Luke Donovan

A New Paradigm for Rehabilitation of Patients with Chronic Ankle Instability

Abstract Lateral ankle sprains have been shown to be one of the most common musculoskeletal injuries in both athletes and the recreationally active population. Moreover, it is estimated that approximately 30% of people who incur a lateral ankle sprain will ssustain recurrent ankle sprains and experience symptoms of pain and instability that last > 1 year. Chronic ankle instability (CAI) is the term used to describe cases involving repetitive ankle sprains, multiple episodes of the ankle “giving way,“ persistent symptoms, and diminished self-reported function for > 1 year after the initial ankle sprain. The optimal conservative treatment for CAI is yet to be determined; however, comparison between patients with CAI and individuals showing no history of ankle sprain has revealed several characteristic features of CAI. These include diminished range of motion, decreased strength, impaired neuromuscular control, and altered functional movement patterns. We propose a new treatment paradigm for conservative management of CAI with the aim of assessing and treating specific deficits exhibited by individual patients with CAI.

Lower Extremity Muscle Activation in Patients With or Without Chronic Ankle Instability During Walking

CONTEXT Ankle sprains are among the most common musculoskeletal injuries, and many individuals with ankle sprains develop chronic ankle instability (CAI). Individuals with CAI exhibit proprioceptive and postural-control deficits, as well as altered osteokinematics, during gait. Neuromuscular activity is theorized to play a pivotal role in CAI, but deficits during walking are unclear. OBJECTIVE To compare motor-recruitment patterns as demonstrated by surface electromyography amplitudes between participants with CAI and healthy control participants during walking. DESIGN Descriptive laboratory study. SETTING Laboratory. PATIENTS OR OTHER PARTICIPANTS Fifteen adults with CAI (5 men, 10 women; age = 23 ± 4.2 years, height = 173 ± 10.8 cm, mass = 72.4 ± 14 kg) and 15 matched healthy control adults (5 men, 10 women; age = 22.9 ± 3.4 years, height = 173 ± 9.4 cm, mass = 70.8 ± 18 kg). INTERVENTION(S) Participants walked shod on a treadmill while surface electromyography signals were recorded from the anterior tibialis, peroneus longus, lateral gastrocnemius, rectus femoris, biceps femoris, and gluteus medius muscles. MAIN OUTCOME MEASURE(S) Preinitial contact amplitude, postinitial contact amplitude, time of activation relative to initial contact, and percentage of activation time across the stride cycle were calculated for each muscle. RESULTS Time of activation for all muscles tested occurred earlier in the CAI group than in the control group. The peroneus longus was activated for a longer duration across the entire stride cycle in the CAI group (36.0% ± 10.3%) than the control group (23.3% ± 22.2%; P = .05). No differences were noted between groups for measures of electromyographic amplitude at either preinitial or postinitial contact (P > .05). CONCLUSIONS We identified differences between the CAI and control groups in the timing of muscle activation relative to heel strike in multiple lower extremity muscles and in the percentage of activation time across the entire stride cycle in the peroneus longus muscle. Individuals with CAI demonstrated neuromuscular-activation strategies throughout the lower extremity that were different from those of healthy control participants. Targeted therapeutic interventions for CAI may need to be focused on restoring normal neuromuscular function during gait.

Lower Extremity Muscle Activation During Functional Exercises in Patients With and Without Chronic Ankle Instability

To determine whether individuals with chronic ankle instability (CAI) exhibit altered neuromuscular control as demonstrated by surface electromyography (EMG) amplitudes compared with healthy controls during single‐limb eyes‐closed balance, Star Excursion Balance Test, forward lunge, and lateral hop exercises.

Rehabilitation for Chronic Ankle Instability With or Without Destabilization Devices: A Randomized Controlled Trial

CONTEXT Individuals with chronic ankle instability (CAI) have deficits in neuromuscular control and altered movement patterns. Ankle-destabilization devices have been shown to increase lower extremity muscle activity during functional tasks and may be useful tools for improving common deficits and self-reported function. OBJECTIVE To determine whether a 4-week rehabilitation program that includes destabilization devices has greater effects on self-reported function, range of motion (ROM), strength, and balance than rehabilitation without devices in patients with CAI. DESIGN Randomized controlled clinical trial. SETTING Laboratory. PATIENTS OR OTHER PARTICIPANTS A total of 26 patients with CAI (7 men, 19 women; age = 21.34 ± 3.06 years, height = 168.96 ± 8.77 cm, mass = 70.73 ± 13.86 kg). INTERVENTION(S) Patients completed baseline measures and were randomized into no-device and device groups. Both groups completed 4 weeks of supervised, impairment-based progressive rehabilitation with or without devices and then repeated baseline measures. MAIN OUTCOME MEASURE(S) We assessed self-reported function using the Foot and Ankle Ability Measure. Ankle ROM was measured with an inclinometer. Ankle strength was assessed using a handheld dynamometer during maximal voluntary isometric contractions. Balance was measured using a composite score of 3 reach directions from the Star Excursion Balance Test and a force plate to calculate center of pressure during eyes-open and eyes-closed single-limb balance. We compared each dependent variable using a 2 × 2 (group × time) analysis of variance and post hoc tests as appropriate and set an a priori α level at .05. The Hedges g effect sizes and associated 95% confidence intervals were calculated. RESULTS We observed no differences between the no-device and device groups for any measure. However, both groups had large improvements in self-reported function and ankle strength. CONCLUSIONS Incorporating destabilization devices into rehabilitation did not improve ankle function more effectively than traditional rehabilitation tools because both interventions resulted in similar improvements. Impairment-based progressive rehabilitation improved clinical outcomes associated with CAI.

Current Trends in the Management of Lateral Ankle Sprain in the United States

Objective: To characterize trends in the acute management (within 30 days) after lateral ankle sprain (LAS) in the United States. Design: Descriptive epidemiology study. Patients: Of note, 825 718 ankle sprain patients were identified; 96.2% were patients with LAS. Seven percent had an associated fracture and were excluded from the remaining analysis. Setting: Primary and tertiary care settings. Interventions: We queried a database of national health insurance records for 2007 to 2011 by ICD-9 codes for patients with LAS while excluding medial and syndesmotic sprains and any LAS with an associated foot or ankle fracture. Main Outcome Measures: The percentage of patients to receive specific diagnostic imaging, orthopedic devices, or physical therapy treatments within 30 days of the LAS diagnosis and the associated costs. Results: Over two-thirds of patients with LAS without an associated fracture received radiographs, 9% received an ankle brace, 8.1% received a walking boot, 6.5% were splinted, and 4.8% were prescribed crutches. Only 6.8% received physical therapy within 30 days of their LAS diagnosis, 94.1% of which performed therapeutic exercise, 52.3% received manual therapy, and 50.2% received modalities. The annual cost associated with physician visits, diagnostic imaging, orthopedic devices, and physical therapy was 152 million USD, 81.5% was from physician evaluations, 7.9% from physical therapy, 7.2% from diagnostic imaging, and 3.4% from orthopedic devices. Conclusions: Most patients with LAS do not receive supervised rehabilitation. The small proportion of patients with LAS to receive physical therapy get rehabilitation prescribed in accordance with clinical practice guidelines. The majority (>80%) of the LAS financial burden is associated with physician evaluations.

Effect of lace-up ankle braces on electromyography measures during walking in adults with chronic ankle instability.

BACKGROUND Lace-up ankle braces reduce the incidence of ankle sprains and have been hypothesized to do so through both mechanical and neuromuscular mechanisms. OBJECTIVE To determine the effect of lace-up ankle braces on surface electromyography (sEMG) measures during walking in adults with chronic ankle instability (CAI). DESIGN Randomized crossover. SETTING Laboratory. PARTICIPANTS Fifteen adults with CAI. MAIN OUTCOME MEASURES Surface EMG activity was recorded from the anterior tibialis, peroneus longus, lateral gastrocnemius, rectus femoris, biceps femoris and gluteus medius during treadmill walking with and without lace-up ankle braces. The dependent variables were sEMG amplitude 100 ms pre- and 200 ms post-initial contact, time of activation relative to initial contact, and percent of activation across the stride cycle. RESULTS When compared to no brace, ankle bracing resulted in lower pre-contact amplitude of the peroneus longus (p = 0.02). The anterior tibialis, peroneus longus, rectus femoris, and gluteus medius were activated later relative to initial contact (p < 0.03). The peroneus longus and rectus femoris were activated for a shorter percentage of the stride cycle (p < 0.05). CONCLUSION Braces cause a change in neuromuscular activity during walking. Clinicians should be aware of these changes when prescribing braces, as it may relate to the mechanism in which braces decrease sprains.

Effects of 2 Ankle Destabilization Devices on Electromyography Measures During Functional Exercises in Individuals With Chronic Ankle Instability

STUDY DESIGN Randomized crossover laboratory study. OBJECTIVES To determine the effects of ankle destabilization devices on surface electromyography (sEMG) measures of selected lower extremity muscles during functional exercises in participants with chronic ankle instability. BACKGROUND Ankle destabilization devices are rehabilitation tools that can be worn as a boot or sandal to increase lower extremity muscle activation during walking in healthy individuals. However, they have not been tested in a population with pathology. METHODS Fifteen adults with chronic ankle instability participated. Surface electromyography electrodes were located over the anterior tibialis, fibularis longus, lateral gastrocnemius, rectus femoris, biceps femoris, and gluteus medius. The activity level of these muscles was recorded in a single testing session during unipedal stance with eyes closed, the Star Excursion Balance Test, lateral hops, and treadmill walking. Each task was performed under 3 conditions: shod, ankle destabilization boot, and ankle destabilization sandal. Surface electromyography signal amplitudes were measured for each muscle during each exercise for all 3 conditions. RESULTS Participants demonstrated a significant increase, with moderate to large effect sizes, in sEMG signal amplitude of the fibularis longus in the ankle destabilization boot and ankle destabilization sandal conditions during the unipedal eyes-closed balance test, the Star Excursion Balance Test in the anterior and posteromedial directions, lateral hops, and walking, when compared to the shod condition. Both devices also resulted in an increase in sEMG signal amplitudes, with large effect sizes of the lateral gastrocnemius, rectus femoris, biceps femoris, and gluteus medius during the unipedal-stance-with-eyes-closed test, compared to the shod condition. CONCLUSION Wearing ankle destabilization devices caused greater muscle activation during functional exercises in individuals with chronic ankle instability. Based on the magnitude of the effect, there were consistent increases in fibularis longus sEMG amplitudes during the unipedal eyes-closed balance test, the Star Excursion Balance Test in the anterior and posteromedial directions, and pre-initial contact and post-initial contact during lateral hops and walking.

Effects of ankle destabilization devices and rehabilitation on gait biomechanics in chronic ankle instability patients: A randomized controlled trial

UNLABELLED Patients with chronic ankle instability (CAI) have altered gait patterns, which are characterized by increased inversion positioning during gait. Ankle destabilization devices increase peroneus longus muscle activation during gait, which may increase eversion. OBJECTIVE To determine whether incorporating destabilization devices into a 4-week impairment-based rehabilitation program has beneficial effects on gait biomechanics and surface electromyography (sEMG) compared to impairment-based rehabilitation without destabilization devices in CAI patients. DESIGN Randomized controlled trial. SETTING Laboratory. PARTICIPANTS Twenty-six CAI patients. OUTCOME MEASURES Patients completed baseline gait trials and were randomized into no device or device groups. Groups completed 4-weeks of rehabilitation with or without devices, and then completed post-intervention gait trials. Lower extremity sagittal and frontal plane kinematics and kinetics and sEMG activity were measured. RESULTS The device group increased dorsiflexion during mid-late stance and had lower normalized sEMG amplitude for the peroneus longus during early stance and mid-swing after rehabilitation. The no device group had less peroneus brevis sEMG activity during early stance after rehabilitation. CONCLUSION Incorporating destabilization devices in a 4-week rehabilitation program was an effective method of improving dorsiflexion during the stance phase of gait. However, impairment-based rehabilitation, regardless of instability tool, was not effective at improving frontal plane motion.

Effects of an auditory biofeedback device on plantar pressure in patients with chronic ankle instability

Chronic ankle instability (CAI) patients have been shown to have increased lateral column plantar pressure throughout the stance phase of gait. To date, traditional CAI rehabilitation programs have been unable to alter gait. We developed an auditory biofeedback device that can be worn in shoes that elicits an audible cue when an excessive amount of pressure is applied to a sensor. This study determined whether using this device can decrease lateral plantar pressure in participants with CAI and alter surface electromyography (sEMG) amplitudes (anterior tibialis, peroneus longus, medial gastrocnemius, and gluteus medius). Ten CAI patients completed baseline treadmill walking while in-shoe plantar pressures and sEMG were measured (baseline condition). Next, the device was placed into the shoe and set to a threshold that would elicit an audible cue during each step of the participants normal gait. Then, participants were instructed to walk in a manner that would not trigger the audible cue, while plantar pressure and sEMG measures were recorded (auditory feedback (AUD FB) condition). Compared to baseline, there was a statistically significant reduction in peak pressure in the lateral midfoot-forefoot and central forefoot during the AUD FB condition. In addition, there were increases in peroneus longus and medial gastrocnemius sEMG amplitudes 200 ms post-initial contact during the AUD FB condition. The use of this auditory biofeedback device resulted in decreased plantar pressure in the lateral column of the foot during treadmill walking in CAI patients and may have been caused by the increase in sEMG activation of the peroneus longus.

Eversion Strength and Surface Electromyography Measures With and Without Chronic Ankle Instability Measured in 2 Positions

Background: Individuals with chronic ankle instability (CAI) have demonstrated strength deficits compared to healthy controls; however, the influence of ankle position on force measures and surface electromyography (sEMG) activation of the peroneus longus and brevis has not been investigated. The purpose of this study was to compare sEMG amplitudes of the peroneus longus and brevis and eversion force measures in 2 testing positions, neutral and plantarflexion, in groups with and without CAI. Methods: Twenty-eight adults (19 females, 9 males) with CAI and 28 healthy controls (19 females, 9 males) participated. Hand-held dynamometer force measures were assessed during isometric eversion contractions in 2 testing positions (neutral, plantarflexion) while surface sEMG amplitudes of the peroneal muscles were recorded. Force measures were normalized to body mass, and sEMG amplitudes were normalized to a resting period. Results: The group with CAI demonstrated less force when compared to the control group (P < .001) in both the neutral and plantarflexion positions: neutral position, CAI: 1.64 Nm/kg and control: 2.10 Nm/kg) and plantarflexion position, CAI: 1.40 Nm/kg and control: 1.73 Nm/kg). There were no differences in sEMG amplitudes between the groups or muscles (P > .05). Force measures correlated with both muscles’ sEMG amplitudes in the healthy group (neutral peroneus longus: r = 0.42, P = .03; plantarflexion peroneus longus: r = 0.56, P = .002; neutral peroneus brevis: r = 0.38, P = .05; plantarflexion peroneus longus: r = 0.40, P = .04), but not in the group with CAI (P > .05). Conclusions: The group with CAI generated less force when compared to the control group during both testing positions. There was no selective activation of the peroneal muscles with testing in both positions, and force output and sEMG activity was only related in the healthy group. Clinical relevance: Clinicians should assess eversion strength and implement strength training exercises in different sagittal plane positions and evaluate for other pathologies that may contribute to reduced eversion strength in patients with CAI. Level of Evidence: Level III, cross-sectional