Jack R. Engsberg

Range of Motion of the Foot as a Function of Age

Movement of the foot is essential for human locomotion. The purpose of this paper was to quantify the range of motion of the foot as a function of age and to compare the rage of motion measurements for the foot in a laboratory coordinate system and a coordinate system fixed to the tibia. The measurements were taken in vivo using a range of motion instrument developed by Allinger (University of Calgary, Canada, 1990) from 121 subjects. The results suggest that: (1) the range of motion in general is greater for women than for men in the young adult group; (2) the range of motion in general is in the same order of magnitude for women and men in the oldest age group; and (3) the range of motion is about 8° smaller in dorsiflexion and about 8° higher in plantarflexion for women than for men in the oldest age group. It is speculated that physical activity and common shoe wear are factors influencing the age- and gender-dependent differences in range of motion. Furthermore, it has been shown that the range of motion values measured in a laboratory coordinate system and in a coordinate system fixed in the tibia are different in all directions except inversion. The differences in plantarflexion and dorsiflexion and inversion and eversion are relatively small. However, they are substantial for adduction and abduction. In all cases, the results were bigger for measurements in the laboratory coordinate system compared with the tibia coordinate system, because the movement of the lower leg was included in the measurements in the laboratory coordinate system. The data indicate that foot range of motion is different for women and men. Consequently, it is speculated that these differences may be related to possible overloading of the locomotor system, especially in sporting activities in which the loading of the foot is significant. The differences in the plantarflexion and dorsiflexion direction were assumed to influence the loading of the Achilles tendon, and it is suggested that some of the Achilles tendon problems may be predictable based on range of motion measurements.

Differences in Ankle Joint Complex Range of Motion as a Function of Age

The purpose of this study was to determine whether gender- and age-related differences in ankle joint complex (AJC) range of motion (ROM) exist in children (range 9–13 years), adolescents (14–16 years), and young adults (17–20 years), and to compare these data with those published for older subjects (21–79 years) using the same protocol. 15 A total of 120 subjects (58 males and 62 females) ranging in age from 9 to 20 years were tested for AJC ROM using a specifically designed 6° of freedom fixture. 1 All measurements were made with respect to a laboratory coordinate system, and represented assessment of active AJC ROM. Angular displacements for plan-tarflexion, dorsiflexion, inversion, eversion, abduction, and adduction were digitally recorded and compared. AJC ROMs of females aged 9 to 20 years were generally greater than those for males about all three orthogonal axes. Within each gender, there was a consistent trend for AJC ROM to decrease from a maximum at 14 to 16 or 17 to 20 years to a minimum after age 60 years. The average decrement was greater for females than for males. This study provided evidence to support the contention that age-related and gender differences in AJC ROM do exist. The possibility of minimizing the decline in AJC ROM with age requires further investigation.

A METHOD TO DETERMINE THE RANGE OF MOTION OF THE ANKLE JOINT COMPLEX, IN VIVO

The purpose of this investigation was to develop a method to quantify a range of motion of the ankle joint complex (AJC) in vivo. A six-degree-of-freedom apparatus was constructed to measure the unconstrained active range of motion of the AJC. Extensive tests evaluating the accuracy of the fixture and data collection protocol were conducted. Euler angles similar to dorsiflexion-plantarflexion, eversion-inversion, and abduction-adduction were used to quantify the range of motion. Significantly greater (p < 0.05) values were found for plantarflexion, inversion, and abduction of a young group of male subjects (n = 7) compared to an elderly group of male subjects (n = 10). In addition, maximum range of motion values did not necessarily occur from the neutral position. In future, this method can be used to help investigate the relationships between AJC motion and injury, changes in range of motion as a function of age, and design of prosthetic ankle joints.

A CAD CAM method for custom below-knee sockets.

The purpose of this investigation was to develop a numerical method for fabricating prosthetic sockets for below-knee amputees. An opticalllaser digitiser scans an amputees stump and collects three dimensional numerical data describing the surface of the limb and describing specific modification site locations. The numerical data from the laser camera representing the stump and modification sites are altered by the prosthetist using a custom computer aided design software system running on a personal computer. Using the altered numerical data a programme is created for a high resolution numerically controlled milling machine and a mould is made. The prosthetist then fabricates a socket. While the system has been tested with below-knee amputees it has been designed for application in most areas of prosthetics and orthotics. Utilising this method 15 patients were fitted. All patients sujectively stated that their “computer designed” socket fitted better than their conventionally made socket. As the research progressed and experience was gained with the system patients were normally fitted with the first socket iteration. The system overcomes five limitations existing with some of the other numerical systems: 1) accurate high resolution surface topography, 2) specific identification of subject modification sites, 3) flexible, user friendly software, 4) high resolution numerically controlled milling, and 5) integrated expansion to other prosthetic and orthotic areas.

Weight distribution of below-knee amputee and able-bodied children during standing

The purpose of this investigation was to compare weight distributions of a relatively large number of below-knee (BK) amputee and able-bodied children during two different standing positions. Twenty-one BK amputees and 200 able-bodied children volunteered as subjects for this investigation. Each child stood on a pressure plate and three sets of trial data were collected. One set of trial data was collected with both feet together on the pressure plate and two were collected with feet placed 20cm apart. The total force applied by each foot to the pressure plate was normalised by dividing by subject weight to yield foot force to body weight ratios. Data were separated into forefoot and rearfoot areas, force for the forefoot area was then calculated and normalised by dividing by total foot force to yield forefoot to whole-foot force ratios. Ratios for the two foot placement conditions and for non-prosthetic, prosthetic, dominant, and non- dominant feet were compared using paired t- tests (p < 0.05). Results indicated that: 1) BK amputee children placed more weight on their non-prosthetic limb than their prosthetic limb, yet this was not different from able-bodied children in respect of weight distribution between dominant and non-dominant limbs; 2) approximately 90% of the load on the prosthetic foot was placed on the forefoot; and 3) the load on the non-prosthetic foot was evenly distributed between the forefoot and rearfoot like that of able-bodied children. It was concluded that except for substantially more weight on the forefoot of the prosthetic leg BK amputee children stood in the same way as able-bodied children.

Standing pressure distribution for normal and below-knee amputee children

Below-knee (BK) amputee children have a different morphology from normal children and amputees may thus have atypical limb loading during standing. The purpose of this investigation was to examine differences in standing ground-shoe pressure distribution between BK and normal children. A pressure plate was used to measure the ground-shoe weight distribution of three BK children and ten normal children during standing. Results indicated that the weight distribution between prosthetic and non-prosthetic limbs of BK children was not significantly different from the feet of normal children. The anterior-posterior weight distribution for the prosthetic and non-prosthetic feet was significantly different from that of the normal children. Further quantification of weight distribution and analysis of more subjects is necessary to determine the benefits, detriments, or irrelevance of these results.

A Function of the Talocalcaneal Joint during Running Support

This study explored the possible function of the talocalcaneal joint during running support to minimize frontal plane rotation of the leg and thereby protect the knee from excessive frontal plane motions. The lower limb was modeled as two rigid segments representing the foot and the leg. The results indicated that for extreme ground-foot angles the talocalaneal joint was able to maintain the knee in a stable position in the frontal plane. It was concluded that the joint may function to minimize frontal plane rotation of the leg and thereby protect the knee from excessive frontal plane motions. The relevance of this function for a below-the-knee-amputee patient lies in the potential for improved prosthetic design.

Reliability and validity of the Microsoft Kinect for assessment of manual wheelchair propulsion

Concurrent validity and test-retest reliability of the Microsoft Kinect in quantification of manual wheelchair propulsion were examined. Data were collected from five manual wheelchair users on a roller system. Three Kinect sensors were used to assess test-retest reliability with a still pose. Three systems were used to assess concurrent validity of the Kinect to measure propulsion kinematics (joint angles, push loop characteristics): Kinect, Motion Analysis, and Dartfish ProSuite (Dartfish joint angles were limited to shoulder and elbow flexion). Intraclass correlation coefficients revealed good reliability (0.87-0.99) between five of the six joint angles (neck flexion, shoulder flexion, shoulder abduction, elbow flexion, wrist flexion). ICCs suggested good concurrent validity for elbow flexion between the Kinect and Dartfish and between the Kinect and Motion Analysis. Good concurrent validity was revealed for maximum height, hand-axle relationship, and maximum area (0.92-0.95) between the Kinect and Dartfish and maximum height and hand-axle relationship (0.89-0.96) between the Kinect and Motion Analysis. Analysis of variance revealed significant differences (p < 0.05) in maximum length between Dartfish (mean 58.76 cm) and the Kinect (40.16 cm). Results pose promising research and clinical implications for propulsion assessment and overuse injury prevention with the application of current findings to future technology.

A new combined motor and cognitive strategy training intervention for stroke: Stakeholder perceptions:

Introduction Hemiparesis affects about half of persons with chronic stroke and frequently leads to decreased participation in meaningful daily life activities. The purpose of this investigation was to evaluate the perceived acceptability and practicality feasibility of a complex intervention for addressing motor impairment and activity limitations post stroke. The newly developed intervention, Metacognitive Virtual Reality (MetacogVR), combines virtual reality technology to improve motor impairments with task-based, cognitive strategy training for meaningful transfer of skills. Method Three separate focus groups were held with stakeholders including persons with stroke (nu2009=u20095), caregivers (nu2009=u20095), and occupational therapists (nu2009=u20095). Focus groups were audio recorded and transcribed. Data were analyzed using inductive content analysis. Results Themes revealed stakeholder perceptions of the intervention as a cost-efficient and transportable intervention. The time commitment of the intervention was acknowledged as intense, but necessary for optimal improvements. Findings also included perceptions of the intervention as highly motivating and client-centered. Essential elements of guided discovery, cognitive strategies, and high repetitions were seen as facilitators of the intervention. Conclusion Results indicate MetacogVR has positively perceived acceptability and practicality feasibility. Findings warrant further feasibility testing of MetacogVR prior to efficacy testing.

Changes in gait kinematics for a recent below the knee amputee child

The purpose of this preliminary study was to make kinematic comparisons of a recent below-the-knee amputees (BKA) gait with the gait of normals and an experienced BKA. Kinematic data were collected for four normal children, an experienced BKA child, and a novice BKA child. The results indicated that over time, the novice BKA seemed to approach a pattern more similar to that of the experienced BKA than that of the normal children. The differences in gait could be an appropriate adaptation to the morphological and physiological needs of the BKA subjects, suggesting that attempts to modify the gait of these subjects toward normal patterns might not be in their best interest.<<ETX>>