Wilfrid Laurier University's Neuromechanics Laboratory supports research that investigates how footwear and foot disorders influence control of dynamic movements. The lab provides an opportunity for students to contribute to this emerging research area that could have a dramatic impact on our quality of life as we grow older.
The OR6 Series force platforms can be used for biomechanics, engineering, medical research, orthopaedics, rehabilitation evaluation, prosthetics and general industrial uses. Specific uses include gait analysis, stability analysis, neurological analysis, prosthetics fitting, athletic performance, shoe design, and force, power and work studies.
The AMTI OR6 Series force platforms were specifically designed for the precise measurement of ground reaction forces. The platforms measure the three orthogonal force components along the X, Y and Z axes, and the moments about the three axes, producing a total of six outputs. The high sensitivity, low crosstalk, excellent repeatability and long-term stability of these platforms make them ideal for research and clinical studies.
The pedar system is an accurate and reliable pressure distribution measuring system for the monitoring of local loading of the foot inside the shoe. The quality in-shoe dynamic pressure measuring system for gait analysis rehabilitation assessment shoe research and design, aid in shoe prescription and orthotic design field testing of sports applications kinetic analysis of free gait and long-term load monitoring.
Information from the skin of the foot sole has been shown to have a role in balance control. As we age the fidelity of the information relayed by the sensors in the skin is decreased. With a reduction in skin information, there are deficits in balance control and an increased incidence of falls in the elderly. Current strategies to improve balance involve the augmentation of skin input through vibration devices. Space flight provides a unique opportunity to further investigate the relationship between changes in balance control and skin contributions. During space flight, there are changes that occur with the postural control system due to the altered gravito-inertial environment. The specific changes that occur with skin have not been documented.
The proposal aims to use monofilament (vonFrey Hairs) and vibration testing to determine changes in skin sensitivity post space flight. Crew members will indicate when sensations are present during the testing paradigm. Post-Flight values will be compared to those obtained Pre-Flight. Values will also be correlated to changes observed in whole body postural control. It is hypothesized that skin sensitivity will be increased post space flight. This will be demonstrated by lower thresholds during monofilament and vibration testing. It is also hypothesized that increases in the sensitivity of the skin will correlate with balance deficiencies related to vestibular information. The results will formally document changes in skin sensitivity post-space flight and will contribute to our knowledge of current theories on skin contribution to postural control on earth.
Funded by the Canadian Space Agency.
The general objective of this research program is to investigate the mechanisms involved in realizing (neural activity) sensory information from the bottom of the feet and then how it is utilized in producing functional balance reactions during locomotion.
Previous research has focused on balance control during standing or stepping and has shown that sensation from the bottom of the feet plays an important role in dynamic balance control.
This program will examine the role of sensation from the bottom of the feet during level walking and perturbed walking, such as unexpected stopping or walking over uneven surfaces. The research environment permits the novel interaction between biomechanical assessment and recordings of neural and muscle activity. Measurement of muscle and neural activity, pressure and whole-body motion during these conditions will provide previously unexplored contributions of this sensation to dynamic balance control strategies and neural signal transmission.
Experimentally collected data will be used with an advanced mathematical model to gain further insight into the role of sensation from the bottom of the feet in producing dynamic balance reactions. This predictive modelling may be able to determine the potential risk of loss of balance of an individual with foot insensitivity. The long-term objectives include contributions to the understanding of the role of sensation from the bottom of the feet during dynamic situations and potentially to the design of environmental factors (e.g. footwear, flooring and insoles) that involve, either directly or indirectly, foot sole sensation.
Funded by the Natural Science and Engineering Research Council of Canada.
The purpose of this study will be to provide evidence that treatment of arthritis with high-dose fish oil supplements can improve strength and functional balance control, reduce medication requirements and improve quality of life over a 16-week period. Nearly four million Canadians are affected by arthritis. This is expected to escalate to six million in 20 years. The most dramatic aspects of arthritis include pain, activity restrictions and long-term disability. Most people affected by arthritis use non-steroidal, anti-inflammatory drugs (or other disease-modifying drugs) to reduce pain and thereby improve mobility. However, these drug therapies have been associated with gastrointestinal and cardiovascular side effects. An alternative to these drug treatments, high-dose fish oil supplements, has recently received elevated interest because of its effectiveness in reducing the body's inflammatory response.
We hypothesize that there will be significant improvements associated with increased levels of eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) in functional balance abilities and strength along with a reduction in pain and falls. These improvements will be evident in improved dynamic balance during locomotion, increases in production of joint torque, lower levels of reported joint pain, reduced number of falls reported and provide an improvement in overall quality of life. In addition to the functional capacity benefits of this type of intervention, it also has the potential to reduce or alleviate the dramatic side effects of the current drugs therapies used.
Funded by the Canadian Institutes of Health Science (Catalyst Grant: Pilot Projects in Aging).
One of the most pervasive effects of aging is a loss of cutaneous touch and pressure sensation. The loss of cutaneous sensation on the plantar surface (sole) of the feet has been correlated with impaired postural control (poor balance) and an increased risk of falling. In order to maintain a stable upright stance, the centre of gravity of the body must be positioned over the base of support established by the feet. Loss of balance and falling occur if the body weight is shifted too close to the limits of this base of support, too close to the perimeter of the plantar foot surface. A cutaneous sensation from the soles of the feet provides the central nervous system with this critical stability information. Numerous studies support the important contribution of cutaneous sensation from the plantar foot surface, in the control of postural balance. This cutaneous sensation acts, within the central nervous system, to trigger and/or modulate the automatic postural reflexes and reactions that act to prevent loss of balance.
Our research has shown that pressure sensation from the soles of the feet (plantar mechanoreceptors) plays an important role in controlling several key aspects of balancing reactions, particularly during compensatory stepping. As a result, age-related loss of plantar pressure sensation, which is very common, can lead to impaired control of these reactions. However, we have shown that it is possible to compensate for balance impairments resulting from this loss of sensation by using special footwear insoles to facilitate sensation from the perimeter of the sole.
To date, we have demonstrated the feasibility of this approach in laboratory studies and we have obtained a U.S. patent for the design concept. However, it remains to be determined whether the benefits of the footwear persist over the long term, or whether there is a habituation of the effect. Also, we need to determine whether there are any practical problems associated with wearing such footwear (e.g. discomfort or irritation of the skin).
Funded by a Candian Institutes of Health Research "Proof of Principle" Award.
Falls are a serious healthcare problem among older adults. Foot problems are one of the factors that can increase the risk of falling. My research program is targeted at understanding how foot problems affect an individual's balance. In order to isolate the underlying factors that may impair balance, I have identified three specific areas that most foot problems can be categorized into sensation from the bottom of the foot, foot mechanics and foot pain. Problems that exhibit characteristics in any of these areas can potentially affect how an individual is able to detect that they are out of balance and can also affect how successfully they can produce a balance reaction in response to becoming unstable.
The focus of this pilot project is to build and test an experimental setup to simulate gait over uneven terrain. Initially, slightly inclined platforms will be constructed and placed at each foot contact position, during walking, to simulate variations in surface orientation (e.g. uneven sidewalks). Then a population of healthy young adult individuals will be tested to determine the effect of the uneven terrain on their balance control during gait.
This experimental setup will be a critical component of future work in the evaluation of the postural control system to prevent falls in older adults.
Funded by a Wilfrid Laurier University Post-Doctoral Fellowship Award.
The purpose of this study was to determine the influence of different midsole hardnesses on dynamic balance control during unexpected gait termination.
Twelve healthy young female adults were asked to walk along an eight-metre walkway, looking straight ahead. During 25% of the trials, they were signalled (via an audio buzzer) to terminate gait within the next two steps. The four experimental conditions were:
Center of mass (COM) position relative to the lateral base of support (BOS), center of mass – center of pressure (COM-COP) difference and vertical loading rate were used to evaluate the influence of midsole material on dynamic balance control. The results were a decrease in the medial-lateral range of COM with respect to the lateral BOS, a reduction in the maximum COM-COP difference and an increase in the vertical loading rate due to the presence and hardness level of the midsole material when compared to the barefoot condition.
The primary outcomes of this study have illustrated the influence of midsole hardness as an impediment to dynamic balance control during responses to gait termination. In conclusion, the present study suggests that variations in midsole material, and even the presence of it, impairs the dynamic balance control system.
Funded by a Wilfrid Laurier University Undergraduate Research Assistantship.
This study examined the effects of hormone replacement combined with strength training on improving dynamic balance control in post-menopausal women.
Thirty-one participating post-menopausal women were divided into three groups; hormone replacement (HR), non-hormone replacement (NR) and control (CR) group. HR and NR groups were tested for muscle strength and balance control during gait, prior to training and following a six week lower body strength training program. Quadriceps muscle strength was evaluated as isokinetic peak torque (60 /sec) using a CYBEX NORM and balance control was evaluated by center of mass – base of support relationships and ground reaction forces during gait perturbations.
Only the HR group showed significantly (p < 0.05) improved balance control during the initial phase of unexpected gait termination and single stance periods while walking across uneven terrain following training. The strength gains in the HR group tended to be greater than in the NR group over the six-week training program, although neither group showed statistically significant increases. The CR group showed no significant differences between testing times. HR in post-menopausal females may enhance dynamic balance control when combined with a strength training program, even if no statistically significant gains in strength are achieved.
Funded by a Candian Institutes of Health Research "Development Fund" Award for Wilfrid Laurier University.
This study was undertaken to determine if an Artificial Neural Network based model could be used to approximate an individual’s center of mass (COM) during dynamic movements in upright stance given only pressure data originating from pressure sensing insoles. This type of modelling may provide insight into how the human postural control system uses this sensory information to control balance.
The activity was voluntary leaning in four directions (forward, right, left and backwards) all held for just over a second. The model demonstrated good prediction of the COM in the anterior/posterior direction such that the predicted COM approximation was within 10 mm of the measured COM. Extension of this model to 2-D space, incorporating medial/lateral information, has also given a good prediction of the COM location.
Pilot work has also begun on modelling the COM and its relationship to the base of support during gait using pressure insoles; some data is presented here and has shown encouraging results as we continue to the next logical stage of development.
Funded by SHARCNet Undergraduate Fellowships.
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