Muscle-Activation Onset Times With Shoes and Foot Orthoses in Participants With Chronic Ankle Instability

Context

Participants with chronic ankle instability (CAI) use an altered neuromuscular strategy to shift weight from double-legged to single-legged stance. Shoes and foot orthoses may influence these muscle-activation patterns.

Objective

To evaluate the influence of shoes and foot orthoses on onset times of lower extremity muscle activity in participants with CAI during the transition from double-legged to single-legged stance.

Design

Cross-sectional study.

Setting

Musculoskeletal laboratory.

Patients or Other Participants

A total of 15 people (9 men, 6 women; age = 21.8 ± 3.0 years, height = 177.7 ± 9.6 cm, mass = 72.0 ± 14.6 kg) who had CAI and wore foot orthoses were recruited.

Intervention(s)

A transition task from double-legged to single-legged stance was performed with eyes open and with eyes closed. Both limbs were tested in 4 experimental conditions: (1) barefoot (BF), (2) shoes only, (3) shoes with standard foot orthoses, and (4) shoes with custom foot orthoses (SCFO).

Main Outcome Measure(s)

The onset of activity of 9 lower extremity muscles was recorded using surface electromyography and a single force plate.

Results

Based on a full-factorial (condition, region, limb, vision) linear model for repeated measures, we found a condition effect (F_3,91.8 = 9.39, P < .001). Differences among experimental conditions did not depend on limb or vision condition. Based on a 2-way (condition, muscle) linear model within each region (ankle, knee, hip), earlier muscle-activation onset times were observed in the SCFO than in the BF condition for the peroneus longus (P < .001), tibialis anterior (P = .003), vastus medialis obliquus (P = .04), and vastus lateralis (P = .005). Furthermore, the peroneus longus was activated earlier in the shoes-only (P = .02) and shoes-with-standard-foot-orthoses (P = .03) conditions than in the BF condition. No differences were observed for the hip muscles.

Conclusions

Earlier onset of muscle activity was most apparent in the SCFO condition for ankle and knee muscles but not for hip muscles during the transition from double-legged to single-legged stance. These findings might help clinicians understand how shoes and foot orthoses can influence neuromuscular control in participants with CAI.Key Words: footwear, insoles, ankle sprains, neuromuscular system, electromyography

Key Points

• Shoes and foot orthoses accelerated muscle-activation onset times of the ankle and knee but not the hip in participants with chronic ankle instability.
• Earlier muscle-activation onset times were most prominent in the shoes-with-custom-foot-orthoses condition.
• At the ankle, the muscle-activation onset time of the peroneus longus was earlier in the shoes-only, shoes-with-standard-foot-orthoses, and shoes-with-custom-foot-orthoses conditions than in the barefoot condition, and the muscle-activation onset time of the tibialis anterior was earlier in the shoes-with-custom-foot-orthoses condition than in the barefoot condition.
• At the knee, the muscle-activation onset times of the vastus medialis obliquus and vastus lateralis were earlier in the shoes-with-custom-foot-orthoses condition than in the barefoot condition.
• The results may help clinicians understand how shoes and foot orthoses can influence neuromuscular control of the lower extremity in participants with chronic ankle instability.

Lateral ankle sprains are estimated to account for approximately 15% of all sport injuries.¹ Even more concerning than the initial ankle sprain is the large proportion of patients with residual symptoms and recurrent ankle sprains for months to years after the initial injury.² The occurrence of repetitive ankle sprains and the feeling of the ankle “giving way” with slight or no perturbation has been defined as chronic ankle instability (CAI).³The transition task from double-legged to single-legged stance during barefoot (BF) conditions has been shown to discriminate between uninjured participants and participants with CAI. Researchers have reported that muscle-activation onset times typically were delayed^4,5 and postural stability was impaired⁶ in participants with CAI, indicating the use of another strategy to shift weight from double-legged to single-legged stance. However, it is unclear whether findings from BF tests represent typical daily situations when shoes, and for some persons foot orthoses, are often worn.The human foot is the first point of contact between the body and a supporting surface. The cutaneous mechanoreceptors on the planar surface of the foot are an important source of sensory information,⁷ which is considered essential for achieving and maintaining functional joint stability.⁸ Shoes and foot orthoses act as an interface between the body and a supporting surface and can influence the sensory feedback from these mechanoreceptors by increasing the contact area between the foot and the supporting surface.^7,9 Furthermore, the small kinematic alterations of the rear foot and tibia that have been described with the use of shoes and foot orthoses¹⁰ may put the ankle joint in a more neutral position, thereby improving the capacity of the ankle mechanoreceptors to provide more accurate proprioceptive input toward the central nervous system.¹¹ Changing the sensory input to these mechanisms consequently would change the motor output.⁷Evidence is increasing that shoes and foot orthoses can influence lower extremity muscle activation.^10,12–14 Dingenen et al¹⁴ were the first investigators to measure the influence of shoes and foot orthoses on muscle-activation onset times of the entire lower extremity in uninjured participants during the transition from double-legged to single-legged stance. Their results showed that shoes and foot orthoses can accelerate muscle-activation onset times of the peroneus longus. No differences were reported in more proximal muscles. Recently, researchers have suggested that future investigators should be focused on the influence of shoes and foot orthoses on neuromuscular control, especially in participants with injuries, such as CAI,^10,13,14 to increase our understanding of how positive clinical outcomes from the use of shoes and foot orthoses can be achieved.¹¹ Altering or improving proprioceptive information and muscle-activation patterns in participants with CAI would be clinically beneficial, given that their proprioceptive and neuromuscular deficits have been described.¹⁵To our knowledge, no investigators have focused on the influence of shoes and foot orthoses on muscle-activation onset times of the entire lower extremity in participants with CAI during the transition from double-legged to single-legged stance. Therefore, the purpose of our study was to evaluate the influence of shoes and foot orthoses on muscle-activation onset times during the transition from double-legged to single-legged stance in participants with CAI. Based on the proposed effects of shoes and foot orthoses on lower extremity neuromuscular control, we hypothesized that shoes and foot orthoses would accelerate muscle-activation onset times compared with a BF condition.     

PROPHYLACTIC VS. SYMPTOMATIC THIRD MOLAR REMOVAL: EFFECTS ON PATIENT POSTOPERATIVE MORBIDITY

PurposeThe present study aimed to assess differences in postoperative morbidity between prophylactic and symptomatic third molar removals, and to assess the effect of age on the recovery of the patient.MethodsPatients admitted for third molar removal were prospectively followed up four times during treatment in context of the M3BE study. Data were collected through pre-, peri and postoperative surveys (days 3 and 10). Uni- and multivariable logistic regression was used to assess the probability of postoperative symptoms of discomfort on day 3 and day 10 according to several patient- and surgery-related predictive factors (age, gender, indication for removal, method of extraction, anesthesia and number of extracted maxillary and/or mandibular third molars).ResultsIn total, 6010 patients with a mean age of 25.2 (± 11.2) underwent 6347 surgeries to have 15,357 third molars removed. Frequently observed symptoms of postoperative discomfort were pain, trismus and swelling, all of which were transient in nature with steep decreases from postoperative days 3 to 10. Increasing age was associated with an enhanced risk of persistent pain, trismus and swelling and a significantly higher risk of iatrogenic injury to the inferior alveolar nerve. Symptomatic indications for removal were more common in patients over age 25 years, but these pre-existing pathologies did not compromise the postoperative recovery process. Other factors related to postoperative morbidity were female gender, intraoperative osteotomy and the number of extractions.ConclusionThe results of this study suggest that there are convincing patient- and surgery-related factors that favor timely third molar removal, preferably before the age of 25, especially in order to avoid persistent morbidity and nerve complications.     

Multi-modular bone healing assessment in a randomized controlled clinical trial of root-end surgery with the use of leukocyte- and platelet-rich fibrin and an occlusive membrane

Clinical Oral Investigations - The aim of this study was to assess in a multi-modular manner the bone healing 1&nbsp;year post root-end surgery (RES) with leukocyte- and platelet-rich fibrin...     

Recurrent Symptoms after Stapled Haemorrhoidopexy and the Impact on Patient Satisfaction after a Minimum of 2 Years Follow-up

Background : Stapled haemorrhoidopexy came as an attractive alternative to treat grade 3 haemorrhoids. This study aims to assess the nature of recurrent symptoms and the impact on patient satisfaction after a minimum follow-up of two years in a group of patients who underwent stapled haemorrhoidopexy.

Methods : A standardized questionnaire was used to evaluate a consecutive group of patients by telephone treated by a stapled haemorrhoidopexy between January 2004 and December 2007. Outcome assessment comprised residual symptoms, subsequent treatment, and patient satisfaction.

Results : Hundred sixty-five patients underwent a stapled haemorrhoidopexy in the study period. Twenty-five patients (15%) were lost to follow-up. The included 140 patients presented with grade 2 (16) or grade 3 (124) prolapsing internal haemorrhoids. Median age was 50 years (range 27–79) and 56% were males. Median follow-up was 43 months (range 25–87). At final follow-up, 79 patients (56%) remained symptom-free. Nevertheless, 89% were more than satisfied. Only 11% were disappointed with the ultimate outcome. Recurrent symptoms were prolapse (52 patients), anal bleeding (46 patients), anal pressure or pain (24 patients) and pruritus (21 patients). Thirty-five patients had subsequent therapy: 20 underwent surgical resection and 15 had sclerotherapy or rubber band ligation. Patient satisfaction correlates with the number of recurrent (residual) symptoms and the need for further treatment.

Conclusion : Despite the high symptomatic recurrence rate after stapled haemorrhoidopexy, 89% of patients were satisfied. This suggests that recurrent or residual symptoms after stapled haemorrhoidopexy are often less severe compared to the initial presenting symptoms.     

Dental age estimation in Somali children and sub-adults combining permanent teeth and third molar development

Estimation of an individual’s age has important applications in forensics. In young individuals, it often relies on separate evaluations of permanent teeth (PT) and third molars (TM) development. Here, we analysed the age prediction performance of combined information from PT and TM in an unusual sample of healthy Somalis, born and living in Finland. PT development was staged according to Demirjian et al. (Hum Biol, 1973) and TM development according to Köhler et al. (Ann Anat, 1994), using panoramic radiographs from 803 subjects (397 males, 406 females) aged 3–23 years. A sex-specific Bayesian age-estimation model for the multivariate distribution of the stages conditional on age was fitted on PT, TM and PT and TM combined. The age-estimation performances were validated and quantified. The approach combining PT and TM only overestimated age with an ME of − 0.031 years in males and − 0.011 years in females, indicating the best age prediction performance.

     

Evaluation of stair motion contributes to new insights into hip osteoarthritis‐related motion pathomechanics

Stair motion in the presence of hip osteoarthritis (OA) has received less attention than level walking. Its more strenuous aspect may shed the light on different locomotor strategies when compared to walking. We, therefore, aimed to define stair motion features associated to hip OA and to evaluate whether these specific features would differ from level walking and better characterize the hip pathological condition. Principal component and linear discriminant analyses were, respectively, used as data reduction and classification techniques. Our study highlighted that most of stair motion features associated to hip OA were similar to the ones of walking. Stair descent presented with the lowest misclassification error rate, ranging from 12% to 19% (estimated by cross‐validation). But, features that may be considered as a mechanism to reduce demand on the hip abductors were found to be more important in the stair ascent condition. This was reflected by both, greater importance in the classification rule and variance compared with walking, that is, decreased hip internal rotation moment at mid‐stance (72.50% vs. 57.63%) and increased trunk lateroflexion toward affected side (56.43% vs. 29.37%). This study emphasized the importance of investigating stair motion in hip osteoarthritic population by highlighting specific locomotor strategies. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:187–196, 2016.     

Correlation between ocular pulse amplitude measured by dynamic contour tonometer and visual field defects

Purpose To investigate the correlation between ocular pulse amplitude and visual field defects in patients with glaucoma, ocular hypertension, and glaucoma suspicion when measured with the Pascal Dynamic Contour Tonometer, and to verify if the ocular pulse amplitude is an independent predictor for visual field parameters. Methods Seventy-seven eyes (42 patients) with glaucoma, ocular hypertension or glaucoma suspicion were examined. Ocular pulse amplitude was measured with the dynamic contour tonometer by one investigator masked to the visual field data. Visual fields were performed within three months of ocular pulse amplitude measurement by the Octopus or Humphrey Field Analyser, and were analysed with Peridata Software. Mean defect, pattern standard deviation (√ Loss Variance) and regression analysis of those parameters (Trend Indices) were correlated with the ocular pulse amplitude for each eye. Results Forty-nine eyes had glaucoma, 14 had ocular hypertension, and 14 were glaucoma suspects. The mean follow-up was 46.5 (range 6–96) months. There was a significant correlation between OPA and MD and OPA and PSD, even after correction for IOP (and diagnostic group and eye): the estimated slope equals 2.68 (S.E. = 0.82, p = 0.003) and −0.86 (S.E. = 0.33, p = 0.014), respectively. There was even a weak correlation between OPA and the evolution of MD (dB/year). The slope estimate for OPA equals 0.070 (S.E. = 0.033), p = 0.037. However, after correction for IOP (and diagnostic group and eye), the strength of the relationship is reduced and the evidence disappears: the slope estimate for OPA now equals 0.039 (S.E. = 0.041), p = 0.34. There is no evidence for an association between OPA and the evolution of Trend-PSD. Conclusion A small ocular pulse amplitude, as measured with a dynamic contour tonometer, is correlated with moderate to severe glaucomatous visual field loss and might be a risk factor for the development of glaucomatous visual field defects.     

Comparison of effective doses for low-dose MDCT and radiographic examination of sinuses in children

OBJECTIVE: Our objective was to show that in low-dose MDCT of the sinuses in children the effective dose can be lowered to a level comparable to that used for standard radiographic images, with resultant CT scans that are still of diagnostic image quality. MATERIALS AND METHODS: In standard radiographic examinations of sinuses (anteroposterior and lateral views) with 75 kV, 20 mAs, and 3-mm aluminum filtration in 69 children (mean age, 4.2 years), the dose-area-product (DAP; mGy x cm2) was measured and converted to effective dose (mSv) according to coefficients published by the British National Radiological Protection Board. Another group of 125 children (mean age, 6.8 years) underwent low-dose MDCT of the sinuses with 6- or 16-MDCT in two phases and with different scanning protocols. An effective dose for MDCT was calculated from conversion of the dose-length-product (DLP, mGy xm) according to age. RESULTS: The mean effective dose (E) for standard radiography was 0.0528 mSv. The mean E value for low-dose MDCT was 0.096 mSv in the first phase of the study but could be lowered in the second phase to 0.0531 mSv by a combination of higher pitch and faster scan rotation time in our scan protocols, which results in diagnostic image quality at a very low dose. Statistical analysis showed no significant differences in effective dose between radiography and MDCT of the second phase. CONCLUSION: With modern MDCT technology, low-dose CT of the sinuses in children can yield diagnostic image quality using an effective dose comparable to that used for standard radiography.     

Skeletal and dento-alveolar stability after surgical-orthodontic treatment of anterior open bite: a retrospective study.

The aim of this investigation was to assess skeletal and dento-alveolar stability after surgical-orthodontic correction of skeletal anterior open bite treated by maxillary intrusion (group A) versus extrusion (group B). The cephalometric records of 49 adult anterior open bite patients (group A: n = 38, group B: n = 11), treated by the same maxillofacial surgeon, were examined at different timepoints, i.e. at the start of the orthodontic treatment (T1), before surgery (T2), immediately after surgery (T3), early post-operatively (+/- 20 weeks, T4) and one year post-operatively (T5). A bimaxillary operation was performed in 31 of the patients in group A and in six in group B. Rigid internal fixation was standard. If maxillary expansion was necessary, surgically assisted rapid palatal expansion (SRPE) was performed at least 9 months before the Le Fort I osteotomy. Forty-five patients received combined surgical and orthodontic treatment. The surgical open bite reduction (A, mean 3.9 mm; B, mean 7.7 mm) and the increase of overbite (A, mean 2.4 mm; B, mean 2.7 mm), remained stable one year post-operatively. SNA (T2-T3), showed a high tendency for relapse. The clockwise rotation of the palatal plane (1.7 degrees; T2-T3), relapsed completely within the first post-operative year. Anterior facial height reduction (A, mean -5.5 mm; B, mean -0.8 mm) occurred at the time of surgery. It can be concluded that open bite patients, treated by posterior Le Fort I impaction as well as with anterior extrusion, with or without an additional bilateral sagittal split osteotomy (BSSO), one year post-surgery, exhibit relatively good clinical dental and skeletal stability.