Background: Identification of risk factors for lower extremity (LE) injury in sport and military... more Background: Identification of risk factors for lower extremity (LE) injury in sport and military/first-responder occupations is required to inform injury prevention strategies. Objective: To determine if poor movement quality is associated with LE injury in sport and military/first-responder occupations. Material and methods: Five electronic databases were systematically searched. Studies selected included: original data; analytic design; movement quality outcome (qualitative rating of functional compensation, asymmetry, impairment or efficiency of movement control); LE injury sustained with sport or military/first-responder occupation. The PRISMA guidelines were followed. Two independent authors assessed the quality [Downs and Black (DB) criteria] and level of evidence (Oxford Centre of Evidence-Based Medicine model). Results: Of 4361 potential studies, 17 were included. The majority were low quality cohort studies (level 4 evidence). Median DB score was 11/33 (range 3-15). Heterogeneity in methodology and injury definition precluded meta-analyses. The Functional Movement Screen was the most common outcome investigated (15/17 studies). Four studies considered interrelationships between risk factors, seven reported diagnostic accuracy and none tested an intervention program targeting individuals identified as high-risk. There is inconsistent evidence that poor movement quality is associated with increased risk of LE injury in sport and military/first-responder occupations. Conclusions: Future research should focus on high quality cohort studies to identify the most relevant movement quality outcomes for predicting injury risk followed by developing and evaluating pre-participation screening and LE injury prevention programs through high quality randomized controlled trials targeting individuals at greater risk of injury based upon screening tests with validated test properties.
Journal of Strength and Conditioning Research, 2012
Mauntel, TC, Begalle, RL, Cram, TR, Frank, BS, Hirth, CJ, Blackburn, T, and Padua, DA. The effect... more Mauntel, TC, Begalle, RL, Cram, TR, Frank, BS, Hirth, CJ, Blackburn, T, and Padua, DA. The effects of lower extremity muscle activation and passive range of motion on single leg squat performance. J Strength Cond Res 27 : 1813-1823, 2013-Knee valgus is a potential risk factor for lower extremity (LE) injuries. Clinical movement screenings and passive range of motion (PROM) measurements may help identify neuromuscular patterns, which contribute to knee valgus. The purpose of this study was to compare LE muscle activation and PROM between subjects who display visual medial knee displacement (MKD) during a single leg squat (SLS) and those who do not. We hypothesized that muscular activation and PROM would differ between the groups. Forty physically active adults (20 controls, 20 MKDs) participated in this study. Subjects completed 10 LE PROM assessments and performed 5 SLS trials while electromyography (EMG) data were collected from 8 LE muscles. Three separate multivariate analysis of variance were used to identify group differences in EMG data, muscle coactivation, and PROM. Results during the SLS indicated hip coactivation ratios revealed smaller gluteus medius to hip adductor (GMed:Hip Add) (p = 0.028) and gluteus maximus to hip adductor (GMax:Hip Add) coactivation ratios (p = 0.007) compared with the control group. Also, the MKD group displayed significantly less passive ankle dorsiflexion with the knee extended (p = 0.047) and flexed (p = 0.034), and greater talar glide motion (p = 0.012). The findings of this study indicate that MKD during a SLS seems to be influenced by decreased coactivation of the gluteal to the hip adductor muscles and restricted dorsiflexion. Therefore, conditioning, rehabilitation, and injury prevention programs should focus on decreasing hip adductor activity, increasing hip abductor and external rotator activity, and increasing ankle dorsiflexion in hopes to decrease the incidence of these injuries.
International journal of sports physical therapy, 2014
Fatigue has been shown to affect performance of hop tests in patients after anterior cruciate lig... more Fatigue has been shown to affect performance of hop tests in patients after anterior cruciate ligament reconstruction (ACLR) compared to uninjured controls (CTRL). This may render the hop test less sensitive in detecting landing errors. The primary purpose of this study was to investigate the effect of lower extremity fatigue on landing performance assessed with the Landing Error Scoring System (LESS) in patients after ACLR compared to a CTRL group. It is plausible that fatigue would have an effect on confidence and risk appraisal in the ACLR group. The secondary purpose was to determine the relationship between psychological responses and LESS scores after fatigue. Twelve patients following ACLR (6 males, 6 females) who were tested at 10 ± 2.4 months after surgery participated in the current study and were compared to 10 subjects in the control group (5 males, 5 females). Subjects performed a jump-landing task and the landing was assessed using the Landing Error Scoring System (LES...
The authors compared leg stiffness (K VERT ), muscle activation, and joint movement patterns betw... more The authors compared leg stiffness (K VERT ), muscle activation, and joint movement patterns between 11 men and 10 women during hopping. Physically active and healthy men and women performed continuous 2-legged hopping at their preferred rate and at 3.0 Hz. Compared with men, women demonstrated decreased K VERT ; however, after the authors normalized for body mass, gender differences in K VERT were eliminated. In comparison with men, women also demonstrated increased quadriceps and soleus activity, as well as greater quadriceps-to-hamstrings coactivation ratios. There were no significant gender differences for joint movement patterns (p > .05). The relationship between the observed gender differences in muscle recruitment and the increased risk of anterior cruciate ligament injury in women requires further study.
Leg stiffness was compared between age-matched males and females during hopping at preferred and ... more Leg stiffness was compared between age-matched males and females during hopping at preferred and controlled frequencies. Stiffness was defined as the linear regression slope between the vertical center of mass (COM) displacement and ground-reaction forces recorded from a force plate during the stance phase of the hopping task. Results demonstrate that subjects modulated the vertical displacement of the COM during ground contact in relation to the square of hopping frequency. This supports the accuracy of the spring-mass oscillator as a representative model of hopping. It also maintained peak vertical ground-reaction load at approximately three times body weight. Leg stiffness values in males (33.9 ± 8.7kN/m) were significantly (p < 0.01) greater than in females (26.3 ± 6.5kN/m) at each of three hopping frequencies, 3.0, 2.5 Hz, and a preferred hopping rate. In the spring-mass oscillator model leg stiffness and body mass are related to the frequency of motion. Thus male subjects necessarily recruited greater leg stiffness to drive their heavier body mass at the same frequency as the lighter female subjects during the controlled frequency trials. However, in the preferred hopping condition the stiffness was not constrained by the task because frequency was selfselected. Nonetheless, both male and female subjects hopped at statistically similar preferred frequencies (2.34 ± 0.22Hz), therefore, the females continued to demonstrate less leg stiffness. Recognizing the active muscle stiffness contributes to biomechanical stability as well as leg stiffness, these results may provide insight into the gender bias in risk of musculoskeletal knee injury.
Individuals suffering from patellofemoral pain have previously been reported to have decreased is... more Individuals suffering from patellofemoral pain have previously been reported to have decreased isometric strength of the hip musculature; however, no researchers have investigated concentric and eccentric torque of the hip musculature in individuals with patellofemoral pain. To compare concentric and eccentric torque of the hip musculature in individuals with and without patellofemoral pain. Case control. Research laboratory. Twenty participants with patellofemoral pain (age = 26.8 +/- 4.5 years, height = 171.8 +/- 8.4 cm, mass = 72.4 +/- 16.8 kg) and 20 control participants (age = 25.6 +/- 2.8 years, height = 169.5 +/- 8.9 cm, mass = 70.0 +/- 16.9 kg) were tested. Volunteers with patellofemoral pain met the following criteria: knee pain greater than or equal to 3 cm on a 10-cm visual analog scale, insidious onset of symptoms not related to trauma, pain with palpation of the patellar facets, and knee pain during 2 of the following activities: stair climbing, jumping or running, squatting, kneeling, or prolonged sitting. Control participants were excluded if they had a prior history of patellofemoral pain, knee surgery in the past 2 years, or current lower extremity injury that limited participation in physical activity. Concentric and eccentric torque of the hip musculature was measured on an isokinetic dynamometer. All volunteers performed 5 repetitions of each strength test. Separate multivariate analyses of variance were performed to compare concentric and eccentric torque of the hip extensors, abductors, and external rotators between groups. Average and peak concentric and eccentric torque of the hip extensors, abductors, and external rotators. Torque measures were normalized to the participant&amp;amp;amp;amp;#39;s body weight multiplied by height. The patellofemoral pain group was weaker than the control group for peak eccentric hip abduction torque (F(1,38) = 6.630, P = .014), and average concentric (F(1,38) = 4.156, P = .048) and eccentric (F(1,38) = 4.963, P = .032) hip external rotation torque. The patellofemoral pain group displayed weakness in eccentric hip abduction and hip external rotation, which may allow for increased hip adduction and internal rotation during functional movements.
Although mean amplitude and ON-OFF timing of muscle recruitment and electromyography (EMG) activa... more Although mean amplitude and ON-OFF timing of muscle recruitment and electromyography (EMG) activation during gait is achieved by an age of six to eight years in normally developing children, recruitment dynamics illustrated by the shape of the EMG waveform may require continued developmental practice to achieve a stable pattern. Previous analyses have quantified the repeatability of the EMG waveform in adult subjects, but EMG variability for a pediatric population may be significantly different. The goal of this study was to quantify intra-session and inter-session variability in the phasic EMG waveform patterns from the lower limb muscles during self-selected speeds of walking in healthy-normal children for comparison with adult variability in gait EMG. The variance ratio quantifies the repeatability of the integrated EMG waveform shape in a group of normally-developing children. Results reveal that between-session EMG waveform variability were similar in adult and pediatric populations, but within-session variability for the children was approximately twice the published value for adults. Clinical implications of this pediatric EMG variability suggest cautious interpretation of data from limited trial samples or inter-session changes in performance of gait data.
The objective of this study was to utilise an ultrasonic technique to assess the effect of patell... more The objective of this study was to utilise an ultrasonic technique to assess the effect of patellofemoral pain syndrome (PFPS) on the mechanical properties of the patellar tendon. Seven subjects with PFPS and seven matched control subjects volunteered to participate in this study. ...
Background: Supraspinatus strengthening is an important component of shoulder rehabilitation. Pre... more Background: Supraspinatus strengthening is an important component of shoulder rehabilitation. Previous work has determined that the full-can and empty-can exercises elicit the greatest amount of supraspinatus activity. However, scapular kinematics has not been considered when prescribing supraspinatus exercises.
Identifying neuromuscular screening factors for anterior cruciate ligament (ACL) injury is a cr... more Identifying neuromuscular screening factors for anterior cruciate ligament (ACL) injury is a critical step toward large-scale deployment of effective ACL-injury-prevention programs. The Landing Error Scoring System (LESS) is a valid and reliable clinical assessment of jump-landing biomechanics. To investigate the ability of the LESS to identify individuals at risk for ACL injury in an elite-youth soccer population. Cohort study. Field-based functional movement screening performed at soccer practice facilities. A total of 829 elite-youth soccer athletes (348 boys, 481 girls; age = 13.9 ± 1.8 years, age range = 11 to 18 years), of whom 25% (n = 207) were less than 13 years of age. Baseline preseason testing for all participants consisted of a jump-landing task (3 trials). Participants were followed prospectively throughout their soccer seasons for diagnosis of ACL injuries (1217 athlete-seasons of follow-up). Landings were scored for "errors" in technique using...
Despite evolutionary changes in protective equipment, head injury remains common in football. We ... more Despite evolutionary changes in protective equipment, head injury remains common in football. We investigated concussion in football and associated epidemiologic issues such as 1) incidence of injury, 2) common signs and symptoms, and 3) patterns in making return-to-play decisions. We received 242 of 392 surveys (62%) that were sent to high school and collegiate certified athletic trainers at the beginning of three football seasons. Of the 17,549 football players represented, 888 (5.1%) sustained at least one concussion, and 131 (14.7% of the 888) sustained a second injury during the same season. The greatest incidence of concussion was found at the high school (5.6%) and collegiate division III (5.5%) levels, suggesting that there is an association between level of play and the proportion of players injured. Players who sustained one concussion in a season were three times more likely to sustain a second concussion in the same season compared with uninjured players. Contact with ar...
Corresponding Author Information Corresponding author at: Center for Human Movement Science, Divi... more Corresponding Author Information Corresponding author at: Center for Human Movement Science, Division of Physical Therapy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. Tel.:+ 1 919 843 8643; fax:+ 1 919 966 3678.
Poor freestyle stroke biomechanics is a suggested risk factor for shoulder pain and pathology, bu... more Poor freestyle stroke biomechanics is a suggested risk factor for shoulder pain and pathology, but this has not been proven in biomechanical or clinical studies. Furthermore, the prevalence of these theoretical errors has not been identified, which would help coaches, athletic trainers, and researchers determine the most appropriate errors to focus on and develop interventions. The majority of swimmers will present with at least 1 freestyle stroke error. Cross-sectional study. Level 4. Stroke biomechanics for 31 swimmers from a collegiate swimming team were captured using underwater/above-water cameras. Each video was evaluated for biomechanical errors: a dropped elbow during the pull-through phase, a dropped elbow during the recovery phase, an eyes-forward head-carrying angle, incorrect hand position during hand entry, incorrect hand entry angle, incorrect pull-through pattern, and inadequate body roll. Error prevalence was calculated, and relationships among the errors were evalua...
Journal of science and medicine in sport / Sports Medicine Australia, Jan 25, 2014
Evaluate the effect of a anterior cruciate ligament injury prevention program coaching workshop o... more Evaluate the effect of a anterior cruciate ligament injury prevention program coaching workshop on elite-level youth soccer coaches' behavioral determinants to implement a injury prevention program and describe coaches' subsequent injury prevention program implementation compliance. Descriptive study. We evaluated a soccer club's coaches' behavioral determinants regarding injury prevention programming implementation before and after a coaching workshop using pre- and post-workshop surveys. We then described the club's coaches' subsequent adoption of and implementation compliance with the injury prevention programming during the following season. The injury prevention workshop increased coaches' attitudes toward conducting a program at the beginning of practice (p<0.05), substituting the program for a warm-up prior to practice (p<0.05), and improving player cutting and landing technique by implementing the program (p<0.05). The injury prevention p...
Ankle-dorsiflexion (DF) range of motion (ROM) may influence movement variables that are known to ... more Ankle-dorsiflexion (DF) range of motion (ROM) may influence movement variables that are known to affect anterior cruciate ligament loading, such as knee valgus and knee flexion. To our knowledge, researchers have not studied individuals with limited or normal ankle DF-ROM to investigate the relationship between those factors and the lower extremity movement patterns associated with anterior cruciate ligament injury. To determine, using 2 different measurement techniques, whether knee- and ankle-joint kinematics differ between participants with limited and normal ankle DF-ROM. Cross-sectional study. Sports medicine research laboratory. Forty physically active adults (20 with limited ankle DF-ROM, 20 with normal ankle DF-ROM). Ankle DF-ROM was assessed using 2 techniques: (1) nonweight-bearing ankle DF-ROM with the knee straight, and (2) weight-bearing lunge (WBL). Knee flexion, knee valgus-varus, knee internal-external rotation, and ankle DF displacements were assessed during the ove...
There is a need for reliable clinical assessment tools that can be used to identify individuals w... more There is a need for reliable clinical assessment tools that can be used to identify individuals who may be at risk for injury. The Landing Error Scoring System (LESS) is a reliable and valid clinical assessment tool that was developed to identify individuals at risk for lower extremity injuries. One limitation of this tool is that it cannot be assessed in real time and requires the use of video cameras. To determine the interrater reliability of a real-time version of the LESS, the LESS-RT. Reliability study. Controlled research laboratory. 43 healthy volunteers (24 women, 19 men) between the ages of 18 and 23. The LESS-RT evaluates 10 jump-landing characteristics that may predispose an individual to lower extremity injuries. Two sets of raters used the LESS-RT to evaluate participants as they performed 4 trials of a jump-landing task. Intraclass correlation coefficient (ICC2,1) values for the final composite score of the LESS-RT were calculated to assess interrater reliability of t...
Information as to how anterior cruciate ligament (ACL) injury and reconstructive surgery (ACLR) a... more Information as to how anterior cruciate ligament (ACL) injury and reconstructive surgery (ACLR) alter lower extremity biomechanics may improve rehabilitation and return to play guidelines, reducing the risk for repeat ACL injury. To compare lower extremity biomechanics before ACL injury and after subsequent ACLR for the injured and uninjured leg. Baseline unilateral lower extremity biomechanics were collected on the dominant leg of participants without ACL injury when they entered the Joint Undertaking to Monitor and Prevent ACL (JUMP-ACL) study. Thirty-one participants with subsequent ACL injury, reconstructive surgery and full return to physical activity completed repeat, follow-up biomechanical testing, as did 39 uninjured, matched controls. Not all injured participants suffered injury to the dominant leg, requiring separation of those with ACL injury into two groups: ACLR-injured leg group (n=12) and ACLR-uninjured leg group (n=19). We compared the landing biomechanics of these ...
Context: Clinicians commonly attempt to facilitate vastus medialis oblique (VMO) activity by inst... more Context: Clinicians commonly attempt to facilitate vastus medialis oblique (VMO) activity by instructing patients to squeeze a ball between their knees during squatting exercises. Objective: To determine whether VMO activation amplitude and the VMO to vastus lateralis (VL) activation ratio (VMO:VL) were altered when performing active hip adduction during a dynamic squat exercise. Design: Single test session. Participants: Fifteen healthy
Background: Identification of risk factors for lower extremity (LE) injury in sport and military... more Background: Identification of risk factors for lower extremity (LE) injury in sport and military/first-responder occupations is required to inform injury prevention strategies. Objective: To determine if poor movement quality is associated with LE injury in sport and military/first-responder occupations. Material and methods: Five electronic databases were systematically searched. Studies selected included: original data; analytic design; movement quality outcome (qualitative rating of functional compensation, asymmetry, impairment or efficiency of movement control); LE injury sustained with sport or military/first-responder occupation. The PRISMA guidelines were followed. Two independent authors assessed the quality [Downs and Black (DB) criteria] and level of evidence (Oxford Centre of Evidence-Based Medicine model). Results: Of 4361 potential studies, 17 were included. The majority were low quality cohort studies (level 4 evidence). Median DB score was 11/33 (range 3-15). Heterogeneity in methodology and injury definition precluded meta-analyses. The Functional Movement Screen was the most common outcome investigated (15/17 studies). Four studies considered interrelationships between risk factors, seven reported diagnostic accuracy and none tested an intervention program targeting individuals identified as high-risk. There is inconsistent evidence that poor movement quality is associated with increased risk of LE injury in sport and military/first-responder occupations. Conclusions: Future research should focus on high quality cohort studies to identify the most relevant movement quality outcomes for predicting injury risk followed by developing and evaluating pre-participation screening and LE injury prevention programs through high quality randomized controlled trials targeting individuals at greater risk of injury based upon screening tests with validated test properties.
Journal of Strength and Conditioning Research, 2012
Mauntel, TC, Begalle, RL, Cram, TR, Frank, BS, Hirth, CJ, Blackburn, T, and Padua, DA. The effect... more Mauntel, TC, Begalle, RL, Cram, TR, Frank, BS, Hirth, CJ, Blackburn, T, and Padua, DA. The effects of lower extremity muscle activation and passive range of motion on single leg squat performance. J Strength Cond Res 27 : 1813-1823, 2013-Knee valgus is a potential risk factor for lower extremity (LE) injuries. Clinical movement screenings and passive range of motion (PROM) measurements may help identify neuromuscular patterns, which contribute to knee valgus. The purpose of this study was to compare LE muscle activation and PROM between subjects who display visual medial knee displacement (MKD) during a single leg squat (SLS) and those who do not. We hypothesized that muscular activation and PROM would differ between the groups. Forty physically active adults (20 controls, 20 MKDs) participated in this study. Subjects completed 10 LE PROM assessments and performed 5 SLS trials while electromyography (EMG) data were collected from 8 LE muscles. Three separate multivariate analysis of variance were used to identify group differences in EMG data, muscle coactivation, and PROM. Results during the SLS indicated hip coactivation ratios revealed smaller gluteus medius to hip adductor (GMed:Hip Add) (p = 0.028) and gluteus maximus to hip adductor (GMax:Hip Add) coactivation ratios (p = 0.007) compared with the control group. Also, the MKD group displayed significantly less passive ankle dorsiflexion with the knee extended (p = 0.047) and flexed (p = 0.034), and greater talar glide motion (p = 0.012). The findings of this study indicate that MKD during a SLS seems to be influenced by decreased coactivation of the gluteal to the hip adductor muscles and restricted dorsiflexion. Therefore, conditioning, rehabilitation, and injury prevention programs should focus on decreasing hip adductor activity, increasing hip abductor and external rotator activity, and increasing ankle dorsiflexion in hopes to decrease the incidence of these injuries.
International journal of sports physical therapy, 2014
Fatigue has been shown to affect performance of hop tests in patients after anterior cruciate lig... more Fatigue has been shown to affect performance of hop tests in patients after anterior cruciate ligament reconstruction (ACLR) compared to uninjured controls (CTRL). This may render the hop test less sensitive in detecting landing errors. The primary purpose of this study was to investigate the effect of lower extremity fatigue on landing performance assessed with the Landing Error Scoring System (LESS) in patients after ACLR compared to a CTRL group. It is plausible that fatigue would have an effect on confidence and risk appraisal in the ACLR group. The secondary purpose was to determine the relationship between psychological responses and LESS scores after fatigue. Twelve patients following ACLR (6 males, 6 females) who were tested at 10 ± 2.4 months after surgery participated in the current study and were compared to 10 subjects in the control group (5 males, 5 females). Subjects performed a jump-landing task and the landing was assessed using the Landing Error Scoring System (LES...
The authors compared leg stiffness (K VERT ), muscle activation, and joint movement patterns betw... more The authors compared leg stiffness (K VERT ), muscle activation, and joint movement patterns between 11 men and 10 women during hopping. Physically active and healthy men and women performed continuous 2-legged hopping at their preferred rate and at 3.0 Hz. Compared with men, women demonstrated decreased K VERT ; however, after the authors normalized for body mass, gender differences in K VERT were eliminated. In comparison with men, women also demonstrated increased quadriceps and soleus activity, as well as greater quadriceps-to-hamstrings coactivation ratios. There were no significant gender differences for joint movement patterns (p > .05). The relationship between the observed gender differences in muscle recruitment and the increased risk of anterior cruciate ligament injury in women requires further study.
Leg stiffness was compared between age-matched males and females during hopping at preferred and ... more Leg stiffness was compared between age-matched males and females during hopping at preferred and controlled frequencies. Stiffness was defined as the linear regression slope between the vertical center of mass (COM) displacement and ground-reaction forces recorded from a force plate during the stance phase of the hopping task. Results demonstrate that subjects modulated the vertical displacement of the COM during ground contact in relation to the square of hopping frequency. This supports the accuracy of the spring-mass oscillator as a representative model of hopping. It also maintained peak vertical ground-reaction load at approximately three times body weight. Leg stiffness values in males (33.9 ± 8.7kN/m) were significantly (p < 0.01) greater than in females (26.3 ± 6.5kN/m) at each of three hopping frequencies, 3.0, 2.5 Hz, and a preferred hopping rate. In the spring-mass oscillator model leg stiffness and body mass are related to the frequency of motion. Thus male subjects necessarily recruited greater leg stiffness to drive their heavier body mass at the same frequency as the lighter female subjects during the controlled frequency trials. However, in the preferred hopping condition the stiffness was not constrained by the task because frequency was selfselected. Nonetheless, both male and female subjects hopped at statistically similar preferred frequencies (2.34 ± 0.22Hz), therefore, the females continued to demonstrate less leg stiffness. Recognizing the active muscle stiffness contributes to biomechanical stability as well as leg stiffness, these results may provide insight into the gender bias in risk of musculoskeletal knee injury.
Individuals suffering from patellofemoral pain have previously been reported to have decreased is... more Individuals suffering from patellofemoral pain have previously been reported to have decreased isometric strength of the hip musculature; however, no researchers have investigated concentric and eccentric torque of the hip musculature in individuals with patellofemoral pain. To compare concentric and eccentric torque of the hip musculature in individuals with and without patellofemoral pain. Case control. Research laboratory. Twenty participants with patellofemoral pain (age = 26.8 +/- 4.5 years, height = 171.8 +/- 8.4 cm, mass = 72.4 +/- 16.8 kg) and 20 control participants (age = 25.6 +/- 2.8 years, height = 169.5 +/- 8.9 cm, mass = 70.0 +/- 16.9 kg) were tested. Volunteers with patellofemoral pain met the following criteria: knee pain greater than or equal to 3 cm on a 10-cm visual analog scale, insidious onset of symptoms not related to trauma, pain with palpation of the patellar facets, and knee pain during 2 of the following activities: stair climbing, jumping or running, squatting, kneeling, or prolonged sitting. Control participants were excluded if they had a prior history of patellofemoral pain, knee surgery in the past 2 years, or current lower extremity injury that limited participation in physical activity. Concentric and eccentric torque of the hip musculature was measured on an isokinetic dynamometer. All volunteers performed 5 repetitions of each strength test. Separate multivariate analyses of variance were performed to compare concentric and eccentric torque of the hip extensors, abductors, and external rotators between groups. Average and peak concentric and eccentric torque of the hip extensors, abductors, and external rotators. Torque measures were normalized to the participant&amp;amp;amp;amp;#39;s body weight multiplied by height. The patellofemoral pain group was weaker than the control group for peak eccentric hip abduction torque (F(1,38) = 6.630, P = .014), and average concentric (F(1,38) = 4.156, P = .048) and eccentric (F(1,38) = 4.963, P = .032) hip external rotation torque. The patellofemoral pain group displayed weakness in eccentric hip abduction and hip external rotation, which may allow for increased hip adduction and internal rotation during functional movements.
Although mean amplitude and ON-OFF timing of muscle recruitment and electromyography (EMG) activa... more Although mean amplitude and ON-OFF timing of muscle recruitment and electromyography (EMG) activation during gait is achieved by an age of six to eight years in normally developing children, recruitment dynamics illustrated by the shape of the EMG waveform may require continued developmental practice to achieve a stable pattern. Previous analyses have quantified the repeatability of the EMG waveform in adult subjects, but EMG variability for a pediatric population may be significantly different. The goal of this study was to quantify intra-session and inter-session variability in the phasic EMG waveform patterns from the lower limb muscles during self-selected speeds of walking in healthy-normal children for comparison with adult variability in gait EMG. The variance ratio quantifies the repeatability of the integrated EMG waveform shape in a group of normally-developing children. Results reveal that between-session EMG waveform variability were similar in adult and pediatric populations, but within-session variability for the children was approximately twice the published value for adults. Clinical implications of this pediatric EMG variability suggest cautious interpretation of data from limited trial samples or inter-session changes in performance of gait data.
The objective of this study was to utilise an ultrasonic technique to assess the effect of patell... more The objective of this study was to utilise an ultrasonic technique to assess the effect of patellofemoral pain syndrome (PFPS) on the mechanical properties of the patellar tendon. Seven subjects with PFPS and seven matched control subjects volunteered to participate in this study. ...
Background: Supraspinatus strengthening is an important component of shoulder rehabilitation. Pre... more Background: Supraspinatus strengthening is an important component of shoulder rehabilitation. Previous work has determined that the full-can and empty-can exercises elicit the greatest amount of supraspinatus activity. However, scapular kinematics has not been considered when prescribing supraspinatus exercises.
Identifying neuromuscular screening factors for anterior cruciate ligament (ACL) injury is a cr... more Identifying neuromuscular screening factors for anterior cruciate ligament (ACL) injury is a critical step toward large-scale deployment of effective ACL-injury-prevention programs. The Landing Error Scoring System (LESS) is a valid and reliable clinical assessment of jump-landing biomechanics. To investigate the ability of the LESS to identify individuals at risk for ACL injury in an elite-youth soccer population. Cohort study. Field-based functional movement screening performed at soccer practice facilities. A total of 829 elite-youth soccer athletes (348 boys, 481 girls; age = 13.9 ± 1.8 years, age range = 11 to 18 years), of whom 25% (n = 207) were less than 13 years of age. Baseline preseason testing for all participants consisted of a jump-landing task (3 trials). Participants were followed prospectively throughout their soccer seasons for diagnosis of ACL injuries (1217 athlete-seasons of follow-up). Landings were scored for "errors" in technique using...
Despite evolutionary changes in protective equipment, head injury remains common in football. We ... more Despite evolutionary changes in protective equipment, head injury remains common in football. We investigated concussion in football and associated epidemiologic issues such as 1) incidence of injury, 2) common signs and symptoms, and 3) patterns in making return-to-play decisions. We received 242 of 392 surveys (62%) that were sent to high school and collegiate certified athletic trainers at the beginning of three football seasons. Of the 17,549 football players represented, 888 (5.1%) sustained at least one concussion, and 131 (14.7% of the 888) sustained a second injury during the same season. The greatest incidence of concussion was found at the high school (5.6%) and collegiate division III (5.5%) levels, suggesting that there is an association between level of play and the proportion of players injured. Players who sustained one concussion in a season were three times more likely to sustain a second concussion in the same season compared with uninjured players. Contact with ar...
Corresponding Author Information Corresponding author at: Center for Human Movement Science, Divi... more Corresponding Author Information Corresponding author at: Center for Human Movement Science, Division of Physical Therapy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. Tel.:+ 1 919 843 8643; fax:+ 1 919 966 3678.
Poor freestyle stroke biomechanics is a suggested risk factor for shoulder pain and pathology, bu... more Poor freestyle stroke biomechanics is a suggested risk factor for shoulder pain and pathology, but this has not been proven in biomechanical or clinical studies. Furthermore, the prevalence of these theoretical errors has not been identified, which would help coaches, athletic trainers, and researchers determine the most appropriate errors to focus on and develop interventions. The majority of swimmers will present with at least 1 freestyle stroke error. Cross-sectional study. Level 4. Stroke biomechanics for 31 swimmers from a collegiate swimming team were captured using underwater/above-water cameras. Each video was evaluated for biomechanical errors: a dropped elbow during the pull-through phase, a dropped elbow during the recovery phase, an eyes-forward head-carrying angle, incorrect hand position during hand entry, incorrect hand entry angle, incorrect pull-through pattern, and inadequate body roll. Error prevalence was calculated, and relationships among the errors were evalua...
Journal of science and medicine in sport / Sports Medicine Australia, Jan 25, 2014
Evaluate the effect of a anterior cruciate ligament injury prevention program coaching workshop o... more Evaluate the effect of a anterior cruciate ligament injury prevention program coaching workshop on elite-level youth soccer coaches' behavioral determinants to implement a injury prevention program and describe coaches' subsequent injury prevention program implementation compliance. Descriptive study. We evaluated a soccer club's coaches' behavioral determinants regarding injury prevention programming implementation before and after a coaching workshop using pre- and post-workshop surveys. We then described the club's coaches' subsequent adoption of and implementation compliance with the injury prevention programming during the following season. The injury prevention workshop increased coaches' attitudes toward conducting a program at the beginning of practice (p<0.05), substituting the program for a warm-up prior to practice (p<0.05), and improving player cutting and landing technique by implementing the program (p<0.05). The injury prevention p...
Ankle-dorsiflexion (DF) range of motion (ROM) may influence movement variables that are known to ... more Ankle-dorsiflexion (DF) range of motion (ROM) may influence movement variables that are known to affect anterior cruciate ligament loading, such as knee valgus and knee flexion. To our knowledge, researchers have not studied individuals with limited or normal ankle DF-ROM to investigate the relationship between those factors and the lower extremity movement patterns associated with anterior cruciate ligament injury. To determine, using 2 different measurement techniques, whether knee- and ankle-joint kinematics differ between participants with limited and normal ankle DF-ROM. Cross-sectional study. Sports medicine research laboratory. Forty physically active adults (20 with limited ankle DF-ROM, 20 with normal ankle DF-ROM). Ankle DF-ROM was assessed using 2 techniques: (1) nonweight-bearing ankle DF-ROM with the knee straight, and (2) weight-bearing lunge (WBL). Knee flexion, knee valgus-varus, knee internal-external rotation, and ankle DF displacements were assessed during the ove...
There is a need for reliable clinical assessment tools that can be used to identify individuals w... more There is a need for reliable clinical assessment tools that can be used to identify individuals who may be at risk for injury. The Landing Error Scoring System (LESS) is a reliable and valid clinical assessment tool that was developed to identify individuals at risk for lower extremity injuries. One limitation of this tool is that it cannot be assessed in real time and requires the use of video cameras. To determine the interrater reliability of a real-time version of the LESS, the LESS-RT. Reliability study. Controlled research laboratory. 43 healthy volunteers (24 women, 19 men) between the ages of 18 and 23. The LESS-RT evaluates 10 jump-landing characteristics that may predispose an individual to lower extremity injuries. Two sets of raters used the LESS-RT to evaluate participants as they performed 4 trials of a jump-landing task. Intraclass correlation coefficient (ICC2,1) values for the final composite score of the LESS-RT were calculated to assess interrater reliability of t...
Information as to how anterior cruciate ligament (ACL) injury and reconstructive surgery (ACLR) a... more Information as to how anterior cruciate ligament (ACL) injury and reconstructive surgery (ACLR) alter lower extremity biomechanics may improve rehabilitation and return to play guidelines, reducing the risk for repeat ACL injury. To compare lower extremity biomechanics before ACL injury and after subsequent ACLR for the injured and uninjured leg. Baseline unilateral lower extremity biomechanics were collected on the dominant leg of participants without ACL injury when they entered the Joint Undertaking to Monitor and Prevent ACL (JUMP-ACL) study. Thirty-one participants with subsequent ACL injury, reconstructive surgery and full return to physical activity completed repeat, follow-up biomechanical testing, as did 39 uninjured, matched controls. Not all injured participants suffered injury to the dominant leg, requiring separation of those with ACL injury into two groups: ACLR-injured leg group (n=12) and ACLR-uninjured leg group (n=19). We compared the landing biomechanics of these ...
Context: Clinicians commonly attempt to facilitate vastus medialis oblique (VMO) activity by inst... more Context: Clinicians commonly attempt to facilitate vastus medialis oblique (VMO) activity by instructing patients to squeeze a ball between their knees during squatting exercises. Objective: To determine whether VMO activation amplitude and the VMO to vastus lateralis (VL) activation ratio (VMO:VL) were altered when performing active hip adduction during a dynamic squat exercise. Design: Single test session. Participants: Fifteen healthy
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Papers by Darin Padua
Objective: To determine if poor movement quality is associated with LE injury in sport and military/first-responder occupations.
Material and methods: Five electronic databases were systematically searched. Studies selected included: original data; analytic design; movement quality outcome (qualitative rating of functional compensation, asymmetry, impairment or efficiency of movement control); LE injury sustained with sport or military/first-responder occupation. The PRISMA guidelines were followed. Two independent authors assessed the quality [Downs and Black (DB) criteria] and level of evidence (Oxford Centre of Evidence-Based Medicine model).
Results: Of 4361 potential studies, 17 were included. The majority were low quality cohort studies (level 4 evidence). Median DB score was 11/33 (range 3-15). Heterogeneity in methodology and injury definition precluded meta-analyses. The Functional Movement Screen was the most common outcome investigated (15/17 studies). Four studies considered interrelationships between risk factors, seven reported diagnostic accuracy and none tested an intervention program targeting individuals identified as high-risk. There is inconsistent evidence that poor movement quality is associated with increased risk of LE injury in sport and military/first-responder occupations.
Conclusions: Future research should focus on high quality cohort studies to identify the most relevant movement quality outcomes for predicting injury risk followed by developing and evaluating pre-participation screening and LE injury prevention programs through high quality randomized controlled trials targeting individuals at greater risk of injury based upon screening tests with validated test properties.
Objective: To determine if poor movement quality is associated with LE injury in sport and military/first-responder occupations.
Material and methods: Five electronic databases were systematically searched. Studies selected included: original data; analytic design; movement quality outcome (qualitative rating of functional compensation, asymmetry, impairment or efficiency of movement control); LE injury sustained with sport or military/first-responder occupation. The PRISMA guidelines were followed. Two independent authors assessed the quality [Downs and Black (DB) criteria] and level of evidence (Oxford Centre of Evidence-Based Medicine model).
Results: Of 4361 potential studies, 17 were included. The majority were low quality cohort studies (level 4 evidence). Median DB score was 11/33 (range 3-15). Heterogeneity in methodology and injury definition precluded meta-analyses. The Functional Movement Screen was the most common outcome investigated (15/17 studies). Four studies considered interrelationships between risk factors, seven reported diagnostic accuracy and none tested an intervention program targeting individuals identified as high-risk. There is inconsistent evidence that poor movement quality is associated with increased risk of LE injury in sport and military/first-responder occupations.
Conclusions: Future research should focus on high quality cohort studies to identify the most relevant movement quality outcomes for predicting injury risk followed by developing and evaluating pre-participation screening and LE injury prevention programs through high quality randomized controlled trials targeting individuals at greater risk of injury based upon screening tests with validated test properties.