Darla Smith - Academia.edu (original) (raw)

Papers by Darla Smith

International Journal of Exercise Science, 2012

The objective of this review was to analyze the current literature related to the effects of obes... more The objective of this review was to analyze the current literature related to the effects of obesity on balance. These effects were observed during conditions of static balance, perturbed balance and dynamic balance during gait. The literature review included studies focused on the biomechanical effects of obesity, the relationship between weight loss and balance, and the relative efficacy of weight loss as a balance intervention. The older adult population, which faces increased risk of falls and related injuries, was highlighted where targeted research was available. The existing literature provides evidence for a strong link between obesity and balance impairments. This meta-analysis supports the efficacy of weight loss as an intervention to improve balance in the obese. Additional investigations are needed to confirm the reliability of relationships noted in this review paper, and to explore the potential of weight loss in simple and combined interventions. Future research should also determine whether efficacy differs among populations.

Research Quarterly For Exercise and Sport, Mar 1, 2003

Female athletes are at least twice as likely to sustain an anterior cruciate ligament injury than... more Female athletes are at least twice as likely to sustain an anterior cruciate ligament injury than male athletes. The underlying cause of ACL injury is multifactorial. However, several researchers have identified knee joint laxity as a possible contributing factor. The purpose of this study was to provide a comparison of knee joint laxity between male and female collegiate soccer players and male and female non-athletes. Thirty-nine (19 male, 20 female) apparently healthy, collegiate athletes from the University of Texas at El Paso's 2001-2002 women's intercollegiate soccer team and men's club soccer team, and forty (20 male, 20 female) non-athletic students volunteered to participate. All participants were tested bilaterally using the KT-1000 MEDmetric knee joint ligament arthrometer. Three tests were used to determine anterior laxity: passive displacement, active displacement, and the Lachman test. The mean passive displacement, mean active displacement, and Lachman (only for the left leg) were significantly lower for the athletic group than for the non-athletic group. There were no significant differences found between males and females for the passive and active drawer tests. However, females had significantly more laxity than males in the Lachman test. These findings suggest that strength and conditioning may play a more significant role in knee joint laxity than the sex of the individual.

International Journal of Exercise Science Conference Proceedings, 2010

International Journal of Exercise Science Conference Proceedings, 2010

Http Dx Doi Org 10 1080 08924562 2011 10590926, Jan 16, 2013

Isbs Conference Proceedings Archive, Nov 1, 2007

Isbs Conference Proceedings Archive, Oct 28, 2007

The purpose of the study was to compare the cushioning effect of the Nike Air Pegasus 2004 and th... more The purpose of the study was to compare the cushioning effect of the Nike Air Pegasus 2004 and the Spira Volare IITM during running. Measured variables were peak force, peak force relative to body weight and time-to-peak force. It was determined that time-to- peak force was not significantly different (p=0.1745) between the Spira and the Nike. There were significant differences

2007 IEEE 10th International Conference on Rehabilitation Robotics, 2007

Abstract-This paper discusses the design and implementation of a fuzzy inference system for the r... more Abstract-This paper discusses the design and implementation of a fuzzy inference system for the recognition of human gait phases. In particular, this work focuses on using the angles of the joints of lower limb to determine the current stage of a subject's gait cycle. The fuzzy rule-...

Strength and Conditioning Journal, 2007

Research Quarterly for Exercise and Sport, 2012

In this study, we compared hamstring (H) and quadriceps (Q) strength changes in men and women, as... more In this study, we compared hamstring (H) and quadriceps (Q) strength changes in men and women, as well as changes in conventional and functional H:Q ratios following an identical 12-week resistance training program. An isokinetic dynamometer was used to assess 14 male and 14 female participants before and after the intervention, and conventional and functional H:Q ratios were calculated. Hamstring strength improved similarly in men and women, but improvement in quadriceps strength was significantly greater in men, while women showed only modest improvements. For the conventional and functional H:Q ratios, women showed significantly greater improvements than men. Both men and women were able to exceed the commonly recommended 0.6 conventional and 1.0 functional H:Q ratios after the 12-week lower-body resistance training program.

Perceptual and Motor Skills, 2001

The purpose of this study was to provide quantitative data about changes in coordination after pr... more The purpose of this study was to provide quantitative data about changes in coordination after practicing a racquetball forehand drive serve. Novice women (N = 10) were videotaped before and after 10 min. of practicing a racquetball forehand drive serve on Day 1, and after 10-min. practice sessions on consecutive Days 2 through 5. The PEAK5 Motion Measurement System was used to evaluate the following dependent variables: (a) range of motion of the wrist, elbow, upper torso, and pelvis from backswing to ball contact: (b) racket head velocity at ball contact; and (c) coordination. Coordination was evaluated based on analysis of the angular velocity graphs of each performance to assess sequencing and timing of the segmental contributions. Shared positive contribution was assessed between adjacent 2-segment combinations: pelvis-torso and elbow-wrist. A repeated-measures analysis of variance indicated racket velocity, pelvic rotation, and upper torso rotation significantly increased over the 5 days of practice. Although participants increased their pelvic and torso ranges of motion and racket velocity, improvement in coordination was not documented.

The purpose of this study was to compare the cushioning effect of three top rated running shoes a... more The purpose of this study was to compare the cushioning effect of three top rated running shoes and a new spring shoe technology. Shoes were mechanically dropped onto an AMTI force platform. The average in peak forces and the time to peak force were calculated to compare cushioning effect over multiple trials. The Nike and the Spira were found to be significantly better in both cushioning variables than the Adidas and Asics, but not significantly different from each other.

Medicine & Science in Sports & Exercise, 2007

Journal of Physical Education, Recreation & Dance, 2004

Human Movement Science, 2011

This study compared the biomechanical adaptation to running shoe degradation between the dominant... more This study compared the biomechanical adaptation to running shoe degradation between the dominant (D) and non-dominant (ND) leg. Twenty-four runners performed a pre-test in the laboratory, completed 200 miles of road running in a pair of assigned shoes and then returned for a post-test. Kinetic and kinematic data of running in new and worn shoes were collected. Repeated measures ANOVA (Shoe  Leg) were used to analyze temporal, kinetic and kinematic variables (a = .05). A symmetry index (SI) was calculated for the temporal and kinetic variables and paired t-tests were used to compare the SI between shoe conditions. Stance time increased by approximately 7 ms in worn shoes (p = .027). Bilateral differences in the kinematic change (Shoe  Leg interaction) were seen in the torso (p < .05), knee (p < .05), marginally at the hip (p < .10) but not the ankle. No difference in kinetic variables or SI was observed. When running in worn shoes, the torso displayed reduced forward lean for both sides and to a greater extent during the D leg strike. The D hip and knee showed a more extended position for the worn shoe condition while an increased flexion was observed in the ND leg. Most of the kinematic differences observed were small and within the intra-subject variability measured during the same session. Future studies may consider performing a three-dimensional analysis at a higher sample rate and further explore whether asymmetrical adaptation is related to running injuries.

British Journal of Sports Medicine, 2009

In this study, the effect of shoe degradation on running biomechanics by comparing the kinetics a... more In this study, the effect of shoe degradation on running biomechanics by comparing the kinetics and kinematics of running in new and worn shoes was investigated. Three types of footwear using different cushioning technologies were compared. Design: Longitudinal study. Setting: Pre-and post-tests on overground running at 4.5 m s 21 on a 20-m laboratory runway; performance measured using a force platform and a motion capture system. Participants: 24 runners (14 men and 10 women) Interventions: 200 miles of road running in the same pair of shoes. Within-group factor: shoe condition (new/ worn); between-group factor: footwear type (air/gel/ spring). Main outcome measurements: Stance time was calculated from force data. External loads were measured by maximum vertical force and loading rate. Kinematic changes were indicated by sagittal plane angles of the torso, hip, knee and ankle at critical events during the stance phase. Results: Stance time increased (p = 0.035) in worn shoes. The torso displayed less maximum forward lean (p,0.001) and less forward lean at toe-off (p,0.001), while the ankle displayed reduced maximum dorsiflexion (p = 0.013) and increased plantar flexion at toe-off (p,0.001) in worn shoes. No changes in the hip and knee angles. No between-group difference among the three footwear groups or condition by type interaction was found in any measured variables. Conclusions: As shoe cushioning capability decreases, runners modify their patterns to maintain constant external loads. The adaptation strategies to shoe degradation were unaffected by different cushioning technologies, suggesting runners should choose shoes for reasons other than cushioning technology.

Physical Therapy in Sport, 2002

The purpose of this study was to determine if pelvic restraint during hyperextension on a variabl... more The purpose of this study was to determine if pelvic restraint during hyperextension on a variable angle Roman chair (VARC) changes the muscle activation of the erector spinae musculature. Seventy volunteers (18–35 years) performed hyperextension exercises on the VARC with and without the pelvis restrained. Surface electromyography (EMG) was used to measure the muscle activation of the erector spinae at

International Journal of Exercise Science, 2012

The objective of this review was to analyze the current literature related to the effects of obes... more The objective of this review was to analyze the current literature related to the effects of obesity on balance. These effects were observed during conditions of static balance, perturbed balance and dynamic balance during gait. The literature review included studies focused on the biomechanical effects of obesity, the relationship between weight loss and balance, and the relative efficacy of weight loss as a balance intervention. The older adult population, which faces increased risk of falls and related injuries, was highlighted where targeted research was available. The existing literature provides evidence for a strong link between obesity and balance impairments. This meta-analysis supports the efficacy of weight loss as an intervention to improve balance in the obese. Additional investigations are needed to confirm the reliability of relationships noted in this review paper, and to explore the potential of weight loss in simple and combined interventions. Future research should also determine whether efficacy differs among populations.

Research Quarterly For Exercise and Sport, Mar 1, 2003

Female athletes are at least twice as likely to sustain an anterior cruciate ligament injury than... more Female athletes are at least twice as likely to sustain an anterior cruciate ligament injury than male athletes. The underlying cause of ACL injury is multifactorial. However, several researchers have identified knee joint laxity as a possible contributing factor. The purpose of this study was to provide a comparison of knee joint laxity between male and female collegiate soccer players and male and female non-athletes. Thirty-nine (19 male, 20 female) apparently healthy, collegiate athletes from the University of Texas at El Paso&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s 2001-2002 women&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s intercollegiate soccer team and men&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s club soccer team, and forty (20 male, 20 female) non-athletic students volunteered to participate. All participants were tested bilaterally using the KT-1000 MEDmetric knee joint ligament arthrometer. Three tests were used to determine anterior laxity: passive displacement, active displacement, and the Lachman test. The mean passive displacement, mean active displacement, and Lachman (only for the left leg) were significantly lower for the athletic group than for the non-athletic group. There were no significant differences found between males and females for the passive and active drawer tests. However, females had significantly more laxity than males in the Lachman test. These findings suggest that strength and conditioning may play a more significant role in knee joint laxity than the sex of the individual.

International Journal of Exercise Science Conference Proceedings, 2010

International Journal of Exercise Science Conference Proceedings, 2010

Http Dx Doi Org 10 1080 08924562 2011 10590926, Jan 16, 2013

Isbs Conference Proceedings Archive, Nov 1, 2007

Isbs Conference Proceedings Archive, Oct 28, 2007

The purpose of the study was to compare the cushioning effect of the Nike Air Pegasus 2004 and th... more The purpose of the study was to compare the cushioning effect of the Nike Air Pegasus 2004 and the Spira Volare IITM during running. Measured variables were peak force, peak force relative to body weight and time-to-peak force. It was determined that time-to- peak force was not significantly different (p=0.1745) between the Spira and the Nike. There were significant differences

2007 IEEE 10th International Conference on Rehabilitation Robotics, 2007

Abstract-This paper discusses the design and implementation of a fuzzy inference system for the r... more Abstract-This paper discusses the design and implementation of a fuzzy inference system for the recognition of human gait phases. In particular, this work focuses on using the angles of the joints of lower limb to determine the current stage of a subject's gait cycle. The fuzzy rule-...

Strength and Conditioning Journal, 2007

Research Quarterly for Exercise and Sport, 2012

In this study, we compared hamstring (H) and quadriceps (Q) strength changes in men and women, as... more In this study, we compared hamstring (H) and quadriceps (Q) strength changes in men and women, as well as changes in conventional and functional H:Q ratios following an identical 12-week resistance training program. An isokinetic dynamometer was used to assess 14 male and 14 female participants before and after the intervention, and conventional and functional H:Q ratios were calculated. Hamstring strength improved similarly in men and women, but improvement in quadriceps strength was significantly greater in men, while women showed only modest improvements. For the conventional and functional H:Q ratios, women showed significantly greater improvements than men. Both men and women were able to exceed the commonly recommended 0.6 conventional and 1.0 functional H:Q ratios after the 12-week lower-body resistance training program.

Perceptual and Motor Skills, 2001

The purpose of this study was to provide quantitative data about changes in coordination after pr... more The purpose of this study was to provide quantitative data about changes in coordination after practicing a racquetball forehand drive serve. Novice women (N = 10) were videotaped before and after 10 min. of practicing a racquetball forehand drive serve on Day 1, and after 10-min. practice sessions on consecutive Days 2 through 5. The PEAK5 Motion Measurement System was used to evaluate the following dependent variables: (a) range of motion of the wrist, elbow, upper torso, and pelvis from backswing to ball contact: (b) racket head velocity at ball contact; and (c) coordination. Coordination was evaluated based on analysis of the angular velocity graphs of each performance to assess sequencing and timing of the segmental contributions. Shared positive contribution was assessed between adjacent 2-segment combinations: pelvis-torso and elbow-wrist. A repeated-measures analysis of variance indicated racket velocity, pelvic rotation, and upper torso rotation significantly increased over the 5 days of practice. Although participants increased their pelvic and torso ranges of motion and racket velocity, improvement in coordination was not documented.

The purpose of this study was to compare the cushioning effect of three top rated running shoes a... more The purpose of this study was to compare the cushioning effect of three top rated running shoes and a new spring shoe technology. Shoes were mechanically dropped onto an AMTI force platform. The average in peak forces and the time to peak force were calculated to compare cushioning effect over multiple trials. The Nike and the Spira were found to be significantly better in both cushioning variables than the Adidas and Asics, but not significantly different from each other.

Medicine & Science in Sports & Exercise, 2007

Journal of Physical Education, Recreation & Dance, 2004

Human Movement Science, 2011

This study compared the biomechanical adaptation to running shoe degradation between the dominant... more This study compared the biomechanical adaptation to running shoe degradation between the dominant (D) and non-dominant (ND) leg. Twenty-four runners performed a pre-test in the laboratory, completed 200 miles of road running in a pair of assigned shoes and then returned for a post-test. Kinetic and kinematic data of running in new and worn shoes were collected. Repeated measures ANOVA (Shoe  Leg) were used to analyze temporal, kinetic and kinematic variables (a = .05). A symmetry index (SI) was calculated for the temporal and kinetic variables and paired t-tests were used to compare the SI between shoe conditions. Stance time increased by approximately 7 ms in worn shoes (p = .027). Bilateral differences in the kinematic change (Shoe  Leg interaction) were seen in the torso (p < .05), knee (p < .05), marginally at the hip (p < .10) but not the ankle. No difference in kinetic variables or SI was observed. When running in worn shoes, the torso displayed reduced forward lean for both sides and to a greater extent during the D leg strike. The D hip and knee showed a more extended position for the worn shoe condition while an increased flexion was observed in the ND leg. Most of the kinematic differences observed were small and within the intra-subject variability measured during the same session. Future studies may consider performing a three-dimensional analysis at a higher sample rate and further explore whether asymmetrical adaptation is related to running injuries.

British Journal of Sports Medicine, 2009

In this study, the effect of shoe degradation on running biomechanics by comparing the kinetics a... more In this study, the effect of shoe degradation on running biomechanics by comparing the kinetics and kinematics of running in new and worn shoes was investigated. Three types of footwear using different cushioning technologies were compared. Design: Longitudinal study. Setting: Pre-and post-tests on overground running at 4.5 m s 21 on a 20-m laboratory runway; performance measured using a force platform and a motion capture system. Participants: 24 runners (14 men and 10 women) Interventions: 200 miles of road running in the same pair of shoes. Within-group factor: shoe condition (new/ worn); between-group factor: footwear type (air/gel/ spring). Main outcome measurements: Stance time was calculated from force data. External loads were measured by maximum vertical force and loading rate. Kinematic changes were indicated by sagittal plane angles of the torso, hip, knee and ankle at critical events during the stance phase. Results: Stance time increased (p = 0.035) in worn shoes. The torso displayed less maximum forward lean (p,0.001) and less forward lean at toe-off (p,0.001), while the ankle displayed reduced maximum dorsiflexion (p = 0.013) and increased plantar flexion at toe-off (p,0.001) in worn shoes. No changes in the hip and knee angles. No between-group difference among the three footwear groups or condition by type interaction was found in any measured variables. Conclusions: As shoe cushioning capability decreases, runners modify their patterns to maintain constant external loads. The adaptation strategies to shoe degradation were unaffected by different cushioning technologies, suggesting runners should choose shoes for reasons other than cushioning technology.

Physical Therapy in Sport, 2002

The purpose of this study was to determine if pelvic restraint during hyperextension on a variabl... more The purpose of this study was to determine if pelvic restraint during hyperextension on a variable angle Roman chair (VARC) changes the muscle activation of the erector spinae musculature. Seventy volunteers (18–35 years) performed hyperextension exercises on the VARC with and without the pelvis restrained. Surface electromyography (EMG) was used to measure the muscle activation of the erector spinae at