaic in different ways. This thesis concludes that it is likely that there were at least two distinct ways in which the tarsals of different hominin taxa had adapted to bipedal locomotion. This finding supports recent new discoveries suggesting a far wider degree of taxonomic diversity in the African fossil hominin record than had previously been thought

Effects of Knee Sleeves on Knee Mechanics During Squats at Variable Depths

The squat is a functional, compound and multi-joint exercise that targets several muscles of the lower body and is widely used in both athletics and many exercise programs. This exercise has been the subject of many studies, comparing different squat variations and examining how external gear, such as squat suits and knee wraps impact the exercise. The aim of this study was to assess the effects of wearing neoprene knee sleeves on lower extremity kinematics, kinetics, and muscle activations during weighted back squats. Fifteen resistance trained men and women, aged 28±5 years, from the local fitness community and university campus performed a one-repetition maximum (1-RM) of a deep squat during two separate sessions (5-7 days apart), one session while wearing knee sleeves and one session without; this was counterbalanced. A deep squat was classified as calf-hamstring contact in the bottom of the squat. Post 1-RM testing, two sets of three repetitions at a submaximal weight (80% 1-RM) were performed, one with deep squats (D) and one with parallel squats (P). A ten-camera motion capture system was used to collect three-dimensional (3D) kinematics and electromyography (EMG) was used to record muscle activity of the vastus medialis, rectus femoris, gluteus maximus, gluteus medius, and biceps femoris. Between sleeve and no-sleeve conditions, no significant differences were found in subject’s 1-RMs or in ratings of perceived exertion (RPE) during 1RMs or submaximal lifts. No significant differences were found in knee joint angles at maximum depth or in knee moments or powers during descent, maximum depth, or ascent. Only integrated gluteus maximus (GM) activation during ascent (full depth to standing) was significantly greater during no-sleeve (1.35±0.52 %MVIC*seconds) compared to the sleeve (0.98±0.48 %MVIC*seconds) condition (p=0.05; Cohen’s d = 0.74) during 1-RM testing. For submaximal sets, a significant main effect was found for external rotation moments during descent, where moments were larger for the sleeve compared to no-sleeve condition (p=0.05; d = 0.67). No other kinematic or kinetic differences were found between conditions. Similar to maximal sets, greater integrated GM activation was found without sleeves (0.53±0.19 % MVIC*seconds) compared to sleeves (0.44±0.13 % MVIC*seconds) (p=0.04; d = 0.55). No other differences were found in muscle activations during maximum or sub-maximum squats. Comparing the sub-maximal squat depths, peak knee flexion angles were significantly greater (

Initiation and control of gait from first principles: a mathematically animated model of the foot

The initiation of bipedal gait is a willed action that causes a body at rest to move. Newton's first principle of motion is applied to experimental footprint data. leading to the premise that the big toe is the source of the body action force that initiates and controls bipedal gait