Thesis (M.S.)--Northern Illinois University, 2008. / Adviser: Shin-Min Song. Includes bibliographical references.

published_or_final_version / Sports Science / Master / Master of Science in Sports Science

Thesis (M.S.)--University of Wisconsin--Madison, 1973. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf [35]).

Thesis (M. Sc.)--University of Hong Kong, 2005.

<p>Introduction: Dolomite AB was in need of a dummy arm for crutch testing, to complement their existing test capabilities. Background: A large number of people need crutches on a daily basis. For them it is essential that their crutches do not fail. ISO (the International Organization for Standardization) conducts ongoing work to guarantee the durability and function of e.g. crutches. ISO has recently adopted a new standard for testing if elbow crutches. This has already met resistance, it has been claimed that the tests in it should include loading of the crutch in the frontal plane. Aim: To enable Dolomite to test elbow crutches in accordance with guidelines in ISO/FDIS 11334-1. And examine the magnitude of loads on a crutch in the horizontal- sagittal- and frontal plane. This to see if loading of the crutch in the fontal plane should be included in a new ISO-test. Goal: To fabricate a dummy arm for testing of elbow crutches. To gain knowledge of the magnitude of the load a crutch is subject to in the horizontal-, sagittal-, and frontal plane. Method: A dummy arm was made using methods and tools described in DPD (dynamic product development), and conventional fabrication methods. A test equipment was made, which registered the loads on a crutch, in three directions. Eleven persons, constituted the test group, one was excluded. Result: A fully functional dummy arm was manufactured. The average maximum load for the ten test subjects was: 33 kilos downwards, 12 kilos backwards and 2 kilos side wards. Discussion: The choice of materials was influenced by the strength demands, ease of manipulation, access and price. Dummy arm design was mostly a question of durability and function. The test group was made up of persons available when the test was done The crutch loading test indicates that the forces applied to a crutch In the frontal plane are small, compared to forces in the horizontal- and sagittal plane, almost negligible. Conclusion: A fully functional dummy arm was fabricated, no need for a new ISO-test for standard crutches was identified.</p>

Introduction: Dolomite AB was in need of a dummy arm for crutch testing, to complement their existing test capabilities. Background: A large number of people need crutches on a daily basis. For them it is essential that their crutches do not fail. ISO (the International Organization for Standardization) conducts ongoing work to guarantee the durability and function of e.g. crutches. ISO has recently adopted a new standard for testing if elbow crutches. This has already met resistance, it has been claimed that the tests in it should include loading of the crutch in the frontal plane. Aim: To enable Dolomite to test elbow crutches in accordance with guidelines in ISO/FDIS 11334-1. And examine the magnitude of loads on a crutch in the horizontal- sagittal- and frontal plane. This to see if loading of the crutch in the fontal plane should be included in a new ISO-test. Goal: To fabricate a dummy arm for testing of elbow crutches. To gain knowledge of the magnitude of the load a crutch is subject to in the horizontal-, sagittal-, and frontal plane. Method: A dummy arm was made using methods and tools described in DPD (dynamic product development), and conventional fabrication methods. A test equipment was made, which registered the loads on a crutch, in three directions. Eleven persons, constituted the test group, one was excluded. Result: A fully functional dummy arm was manufactured. The average maximum load for the ten test subjects was: 33 kilos downwards, 12 kilos backwards and 2 kilos side wards. Discussion: The choice of materials was influenced by the strength demands, ease of manipulation, access and price. Dummy arm design was mostly a question of durability and function. The test group was made up of persons available when the test was done The crutch loading test indicates that the forces applied to a crutch In the frontal plane are small, compared to forces in the horizontal- and sagittal plane, almost negligible. Conclusion: A fully functional dummy arm was fabricated, no need for a new ISO-test for standard crutches was identified.

The proposed “natural crutch” provides ambulation assistance without the problems associated with arm-supported crutches. The new crutch has an exoskeleton structure which surrounds the disabled leg and carries the user's body weight while walking and standing. The load is transferred from the exoskeleton to the trunk of the body through a harness which lifts the pelvis on the impaired side. The intention is to simulate the internal skeleton’s natural load distribution while compensating for the impairment. The crutch design is presented as a unique concept with an outlined proposal for a marketable prototype. Results of a full scale simulator test are used to determine areas requiring further development. All aspects of design attempt to include both engineering and industrial design perspectives. / Master of Science

Millions of people each year spend some portion of their time using mobility aids to facilitate periods of non-weight bearing ambulation. The use of these devices changes the loading conditions of the lower extremities, which may result in skeletal muscle adaptations. The purpose of this work was to evaluate the effects of 3 types of mobility aids on lower-extremity muscle activity. Evaluation was based on 1) measured muscle activation signals using electromyography (EMG), and 2) measured joint kinematics and ground reaction forces, which were used to predict muscle forces. 16 healthy subjects (7 female, 9 male), ages 18-27 participated in the study. Subjects were instructed to ambulate using each of three mobility aids (crutches, a knee scooter and a temporary-injury prosthesis) as well as normal walking. EMG and motion capture were used to obtain bilateral data from the lower half of the body during ambulation on each of these mobility aids and walking (10 trials on each per subject). Muscles studied were right and left vastus lateralis (VLR, VLL), rectus femoris (RFR, RFL), Biceps femoris long head (BFR, BFL), and gastrocnemius medialis (GMR, GML). Joint kinematics and ground reaction force data (joint kinetics) were acquired using a standard camera-based motion capture system. The measured joint kinetics were used as inputs to the open source musculoskeletal biomechanics software OpenSim (SimTK, Stanford, CA), which allowed prediction of muscle force data for a representative subject during each mode of ambulation. As compared to walking, the following differences in EMG activation were significant. For the knee scooter, increases in VLR, RFR, BFL and decreases in GMR. For the TI prosthesis, increases in VLR, RFR, BFR, VLL, RFL, GML and decreases in GMR. For crutches, increases in BFR, VLL, RFL, BFL, GML and decreases in VLR, GMR. Muscle force results were similar, but demonstrated inadequacy of current musculoskeletal simulation software to resolve muscle forces during non-weight bearing portions of gait based solely on kinetic data. Results for walking data were similar to what is reported in the literature for normal gait. This study provides useful bilateral data that describe measured lower-extremity EMG activation amplitudes and muscle force predictions based on kinetic data during ambulation using three different ambulatory aids, compared to normal walking. Based on a criteria of maintaining muscle activation, the TI prosthesis proved most effective among the devices tested. The data presented will be valuable to clinicians in providing insight into which mobility aid may be best suited for a particular patient. It is anticipated that these data will provide designers of mobility aids with a protocol for evaluation of designs based on their potential to cause or prevent muscle adaptations.

BACKGROUND: In order to maintain non-weight bearing restrictions of the lower extremity, an assistive device must be utilized. Currently most devices require the restricted limb to be held in a static position while the contralateral extremity provides forward propulsion. Atrophy and disuse conditions ensue rapidly, slowing healing and prolonging recovery. A hands-free single crutch (HFSC) utilizes both lower extremities, potentially reducing atrophy. The purpose of this study was to examine the Electromyography (EMG) differences between a HFSC and standard axillary crutches (SAC). METHODS: A prospective, crossover study was performed using 21 healthy volunteers from an active duty foot and ankle clinic. Demographic data was obtained and then subjects were fitted with a HFSC and SAC. Wireless surface EMG sensors were applied to the belly of the rectus femoris (RF), vastus lateralis (VL), lateral gastrocnemius (LG), and the gluteus maximus (GM) by a board-certified orthopedic surgeon. Subjects then ambulated at a self-selected velocity for 30 meters, while 15 seconds of the gait cycle was recorded for each device. Mean muscle activity and the maximum voluntary isometric contraction (MVIC) were recorded. RESULTS: The RF, GM, and LG showed statistically significant increased levels of muscle activity while using the HFSC compared to SAC (respectively P = 0.05, P = 0.03, P = 0.03). The VL did not show statistically higher muscle activity while using the HFSC (P = 0.051). The RF, GM, and VL showed statistically significant higher MVIC percentages while using the HFSC compared to using SAC (respectively P = 0.005, P = 0.005, P = 0.013). The LG did not show statistically higher MVIC percentage while using the HFSC (P = 0.076). CONCLUSION: The HFSC subjects demonstrated increased muscle recruitment and intensity while maintaining cyclic contractions consistent with bipedal gait pattern. SAC demonstrated less recruitment and intensity with an isometric pattern regardless of the phase of gait. / 2022-06-04T00:00:00Z