«A Thesis Submitted to the Graduate Faculty of the Louisiana State University and Agricultural Mechanical College in partial fulfillment of the ...»
BIOMECHANICAL EVALUATION OF MODIFIED TRACK SHOES
Submitted to the Graduate Faculty of the
Louisiana State University and
Agricultural Mechanical College
in partial fulfillment of the
requirements for the Degree of
Master of Science in Industrial Engineering
The Department of Construction Management and Industrial Engineering
Marlon Alberetos Greensword
B.S., L.S.U., 2007
B.A., L.S.U., 2005
ACKNOWLEDGMENTSI must first give thanks to God the Father, Jesus the Son and the Holy Spirit for their guidance, wisdom, and understanding through my journey in graduate school and in my life.
I would like to thank my advisor and thesis director, Dr. Fereydoun Aghazadeh, for his continuous guidance, encouragement, and support throughout my graduate school experience. I insist on expressing my sincere appreciation as he has been one of my most influential advisors, guides, or mentors. I would also like to thank committee members Dr. Ikuma and Dr. Nahmens, who helped me perform to the best of my ability. Your insight, patience, and recommendations are greatly appreciated.
I wish to bestow my deep gratitude to my father Anthony Greensword and mother Joan Bowen. I also want to express special thanks to my brother Mark Greensword and my Uncle Simon Bowen for their support.
Dr. Ashish Nimbarte, I am grateful for your advice and guidance during my research.
I am as well indebted to all my subject volunteers for their time and the physical participation in the lengthy series of experiments.
Coach Mark Elliott, thank you for helping me identify the needs of a track athlete. I would not be where I am if it were not for your continuous encouragement and guidance in my personal, scholarly, and athletic experience. I would also like to show appreciation to my friend Mario Kelly and sister-in-law Angelique Ngandu for their support.
Finally, I dedicate this thesis to my wife Sylviane Kalenga Greensword; without her love and support, this project would not have been a reality.
TABLE OF CONTENTS
LIST OF TABLES
LIST OF FIGURES
1. INTRODUCTION AND BACKGROUND
2. LITERARY REVIEW
2.1. Common Running Injuries
2.2. Running and Walking Techniques and the Common Track Spike Shoe
2.2.1. Running and Walking Biomechanics
2.2.2. Muscles Involved: The Extrinsic Foot Muscles
184.108.40.206. The Tibialis Anterior Muscle
220.127.116.11. The Gastrocnemius Muscle
2.3. Transition between Running and Walking
2.4. Consequences of Inappropriate Equipment
2.5. Electromyography (EMG)
2.5.1. Definition and Explanation
2.5.2. EMG Applications in Biomechanics, Work Physiology, and Kinesiology.......... 21
2.6. Previous Use of Removable Heels
Ladies‟ High Heel Shoes with Removable Heels
5. METHODOLOGY AND PROCEDURES
5.2. Equipment / Apparatus
5.3. Task Design
5.3.1. Installation of the Heel
5.3.2. EMG Experiment
5.3.3. Body Maps
5.4. Nature of the Data
5.5. Hypothesis: Statement and Parameters
5.5.1. Hypothesis Testing
iii 5.5.2. Statistical Analysis
5.5.3. Steps for Data Processing
6.1.1. Muscles Evaluated
6.1.2. Impact of Speed on Muscle Activity
Impact of the Participant‟s Running Background
6.1.4. Statistical Results
18.104.22.168. Hypothesis 1
22.214.171.124. Hypothesis 2
6.2. Body Maps
6.2.1. Statistical Results: Hypothesis 3
Relevance of the Participants‟ Athletic Background
6.2.3. Remaining Discomfort
7.1.1. Limited Number of Participants
7.1.2. Limited Prototype Quantity
7.2. Further Developments
7.2.1. Running and Monitoring Conditions
7.2.2. Participants Selection and Shoe Characteristics
7.2.3. Further Assessment
7.3. Final Remarks
APPENDIX A: CHANGES IN MUSCLE ACTIVITY
APPENDIX B: BODY MAPS
Table 5.1: Participant running profile
Table 6.1: Average EMG values
Table 6.2: Percent average of muscle activity decrease from walking without heels to walking with heels
Table 6.3: Analysis of variance for gastrocnemius and tibialis anterior activity
Table 6.4: Averaged discomfort values before and after heel installation
Table 6.5: ANOVA formulas by area
Table 6.6: ANOVA of body map results
Table A.0.1: Detailed fatigue change for each subject from EMG results
Table B.0.1: Discomfort values before and after heel installation
Table B.0.2: Histogram of EMG Results of Tibialis Anterior Activity for Each Participant....... 76 Table B.0.3: SAS results for discomfort before and after heel installation
Figure 1.1: Example of a typical track spike shoe used by runners
Figure 2.1: Common overuse running injuries of the lower limbs
Figure 2.2: Biomechanics of a normal human ankle during level-ground walking
Figure 2.3: Ankle torque versus angle during level-ground walking
Figure 2.4: Pendulum apparatus used to test impact forces
Figure 2.5: Anterior and lateral views of extrinsic foot muscles
Figure 2.6: and muscle activity during normal walking gait cycle
Figure 2.7: Electromyogram - Example 1
Figure 2.8: Bowling Shoe with Famolare's Separate Heel and Sole Pad
Figure 2.9: Bowling Shoe with Attached Sole Pad and Heel
Figure 2.10: View of Lombardino's Shoe Sole with Original Heel Removed
Figure 2.11: Profile View of Lombardino's Shoe with No Heel Attachment
Figure 2.12: View of Lombardino's Shoe with New Heel Attachment
Figure 2.13: Shoe construction with self-seating removable heel
Figure 2.14: Shoe construction with self-seating removable heel_2
Figure 2.15: Side view of shoe with high heel and low heel
Figure 2.16: The high heel removal process
Figure 2.17: Side and top views of the adjustable shank
Figure 2.18: View of shoe with low and high heel when adjusted with the adjustable shank.
.... 31 Figure 5.1: Spike shoe with removable heel - side view
Figure 5.2: Spike shoes: heel v.
no heel - rear view
Figure 5.3: Myomonitor Main Unit
Figure 5.4: DE-2.
3 Single Differential Surface EMG Sensor
Figure 5.6: Input Module
Figure 5.7: EMG alignment
Figure 5.8: Subject performing during treadmill experiment
Figure 5.9: EMG Sensor orientation with respect to the muscle fibers
Figure 5.10: Body map sections
Figure 5.11: Borg's scale for fatigue measurement
Figure 6.1: EMG results at 2 mph
Figure 6.2: EMG results at 3 mph
Figure 6.3: Effect of heels on EMG for different speeds
Figure 6.4: Percent decrease in EMG when the heel is added
Figure 6.5: Percent decrease in tibialis activity for each participant group
Figure 6.6: Plot diagram comparing decrease in tibialis activity for each group according to speed
Figure 6.7: Percent decrease in gastrocnemius activity for each participant group
Figure 6.8: Diagram comparing decrease in gastrocnemius activity for each group according to speed
Figure 6.9: Average discomfort when walking without heels and walking with heels.
............... 60 Figure 6.10: Graphed ANOVA results by area
Figure 6.11: Average discomfort difference by participant athletic category
Figure A.1: Histogram of EMG Results of Gastrocnemius Activity for Each Participant........... 73 Figure A.2: Histogram of EMG Results of Tibialis Anterior Activity for Each Participant........ 73 Figure B.1: Graph of Body Map Reports for Each Participant
Track and field runners, especially sprinters and mid-distance runners, face many problems due to walking in spike shoes. Due to the fact that track and field spike shoes are designed specifically for running, the runner‟s feet remain in an uncomfortable, flexed position when walking between workouts and races. Problems caused by the dangerous foot-positioning include, but are not limited to, the following: back pain, shin splints, bone spurs, blisters, and overall decreased level of running performance. Over time, runners wearing improper footwear for walking may face chronic injuries such as plantar fasciitis, shin splints, Achilles tendinitis, chondromalacia, and iliotibial band syndrome. To address this problem, a modified spike shoe was tested. The modification consists of adding a removable heel to the shoe. The removable heels were attached to the sole after exercise or between races to shoe angle of flexion, so that the foot can be leveled. The modified shoes were tested in terms of health and comfort through the use of two experimental protocols. Nine healthy, resistance-trained participants volunteered to perform walking drills on a treadmill. They walked with regular spikes at 2 mph and 3 mph.
Then, they repeated the drill with the redesigned spike shoes. EMG measurements were used to evaluate the participant‟s muscle activity, fatigue, and stress during the exercise. The analyzed muscles were the tibialis anterior and the medial gastrocnemius. The statistical tool used for the mathematical interpretation of the data was ANOVA, the hypotheses being tested with the softwares Statistix 9.0. and SAS 9.1 English version. Complementarily, participants were individually asked to rate their discomfort on a scale of 1 to 10, using a body map as a further evaluation of the effects of the removable heel. Results showed a 22 % average decrease in EMG muscle activity from walking without heels to walking with heels in the tibialis anterior and a
map survey results indicate that participants noticed an average superior comfort of 2.7 points in the knees, 2.6 points in the calves, 3.9 points in the ankles, and 4.2 points in the feet on an ergonomic scale of 10 discomfort points. Thus, results showed that the removable heel helps reduce muscle fatigue and stress and therefore its related musculoskeletal problems.
Track-and-field athletes wear spike shoes, which are designed exclusively for running during training and competition (track meets). Based on observations of the LSU track team during regular track season, athletes wore their spike shoes for a daily average of one hour and 25 minutes, of which 45 minutes are spent walking. In addition, further observations indicated that, between workouts, athletes walk in their spikes on an average of 5 hours per week, which indicated an excessive time spent in footwear not meant for walking. Over a span of time, depending on the spike shoe design, some sprinters and mid-distance athletes (800 m runners) suffered several injuries, especially while walking in their spike shoes, which are made only for running. Such injuries include plantar fasciitis, shin splints, Achilles tendinitis, chondromalacia, and iliotibial band syndrome (McGrath and Finch, 1996).
Spike shoes' shapes differ depending on the athlete‟s area of competition (mid-distance, sprint/short distance (50 to 400 m), long distance (1 mile to marathon), jumps, etc.). These lightweight shoes are named after the small metal spikes that range in size, depending on the track surface on which an athlete competes. The metallic pieces are attached to the bottom of the shoes. Thus, they are removable, and the athlete may replace them with longer or shorter spikes according to his or her needs. Spikes also differ in aerodynamics, depending on the event.
Runners use this specific type of shoe, because the shoe enables their feet to stick to the mondo or rubber surface, thereby minimizing shock and sliding.
This project is designed to test the feasibility of an innovative track-and-field spike shoe.
In the first approach, a description of the ideal shoe that track-and-field athletes need provides data such as shape and materials needed.
Figure 1.1: Example of a typical track spike shoe used by runners The second part exposes the main problems currently encountered with some of the classic spikes.
This section is introduced with pictures showing different dimensions of the spike and is followed by an analysis of the shoe‟s potential harm to the athlete‟s feet. In effect, the shoes were created to fit runners, and therefore, wearing them for a different activity – in this instance, walking – may cause back pain, shin splits, bones pure, and blisters. It also tends to decrease running performance, since injured runners cannot perform to the best of their abilities.
Thirdly, the solution proposed and tested in this project is a shoe with a removable heel, that is, the opportunity for every track-and field athlete to get their own custom-built spikes specified to his or her activity – running and walking. The efficiency of this feature is tested on the classic Nike spikes, in terms of health protection and athletic performance, focusing on muscle fatigue.
Finally, this thesis concludes by elaborating on the implication of the study, including notes for further research.
Regarding the commerciality of the product, one must note that some of the features hereby proposed have already been presented but have never been applied to spike shoes. If Nike were to adopt such a proposition, they would gain a wider clientele on the track-and-field market, more satisfied customers, as well as promotional benefits in terms of their interest in preserving the athlete‟s health.