CHRONIC ANKLE INSTABILITY AND AGING

Lateral ankle sprains are the most common musculoskeletal injury among the general population and U.S. military personnel. Despite the common perception of being a minor injury, at least 1 out of 3 individuals with a previous ankle sprain will develop chronic ankle instability (CAI). This clinical phenomenon creates a significant barrier for patients to return to their prior level of physical function. Specifically, CAI is associated with reductions in physical activity level, leading to decreases in lower health-related quality of life and increase risk of developing of post-traumatic ankle osteoarthritis. Current evidence has largely focused on characterizing the mechanical and sensorimotor insufficiencies associated with CAI in adolescent and young-adult populations, with little attention on middle- and older-aged adults. This restricts our understanding of how these insufficiencies associated with CAI that develop in early adulthood progress over time and contribute to other chronic diseases such as post-traumatic osteoarthritis. Therefore, the overall objective of this study was to compare self-reported and physical function between three age groups: 1) young, 2) middle-aged, and 3) older-aged adults with and without CAI. We hypothesized participants with CAI would have age-related changes in self-reported and physical function compared to non-injured individuals across the lifespan. The objective of this dissertation was to compare regional and global health- related quality of life (HRQoL), static and dynamic balance, spinal reflex excitability of the soleus muscle, open- and closed-kinetic chain dorsiflexion range of motion and spatiotemporal gait parameters between those with and without CAI across the lifespan. Her callIt was hypothesized that all self-reported and physical characteristics would be decrease with age, but significantly more in those with CAI compare to non-injured individuals. Results from the first study demonstrated participants with CAI had worse regional HRQoL compared to healthy-controls as evidenced by the lower Foot and Ankle Disability Index scores. Likewise, participants with CAI reported having worse overall physical function and pain interference during activity compared to healthy-controls. There was no significant interaction for Injury (CAI and healthy-control) and Age group (young, middle, and old) for any dependent variable. In the second, it was determined that static and dynamic balance, spinal reflex excitability, ankle (dorsiflexion and plantarflexion) and hip extension torque were all lower in the older-aged participants compared to the younger-aged adults. In addition, it was determined that participants with CAI had decreased dorsiflexion range of motion, ankle (dorsiflexion and plantar flexion) and hip extension peak isometric torque compared to the healthy-control group. However, no significant interaction was found for Injury (CAI & healthy-control) and Age (young, middle, old) for any dependent variable. In the third study, there were no differences in spatiotemporal gait parameters between groups (CAI vs. healthy-controls) or age categories. It can be concluded from this dissertation that regardless of the age, individuals with CAI have worse region-specific HRQoL, lower overall physical function, greater pain interference, limited dorsiflexion range of motion, and decreased ankle and hip peak isometric torque compared to healthy-controls. Several age-related observations were found including decreased static and dynamic balance, ankle and hip strength, and spinal reflex excitability. Though no relationship was found between CAI and age, several interactions were found to be trending towards significance. Therefore, future work is needed to better understand the consequences of CAI on middle- and older-aged adults

Corticospinal Activity During A Single-Leg Stance In People With Chronic Ankle Instability

Purpose: The aim of the study was to determine whether corticospinal excitability and inhibition of the tibialis anterior during single-leg standing differs among individuals with chronic ankle instability (CAI), lateral ankle sprain copers, and healthy controls. Methods: Twenty-three participants with CAI, 23 lateral ankle sprain copers, and 24 healthy control participants volunteered. Active motor threshold (AMT), normalized motor-evoked potential (MEP), and cortical silent period (CSP) were evaluated by transcranial magnetic stimulation while participants performed a single-leg standing task. Results: Participants with CAI had significantly longer CSP at 100% of AMT and lower normalized MEP at 120% of AMT compared to lateral ankle sprain copers (CSP100%: p = 0.003, MEP120%: p = 0.044) and controls (CSP 100%: p = 0.041, MEP120%: p = 0.006). Conclusion: This investigation demonstrated altered corticospinal excitability and inhibition of the tibialis anterior during single-leg standing in participants with CAI. Further research is needed to examine the effects of corticospinal maladaptations to motor control of the tibial anterior on postural control performance in those with CAI

Corticospinal Activity during a Single-Leg Stance in People with Chronic Ankle Instability

PURPOSE: The aim of the study was to determine whether corticospinal excitability and inhibition of the tibialis anterior during single-leg standing differs among individuals with chronic ankle instability (CAI), lateral ankle sprain copers, and healthy controls. METHODS: Twenty-three participants with CAI, 23 lateral ankle sprain copers, and 24 healthy control participants volunteered. Active motor threshold (AMT), normalized motor-evoked potential (MEP), and cortical silent period (CSP) were evaluated by transcranial magnetic stimulation while participants performed a single-leg standing task. RESULTS: Participants with CAI had significantly longer CSP at 100% of AMT and lower normalized MEP at 120% of AMT compared to lateral ankle sprain copers (CSP100%: p = 0.003; MEP120%: p = 0.044) and controls (CSP100%: p = 0.041; MEP120%: p = 0.006). CONCLUSION: This investigation demonstrated altered corticospinal excitability and inhibition of the tibialis anterior during single-leg standing in participants with CAI. Further research is needed to examine the effects of corticospinal maladaptations to motor control of the tibial anterior on postural control performance in those with CAI

Opioid and Non-Opioid Prescribing Rates for Ankle Fractures in Emergency Departments across the United States between 2006 and 2015

This presentation describes the percentage of patients prescribed a controlled and non-controlled medication in an United States Emergency Department for a diagnosed ankle fracture

Opioid and Non-Opioid Prescribing Rates for Ankle Fractures in Emergency Departments Across the United States Between 2006 and 2015

Context: An ankle fracture is a common injury observed in the Emergency Department (ED) and is often treated conservatively or surgically, depending on whether the fracture is stable. Opioids provide value for the management of acute musculoskeletal pain. However, prolong opioid use is associated with well-known consequences in the United States such as dependence, abuse and/or misuse. Considering these concerns and the effectiveness of non-pharmacological interventions for the treatment of acute pain, it is critical to identify the prescribing patterns for patients diagnosed with an ankle fracture in the ED. Objective: Describe the percentage of patients prescribed a scheduled and non-controlled medication in the ED. Methods: This was a secondary analysis of the publicly available data collected through the National Hospital Ambulatory Medical Care Survey from 2006-2015. Data analyzed using the sampled visit weight, yielding an unbiased national estimate of ED percentages. Due to the complex sample design, sampling errors were determined using SAS software. Results: From 2006-2015, 86.9% of patients presenting with an ankle fracture received medication during their ED visit. Among those prescribed a medication, 63.02% were prescribed a controlled substance and 34.29% were prescribed a non-controlled substance. The majority of the controlled substances were given to patients between the ages of 25-64. Conclusion: Approximately 2 out of 3 patients diagnosed with an ankle fracture in the ED received a controlled substance. The majority of these given to young-adults. Other effective non-pharmacological interventions should be explored to prevent the risk of the well-known consequences associated with opioid use. Word Count: 25

What Have We Learnt from Quantitative Case Reports of Acute Lateral Ankle Sprains Injuries and Episodes of \u27Giving-Way\u27 of the Ankle Joint, and What Shall We Further Investigate?

Lateral ankle sprains are a commonly incurred injury in sports. They have a high recurrence rate and can lead to the development of persistent injury associated symptoms. We performed a quantitative synthesis of published case reports documenting the kinematics of acute lateral ankle sprains and episodes of ‘giving-way’ of the ankle joint to provide a comprehensive description of the mechanisms. A systematic literature search was conducted to screen records within MEDLINE® and EMBASE®. Additional strategies included manual search of specific journals, as well as contacting researchers in relevant communities to retrieve unpublished data. Twenty-four cases were included in the quantitative synthesis, 11 from individual case reports and 13 from four separate case series. Two authors independently reviewed all the articles and extracted ankle joint kinematic data. Excessive ankle inversion was the most pronounced kinematic pattern observed across all included cases, with a mean peak inversion angle of 67.5° (range 2.0 to 142) and a mean peak inversion velocity of 974°/s (range 468 to 1752). This was followed by internal rotation and plantar flexion, respectively. A homogeneous linear function revealed a mean inversion velocity across all cases of 337°/s (range 117 to 1400; R2 = 0.78; p \u3c 0.0001)

Isometric Hip Strength and Dynamic Stability of Individuals With Chronic Ankle Instability

Context: Compared with individuals who have a history of lateral ankle sprain (LAS) without markers of chronic ankle instability (CAI; LAS copers) and healthy people, those with CAI often exhibit neuromuscular impairments and dynamic-stability deficits at the hip. However, the influence of hip-strength deficits on dynamic stability remains unknown. Objective: To compare isometric hip strength and dynamic stability in individuals with or without CAI and examine the degree of dynamic-stability variance explained by isometric hip strength. Design: Case-control study. Setting: Research laboratory. Patients or other participants: Sixty individuals (47 women, 13 men; age = 23.7 ± 4.6 years, height = 166.6 ± 7.7 cm, mass = 70.8 ± 15.7 kg) separated into CAI, LAS coper, and control groups based on previously established criteria. Main outcome measure(s): Group differences in resultant vector time to stabilization (RVTTS) and isometric hip-extension, -abduction, and external-rotation strength were determined using 1-way analyses of covariance that controlled for sex and limb (dominant or nondominant) tested and Cohen d effect sizes (95% confidence intervals). Backward linear regressions and Cohen f2 effect sizes (95% confidence intervals) determined the amount of RVTTS variance explained by isometric hip strength. Significance was set a priori at P \u3c .05. Results: The CAI group had less isometric hip-extension strength than LAS copers ( P = .02, d = 0.72 [0.06, 1.34]) and controls ( P = .01, d = 1.19 [0.50, 1.84]) and less external-rotation strength than LAS copers ( P = .03, d = 0.78 [0.13, 1.41]) and controls ( P = .01, d = 1.02 [0.34, 1.65]). No group differences existed for RVTTS ( F2,57 = 1.16, P = .32) or abduction strength ( F2,57 = 2.84, P = .07). Resultant vector time to stabilization was explained by isometric hip strength for LAS copers ( R2 = 0.21, f2 = 0.27 [0.22, 0.32], P = .04) but not for the CAI ( R2= 0.12, f2 = 0.14 [0.06, 0.22], P = .22) or control ( R2 = 0.10, f2 = 0.11 [0.03, 0.19], P = .18) groups. Conclusions: Participants with CAI had decreased isometric hip strength, but that did not equate to dynamic-stability deficits. Clinicians should include hip-muscle strengthening in rehabilitation protocols for patients with CAI, yet these gains may not enhance dynamic stability when landing from a jump

Isometric Hip Strength and Dynamic Stability of Individuals With Chronic Ankle Instability

Context: Compared with individuals who have a history of lateral ankle sprain (LAS) without markers of chronic ankle instability (CAI; LAS copers) and healthy people, those with CAI often exhibit neuromuscular impairments and dynamic-stability deficits at the hip. However, the influence of hip-strength deficits on dynamic stability remains unknown. Objective: To compare isometric hip strength and dynamic stability in individuals with or without CAI and examine the degree of dynamic-stability variance explained by isometric hip strength. Design: Case-control study. Setting: Research laboratory. Patients or other participants: Sixty individuals (47 women, 13 men; age = 23.7 ± 4.6 years, height = 166.6 ± 7.7 cm, mass = 70.8 ± 15.7 kg) separated into CAI, LAS coper, and control groups based on previously established criteria. Main outcome measure(s): Group differences in resultant vector time to stabilization (RVTTS) and isometric hip-extension, -abduction, and external-rotation strength were determined using 1-way analyses of covariance that controlled for sex and limb (dominant or nondominant) tested and Cohen d effect sizes (95% confidence intervals). Backward linear regressions and Cohen f2 effect sizes (95% confidence intervals) determined the amount of RVTTS variance explained by isometric hip strength. Significance was set a priori at P \u3c .05. Results: The CAI group had less isometric hip-extension strength than LAS copers ( P = .02, d = 0.72 [0.06, 1.34]) and controls ( P = .01, d = 1.19 [0.50, 1.84]) and less external-rotation strength than LAS copers ( P = .03, d = 0.78 [0.13, 1.41]) and controls ( P = .01, d = 1.02 [0.34, 1.65]). No group differences existed for RVTTS ( F2,57 = 1.16, P = .32) or abduction strength ( F2,57 = 2.84, P = .07). Resultant vector time to stabilization was explained by isometric hip strength for LAS copers ( R2 = 0.21, f2 = 0.27 [0.22, 0.32], P = .04) but not for the CAI ( R2= 0.12, f2 = 0.14 [0.06, 0.22], P = .22) or control ( R2 = 0.10, f2 = 0.11 [0.03, 0.19], P = .18) groups. Conclusions: Participants with CAI had decreased isometric hip strength, but that did not equate to dynamic-stability deficits. Clinicians should include hip-muscle strengthening in rehabilitation protocols for patients with CAI, yet these gains may not enhance dynamic stability when landing from a jump

Hip Strength and Star Excursion Balance Test Deficits of Patients With Chronic Ankle Instability

Objectives: To examine isometric hip strength in those with and without CAI, and determine the degree of Star Excursion Balance Test (SEBT) variance explained by isometric hip strength. Design: Single-blinded, cross-sectional, case-control study. Methods: Thirty individuals with CAI, 29 lateral ankle sprain (LAS) copers, and 26 healthy controls participated. We assessed dynamic postural control with the SEBT anterior (SEBT-ANT), posteromedial (SEBT-PM), and posterolateral (SEBT-PL) reaches, and isometric hip extension (EXT), abduction (ABD) and external rotation (ER) strength with hand-held dynamometry. The CAI and LAS coper groups\u27 involved limbs and randomly selected limbs in controls were tested. Separate Kruskal-Wallis tests compared SEBT scores and isometric hip strength between groups. Backwards linear regression models determined the degree of SEBT variance explained by isometric hip strength. Statistical significance was set a priori at P\u3c0.05. Results: The CAI group had lower SEBT-ANT scores compared to LAS copers (P=0.03) and controls (P=0.03). The CAI group had lower ABD compared to LAS copers (P=0.03) and controls (P=0.02). The CAI group had lower ER compared to LAS copers (P=0.01) and controls (P=0.01). ER (R2=0.25, P=0.01) and ABD (R2=0.25, P=0.01) explained 25% of the CAI group\u27s SEBT-PM and SEBT-PL variances, respectively. Conclusions: The CAI group had lower SEBT-ANT scores compared to LAS copers (P=0.03) and controls (P=0.03). The CAI group had lower ABD compared to LAS copers (P=0.03) and controls (P=0.02). The CAI group had lower ER compared to LAS copers (P=0.01) and controls (P=0.01). ER (R2=0.25, P=0.01) and ABD (R2=0.25, P=0.01) explained 25% of the CAI group\u27s SEBT-PM and SEBT-PL variances, respectively. Conclusions: The CAI group had deficient dynamic postural control and isometric hip strength compared to LAS copers and controls. Additionally, the CAI group\u27s isometric hip strength significantly influenced dynamic postural control performance. Future CAI rehabilitation strategies should consider hip muscular strengthening to facilitate improvements in dynamic postural control

What have we learnt from quantitative case reports of acute lateral ankle sprains injuries and episodes of ‘giving-way’ of the ankle joint, and what shall we further investigate?

Lateral ankle sprains are a commonly incurred injury in sports. They have a high recurrence rate and can lead to the development of persistent injury associated symptoms. We performed a quantitative synthesis of published case reports documenting the kinematics of acute lateral ankle sprains and episodes of ‘giving-way’ of the ankle joint to provide a comprehensive description of the mechanisms. A systematic literature search was conducted to screen records within MEDLINE® and EMBASE®. Additional strategies included manual search of specific journals, as well as contacting researchers in relevant communities to retrieve unpublished data. Twenty-four cases were included in the quantitative synthesis, 11 from individual case reports and 13 from four separate case series. Two authors independently reviewed all the articles and extracted ankle joint kinematic data. Excessive ankle inversion was the most pronounced kinematic pattern observed across all included cases, with a mean peak inversion angle of 67.5° (range 2.0 to 142) and a mean peak inversion velocity of 974°/s (range 468 to 1752). This was followed by internal rotation and plantar flexion, respectively. A homogeneous linear function revealed a mean inversion velocity across all cases of 337°/s (range 117 to 1400; R2 = 0.78; p < 0.0001)