Adam B. Rosen

Lower Extremity Kinematics During a Drop Jump in Individuals With Patellar Tendinopathy.

Background: Patellar tendinopathy (PT) is a common degenerative condition in physically active populations. Knowledge regarding the biomechanics of landing in populations with symptomatic PT is limited, but altered mechanics may play a role in the development or perpetuation of PT. Purpose: To identify whether study participants with PT exhibited different landing kinematics compared with healthy controls. Study Design: Controlled laboratory study. Methods: Sixty recreationally active participants took part in this study; 30 had current signs and symptoms of PT, including self-reported pain within the patellar tendon during loading activities for at least 3 months and ≤80 on the Victorian Institute of Sport Assessment Scale–Patella (VISA-P). Thirty healthy participants with no history of PT or other knee joint pathology were matched by sex, age, height, and weight. Participants completed 5 trials of a 40-cm, 2-legged drop jump followed immediately by a 50% maximum vertical jump. Dependent variables of interest included hip, knee, and ankle joint angles at initial ground contact, peak angles, and maximum angular displacements during the landing phase in 3 planes. Independent-samples t tests (P ≤ .05) were utilized to compare the joint angles and angular displacements between PT and control participants. Results: Individuals with PT displayed significantly decreased peak hip (PT, 59.2° ± 14.6°; control, 67.2° ± 13.9°; P = .03) and knee flexion angles (PT, 74.8° ± 13.2°; control, 82.5° ± 9.0°; P = .01) compared with control subjects. The PT group displayed decreased maximum angular displacement in the sagittal plane at the hip (PT, 49.3° ± 10.8°; control, 55.2° ± 11.4°; P = .04) and knee (PT, 71.6° ± 8.4°; control, 79.7° ± 8.3°; P < .001) compared with the control group. Conclusion: Participants with PT displayed decreased maximum flexion and angular displacement in the sagittal plane, at both the knee and the hip. The altered movement patterns in those with PT may be perpetuating symptoms associated with PT and could be due to the contributions of the rectus femoris during dynamic movement. Clinical Relevance: Based on kinematic alterations in symptomatic participants, rehabilitation efforts may benefit from focusing on both the knee and the hip to treat symptoms associated with PT.

Comparison Between Single and Combined Clinical Postural Stability Tests in Individuals With and Without Chronic Ankle Instability.

Objective: To determine if a single or/and combined clinical tests match group membership based on self-reported ankle function. Design: Cross-sectional. Setting: Biomechanics Laboratory. Participants: From participants, 58 meeting inclusion/exclusion criteria were divided into a chronic ankle instability (CAI) group (n = 25) who reported ⩽25 on the Cumberland Ankle Instability Tool (CAIT) and a history of moderate–severe ankle sprain(s) and a control group (n = 33) who reported ≥29 on the CAIT and no history of ankle sprain(s). Interventions: Participants completed the following clinical tests: Foot Lift Test (FLT), the Star Excursion Balance Test (SEBT), the Single-Leg Hop Test (SLHT), and the Time in Balance Test (TIB) in a randomized order. A linear regression model was applied to determine measures that matched ankle group membership. Main Outcome Measures: The mean of SEBT reach distance was normalized to percentage leg length. The mean of number of errors in the FLT was recorded. The SLHT and TIB were reported as time in seconds, and the means were calculated. Results: The most parsimonious combination of tests (SLHT and SEBT) resulted in correctly matching 70.69% (41/58) of participants into groups, which was significantly better than chance. The multiple correlation coefficients (R value) for combining the SLHT and SEBT was 0.39. Conclusions: Using SLHT and SEBT resulted in improved recognition of participants designated into the CAI or control groups. Self-report perception of ankle function provides limited information for clinicians and researchers. Using multiple clinical function tests may be more helpful in determining deficits and intervention effectiveness.

Individuals with both perceived ankle instability and mechanical laxity demonstrate dynamic postural stability deficits.

BACKGROUND Chronic ankle instability is a frequent and serious consequence of lateral ankle sprains. The contribution of perceived instability and potential for mechanical laxity to contribute to the overall deficit in dynamic postural stability is unclear. The purpose was to determine if those with mechanical laxity demonstrated significant differences in dynamic postural stability compared to controls, copers and those with perceived instability. METHODS Of 93 participants, 83 recreationally active individuals were divided into 4 groups: controls, copers, those with perceived instability, and those with both perceived instability and mechanical laxity. Injury history and the Cumberland Ankle Instability Tool were collected, and an instrumented arthrometer was applied. Participants completed a single limb jump landing, balancing upon completion. Ground reaction force data were collected, scaled to body mass, and the Dynamic Postural Stability Indices were calculated for anterior-posterior, medial-lateral, vertical and composite. One-way ANOVAs with Tukey post-hoc tests (α<0.05) were conducted on each of the stability indices among the four groups. FINDINGS The mechanically lax group had significantly greater mean (standard deviation) medial-lateral stability index scores 0.57 (0.62) than the coper group 0.24 (0.20; P=0.02) and significantly greater composite index scores 0.73 (0.57) than the perceived instability 0.49 (0.09) and coper groups 0.47 (0.12 P=0.05). No other indices were significantly different among groups. INTERPRETATION Individuals with perceived instability and mechanical laxity exhibited dynamic postural deficits compared to copers and those with perceived instability alone. Mechanical laxity may contribute to the deficits in dynamic postural stability.

Ankle Ligament Laxity and Stiffness in Chronic Ankle Instability

Background: The contribution of mechanical laxity and ligament stiffness to chronic ankle instability is unclear, particularly when using the inversion laxity test, and may have implications for diagnosis, prognosis, and treatment. Our purpose was to determine if individuals with chronic ankle instability demonstrate greater mechanical ligament laxity and altered stiffness compared to controls and copers (those with a healed sprain) during an instrumented arthrometer inversion stress test. Methods: Recreationally active individuals were classified as those with chronic ankle instability (n = 16), copers (n = 16), or controls (n = 16) based on injury history and self-reported score on the Cumberland Ankle Instability Tool (CAIT). Three trials of an inversion stress test were applied with an instrumented arthrometer utilizing a reliable tester. Talocrural inversion (degrees) and stiffness values were extracted. One-way ANOVAs were calculated, and Tukey post hoc testing was applied (α ≤ .05). Results: Groups were not different in age, height, or weight. The chronic ankle instability group (19 ± 6) had significantly lower CAIT scores than the control (30 ± 1) and coper (29 ± 1) groups (P < .001). The chronic ankle instability group (23 ± 12 degrees) demonstrated significantly greater inversion than the controls (13 ± 9 degrees) (P = .04) but was not significantly different than the copers (17 ± 10 degrees). No significant differences were detected in stiffness between the groups. Conclusion: The chronic ankle instability group demonstrated decreased self-reported ankle function and increased mechanical laxity utilizing an instrumented arthrometer for inversion compared to the control group but not the coper group. Laxity, but not stiffness, may be a factor affecting chronic ankle instability and self-reported function. Level of Evidence: Level III, comparative study.

An Evaluation of Portable Wet Bulb Globe Temperature Monitor Accuracy

CONTEXT   Wet bulb globe temperature (WBGT) is the gold standard for assessing environmental heat stress during physical activity. Many manufacturers of commercially available instruments fail to report WBGT accuracy. OBJECTIVE   To determine the accuracy of several commercially available WBGT monitors compared with a standardized reference device. DESIGN   Observational study. SETTING   Field test. PATIENTS OR OTHER PARTICIPANTS   Six commercially available WBGT devices. MAIN OUTCOME MEASURE(S)   Data were recorded for 3 sessions (1 in the morning and 2 in the afternoon) at 2-minute intervals for at least 2 hours. Mean absolute error (MAE), root mean square error (RMSE), mean bias error (MBE), and the Pearson correlation coefficient ( r) were calculated to determine instrument performance compared with the reference unit. RESULTS   The QUESTemp° 34 (MAE = 0.24°C, RMSE = 0.44°C, MBE = -0.64%) and Extech HT30 Heat Stress Wet Bulb Globe Temperature Meter (Extech; MAE = 0.61°C, RMSE = 0.79°C, MBE = 0.44%) demonstrated the least error in relation to the reference standard, whereas the General WBGT8778 Heat Index Checker (General; MAE = 1.18°C, RMSE = 1.34°C, MBE = 4.25%) performed the poorest. The QUESTemp° 34 and Kestrel 4400 Heat Stress Tracker units provided conservative measurements that slightly overestimated the WBGT provided by the reference unit. Finally, instruments using the psychrometric wet bulb temperature (General, REED Heat Index WBGT Meter, and WBGT-103 Heat Stroke Checker) tended to underestimate the WBGT, and the resulting values more frequently fell into WBGT-based activity categories with fewer restrictions as defined by the American College of Sports Medicine. CONCLUSIONS   The QUESTemp° 34, followed by the Extech, had the smallest error compared with the reference unit. Moreover, the QUESTemp° 34, Extech, and Kestrel units appeared to offer conservative yet accurate assessments of the WBGT, potentially minimizing the risk of allowing physical activity to continue in stressful heat environments. Instruments using the psychrometric wet bulb temperature tended to underestimate WBGT under low wind-speed conditions. Accurate WBGT interpretations are important to enable clinicians to guide activities in hot and humid weather conditions.

Attention is associated with postural control in those with chronic ankle instability

Chronic ankle instability (CAI) is often debilitating and may be affected by a number of intrinsic and environmental factors. Alterations in neurocognitive function and attention may contribute to repetitive injury in those with CAI and influence postural control strategies. Thus, the purpose of this study was to determine if there was a difference in attentional functioning and static postural control among groups of Comparison, Coper and CAI participants and assess the relationship between them within each of the groups. Recruited participants performed single-limb balance trials and completed the CNS Vital Signs (CNSVS) computer-based assessment to assess their attentional function. Center of pressure (COP) velocity (COPv) and maximum range (COPr), in both the anteroposterior (AP) and mediolateral (ML) directions were calculated from force plate data. Simple attention (SA), which measures self-regulation and attention control was extracted from the CNSVS. Data from 45 participants (15 in each group, 27=female, 18=male) was analyzed for this study. No significant differences were observed between attention or COP variables among each of the groups. However, significant relationships were present between attention and COP variables within the CAI group. CAI participants displayed significant moderate to large correlations between SA and AP COPr (r=-0.59, p=0.010), AP COPv (r=-0.48, p=0.038) and ML COPr (r=-0.47, p=0.034). The results suggest a linear relationship of stability and attention in the CAI group. Attentional self-regulation may moderate how those with CAI control postural stability. Incorporating neurocognitive training focused on attentional control may improve outcomes in those with CAI.

Cross-cultural adaptation, reliability, and validation of the Korean version of the identification functional ankle instability (IdFAI)

Abstract Purpose: To cross-culturally adapt the Identification Functional Ankle Instability for use with Korean-speaking participants. Methods: The English version of the IdFAI was cross-culturally adapted into Korean based on the guidelines. The psychometric properties in the Korean version of the IdFAI were measured for test-retest reliability, internal consistency, criterion-related validity, discriminative validity, and measurement error 181 native Korean-speakers. Results: Intra-class correlation coefficients (ICC2,1) between the English and Korean versions of the IdFAI for test–retest reliability was 0.98 (standard error of measurement = 1.41). The Cronbach’s alpha coefficient was 0.89 for the Korean versions of IdFAI. The Korean versions of the IdFAI had a strong correlation with the SF-36 (rs = −0.69, p < .001) and the Korean version of the Cumberland Ankle Instability Tool (rs = −0.65, p < .001). The cutoff score of >10 was the optimal cutoff score to distinguish between the group memberships. The minimally detectable change of the Korean versions of the IdFAI score was 3.91. Conclusion: The Korean versions of the IdFAI have shown to be an excellent, reliable, and valid instrument. The Korean versions of the IdFAI can be utilized to assess the presence of Chronic Ankle Instability by researchers and clinicians working among Korean-speaking populations. Implications for rehabilitation The high recurrence rate of sprains may result into Chronic Ankle Instability (CAI). The Identification of Functional Ankle Instability Tool (IdFAI) has been validated and recommended to identify patients with Chronic Ankle Instability (CAI). The Korean version of the Identification of Functional Ankle Instability Tool (IdFAI) may be also recommend to researchers and clinicians for assessing the presence of Chronic Ankle Instability (CAI) in Korean-speaking population.

Functional performance tests identify lateral ankle sprain risk: A prospective pilot study in adolescent soccer players

Determining the clinical utility of functional performance tests (FPTs) and establishing cutoff scores could be useful in identifying those athletes who could benefit from effective injury prevention interventions. Our purpose was to determine the accuracy of FPTs in identifying adolescent athletes who go on to experience lateral ankle sprain(s) and establish specific cutoff scores capable of identifying those who sustain a lateral ankle sprain in the near future. Sixty‐four participants (age = 15.5 ± 1.3 years; height = 161.7 ± 7.7 cm; mass = 57.1 ± 8.4 kg) were recruited from a junior soccer club and tracked for 10 months. Participants performed the anterior (AN), posterior‐medial (PM), and posterior‐lateral (PL) reach directions of the Star Excursion Balance Test (SEBT) and the Single‐Leg Hop Test (SLHT) in pre‐season, and then were followed for the 10‐month competitive season (12 injured, 52 uninjured). Significant Area Under the Curve (AUC) values and cutoff scores were found for the PM (AUC = 0.78; 95% CI 0.61‐0.95; P = 0.003; Sn = 0.83; Sp = 0.77; cutoff = 76%) and the PL (AUC = 0.82; 95% CI 0.71‐0.94; P = 0.001; Sn = 0.92; Sp = 0.65; cutoff = 70%) reach directions of the SEBT and the SLHT (AUC = 0.77; 95% CI 0.60‐0.95; P = 0.003; Sn = 0.67; Sp = 0.94; cutoff = 15.4 seconds). The PM and PL reach directions of the SEBT and the SLHT may be useful as pre‐season screening measures to help clinicians identify adolescents who will go on to experience a lateral ankle sprain.

Functional performance deficits in adolescent athletes with a history of lateral ankle sprain(s)

OBJECTIVE To determine if adolescent athletes with a history of lateral ankle sprain(s) (LAS) displayed deficits on functional performance tests (FPTs) and if deficits on FPT were related to the number of previous LAS. DESIGN Cross-sectional study. SETTING Biomechanics Laboratory. PARTICIPANTS The injured group (n = 24) had a history of ≥1 moderate-severe LAS. The uninjured group (n = 34) had no history of LAS. MAIN OUTCOME MEASURE(S) The average reach distance of three trials in each direction of the star excursion balance test (SEBT) was normalized to leg length (%). The average of two trials of single-leg-hop test (SLHT) was calculated in seconds. RESULTS The injured group performed significantly worse in 3 directions of SEBT than the uninjured group (P < 0.05). SLHT was significantly slower in the injured group compared to the uninjured group (P < 0.05). Statistically significant, strong to moderate inverse relationships were found between the numbers of LAS and each of the three directions of the SEBT (P ≤ 0.01). No relationship was revealed between the number of LAS and the SLHT (P > 0.05). CONCLUSION(S) Adolescent athletes with a history of LAS exhibit functional performance deficits on the SEBT and SLHT. Therefore, the SEBT and SLHT may provide clinicians cost- and time-effective objective tools.

The relationship between acute pain and dynamic postural stability indices in individuals with patellar tendinopathy

BACKGROUND Patellar tendinopathy is a common condition resulting in persistent pain, frequently reported during physical activity. The relationship between dynamic postural stability and pain in these individuals is unclear and how it may affect postural stability. RESEARCH QUESTION Is there a relationship between acute pain and dynamic postural stability indices in individuals with patellar tendinopathy? METHODS Twenty-two recreationally active individuals with patellar tendinopathy participated. Participants performed a two-legged jump and landed on a single test-limb on a force platform. They completed 100 mm visual analogue scales (VAS) before and after landing trials. Anterior-posterior (APSI), medial-lateral (MLSI), vertical (VSI), and composite (DPSI) stability indices were calculated from ground reaction force data. The relationship between stability indices and VAS for pain as well as pain change scores were assessed via non-parametric Spearmans rho (ρ) rank correlations (p≤.05). RESULTS Baseline pain was not significantly correlated with any stability indices. Post-landing pain was significantly correlated with MLSI (ρ = 0.540, p = 0.004) while, VSI (ρ = 0.353, p = 0.053) and DPSI (ρ = 0.347, p = 0.057) had moderate, yet insignificant correlations. Pain change scores demonstrated a large correlation with MLSI (ρ = 0.598, p = 0.002). SIGNIFICANCE As pain increased in individuals with patellar tendinopathy, dynamic postural stability indices values increased, indicating more difficulty transitioning from a dynamic to static state. Although balance deficits are not typically associated with patellar tendinopathy, it appears pain and dynamic postural stability may be related in these individuals.BACKGROUND Patellar tendinopathy is a common condition resulting in persistent pain, frequently reported during physical activity. The relationship between dynamic postural stability and pain in these individuals is unclear and how it may affect postural stability. RESEARCH QUESTION Is there a relationship between acute pain and dynamic postural stability indices in individuals with patellar tendinopathy? METHODS Twenty-two recreationally active individuals with patellar tendinopathy participated. Participants performed a two-legged jump and landed on a single test-limb on a force platform. They completed 100 mm visual analogue scales (VAS) before and after landing trials. Anterior-posterior (APSI), medial-lateral (MLSI), vertical (VSI), and composite (DPSI) stability indices were calculated from ground reaction force data. The relationship between stability indices and VAS for pain as well as pain change scores were assessed via non-parametric Spearmans rho (ρ) rank correlations (p≤.05). RESULTS Baseline pain was not significantly correlated with any stability indices. Post-landing pain was significantly correlated with MLSI (ρ = 0.540, p = 0.004) while, VSI (ρ = 0.353, p = 0.053) and DPSI (ρ = 0.347, p = 0.057) had moderate, yet insignificant correlations. Pain change scores demonstrated a large correlation with MLSI (ρ = 0.598, p = 0.002). SIGNIFICANCE As pain increased in individuals with patellar tendinopathy, dynamic postural stability indices values increased, indicating more difficulty transitioning from a dynamic to static state. Although balance deficits are not typically associated with patellar tendinopathy, it appears pain and dynamic postural stability may be related in these individuals.