Mark A. Feger

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.

Supervised Rehabilitation Versus Home Exercise in the Treatment of Acute Ankle Sprains: A Systematic Review

In competitive sports medicine, supervised rehabilitation is the standard of care; in the general population, unsupervised home exercise is more common. We systematically reviewed randomized, controlled trials comparing outcomes for supervised rehabilitation versus home exercise programs. Supervised rehabilitation programs resulted in (1) less pain and subjective instability, (2) greater gains in ankle strength and joint position sense, and (3) inconclusive results regarding prevention of recurrent ankle sprains. We recommend supervised rehabilitation over home exercise programs owing to the improved short-term patient-recorded evidence with a strength-of-recommendation taxonomy level of evidence of 2B.

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.

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.

Effect of Surgical Approach on Pulmonary Function in Adolescent Idiopathic Scoliosis Patients: A Systemic Review and Meta-analysis.

Study Design. Systemic review and meta-analysis. Objective. To analyze the effect of spinal fusion and instrumentation for adolescent idiopathic scoliosis (AIS) on absolute pulmonary function test (PFTs). Summary of Background Data. Pulmonary function is correlated with severity of deformity in AIS patients and studies that have analyzed the effect of spinal fusion and instrumentation on PFTs for AIS have reported inconsistent results. There is a need to analyze the effect of spinal fusion on PFTs with stratification by surgical approach. Methods. Our analysis included 22 studies. Cohens d effect sizes were calculated for absolute PFT outcome measures with 95% confidence intervals (CI). Meta-analyses were performed at each postoperative time frame for six homogeneous surgical approaches: (i) combined anterior release and posterior fusion with instrumentation; (ii) combined video assisted anterior release and posterior fusion with instrumentation without thoracoplasty; (iii) posterior fusion with instrumentation without thoracoplasty; (iv) anterior fusion with instrumentation and without thoracoplasty; (v) video assisted anterior fusion with instrumentation without thoracoplasty; and (vi) any scoliosis surgery with additional thoracoplasty. Results. Anterior spinal fusion with instrumentation, any scoliosis surgery with concomitant thoracoplasty, or video-assisted anterior fusion with instrumentation for AIS had similar absolute PFTs at their 2 year postoperative follow up compared with their preoperative PFTs (effect sizes ranging from −0.2–0.2 with all CI crossing “0”). Posterior spinal fusion with instrumentation (with or without an anterior release) demonstrated small to moderate increases in PFTs 2 years postoperatively (effect sizes ranging from 0.35–0.65 with all CI not crossing “0”). Conclusion. Anterior fusion with instrumentation, regardless of the approach, and any scoliosis surgery with concomitant thoracoplasty do not lead to significant change in pulmonary functions 2 year after surgery. Posterior spinal fusion with instrumentation (with or without an anterior release) resulted in small to moderate increases in PFTs. Level of Evidence: N/A

Diminished Foot and Ankle Muscle Volumes in Young Adults With Chronic Ankle Instability

Background: Patients with chronic ankle instability (CAI) have demonstrated altered neuromuscular function and decreased muscle strength when compared with healthy counterparts without a history of ankle sprain. Up to this point, muscle volumes have not been analyzed in patients with CAI to determine whether deficits in muscle size are present following recurrent sprain. Purpose: To analyze intrinsic and extrinsic foot and ankle muscle volumes and 4-way ankle strength in young adults with and without CAI. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Five patients with CAI (mean age, 23.0 ± 4 years; 1 male, 4 females) and 5 healthy controls (mean age, 23.8 ± 4.5 years; 1 male, 4 females) volunteered for this study. Novel fast-acquisition magnetic resonance imaging (MRI) was used to scan from above the femoral condyles through the foot and ankle. The perimeter of each muscle was outlined on each axial slice and then the 2-dimensional area was multiplied by the slice thickness (5 mm) to calculate the muscle volume. Plantar flexion, dorsiflexion, inversion, and eversion isometric strength were measured using a handheld dynamometer. Patients with CAI were compared with healthy controls on all measures of muscle volume and strength. Extrinsic muscle volumes of patients with CAI were also compared with a normative database of healthy controls (n = 24) by calculating z scores for each muscle individually for each CAI subject. Results: The CAI group had smaller total shank, superficial posterior compartment, soleus, adductor hallucis obliqus, and flexor hallucis brevis muscle volumes compared with healthy controls as indicated by group means and associated 90% CIs that did not overlap. Cohen d effect sizes for the significant group differences were all large and ranged from 1.46 to 3.52, with 90% CIs that did not cross zero. The CAI group had lower eversion, dorsiflexion, and 4-way composite ankle strength, all with group means and associated 90% CIs that did not overlap. No other significant differences were identified. Conclusion: Patients with CAI demonstrate atrophy of intrinsic and extrinsic foot and ankle musculature accompanied by lower ankle strength. Clinical Relevance: Clinicians should be aware of the muscle atrophy and strength deficits when prescribing rehabilitation for patients with lateral ankle sprain or CAI.

Comparative Effects of Multilevel Muscle Tendon Surgery, Osteotomies, and Dorsal Rhizotomy on Functional and Gait Outcome Measures for Children With Cerebral Palsy

To compare the impact of common surgical interventions (selective dorsal rhizotomy, muscle‐tendon surgery, and osteotomies) for patients with cerebral palsy (CP) on Gross Motor Function Measure and temporal, kinematic, and kinetic gait variables as assessed via 3‐dimensional motion analysis.