Eamonn Delahunt

Altered Neuromuscular Control and Ankle Joint Kinematics During Walking in Subjects With Functional Instability of the Ankle Joint

Background The ankle joint requires very precise neuromuscular control during the transition from terminal swing to the early stance phase of the gait cycle. Altered ankle joint arthrokinematics and muscular activity have been cited as potential factors that may lead to an inversion sprain during the aforementioned time periods. However, to date, no study has investigated patterns of muscle activity and 3D joint kinematics simultaneously in a group of subjects with functional instability compared with a noninjured control group during these phases of the gait cycle. Purpose To compare the patterns of lower limb 3D joint kinematics and electromyographic activity during treadmill walking in a group of subjects with functional instability with those observed in a control group. Study Design Controlled laboratory study. Methods Three-dimensional angular velocities and displacements of the hip, knee, and ankle joints, as well as surface electromyography of the rectus femoris, peroneus longus, tibialis anterior, and soleus muscles, were recorded simultaneously while subjects walked on a treadmill at a velocity of 4 km/h. Results Before heel strike, subjects with functional instability exhibited a decrease in vertical foot-floor clearance (12.62 vs 22.84 mm; P <. 05), as well as exhibiting a more inverted position of the ankle joint before, at, and immediately after heel strike (1.69°, 2.10°, and -0.09° vs -1.43°, -1.43°, and -2.78°, respectively [minus value = eversion]; P <. 05) compared with controls. Subjects with functional instability were also observed to have an increase in peroneus longus integral electromyography during the post–heel strike time period (107.91%[.dotmath]millisecond vs 64.53%[.dotmath]millisecond; P <. 01). Conclusion The altered kinematics observed in this study could explain the reason subjects with functional instability experience repeated episodes of ankle inversion injury in situations with only slight or no external provocation. It is hypothesized that the observed increase in peroneus longus activity may be the result of a change in preprogrammed feed-forward motor control.

Selection criteria for patients with chronic ankle instability in controlled research: a position statement of the international ankle consortium

The International Ankle Consortium is an international community of researchers and clinicians whose primary scholastic purpose is to promote scholarship and dissemination of research-informed knowledge related to pathologies of the ankle complex. The constituents of the International Ankle Consortium and other similar organizations have yet to properly define the clinical phenomenon known as chronic ankle instability (CAI) and its related characteristics for consistent patient recruitment and advancement of research in this area. Although research on CAI and awareness of its impact on society and healthcare systems have grown substantially in the last 2 decades, the inconsistency in participant/patient selection criteria across studies presents a potential obstacle to addressing the problem properly. This major gap within the literature limits the ability to generalize this evidence to the target patient population. Therefore, there is a need to provide standards for patient/participant selection criteria in research focused on CAI, with justifications using the best available evidence.

Doha agreement meeting on terminology and definitions in groin pain in athletes

Background Heterogeneous taxonomy of groin injuries in athletes adds confusion to this complicated area. Aim The ‘Doha agreement meeting on terminology and definitions in groin pain in athletes’ was convened to attempt to resolve this problem. Our aim was to agree on a standard terminology, along with accompanying definitions. Methods A one-day agreement meeting was held on 4 November 2014. Twenty-four international experts from 14 different countries participated. Systematic reviews were performed to give an up-to-date synthesis of the current evidence on major topics concerning groin pain in athletes. All members participated in a Delphi questionnaire prior to the meeting. Results Unanimous agreement was reached on the following terminology. The classification system has three major subheadings of groin pain in athletes: 1. Defined clinical entities for groin pain: Adductor-related, iliopsoas-related, inguinal-related and pubic-related groin pain. 2. Hip-related groin pain. 3. Other causes of groin pain in athletes. The definitions are included in this paper. Conclusions The Doha agreement meeting on terminology and definitions in groin pain in athletes reached a consensus on a clinically based taxonomy using three major categories. These definitions and terminology are based on history and physical examination to categorise athletes, making it simple and suitable for both clinical practice and research.

Patellofemoral pain syndrome: a review on the associated neuromuscular deficits and current treatment options

Background: Patellofemoral pain syndrome (PFPS) is a common clinical presentation. Various neuromuscular factors have been reported to contribute to its aetiology. Study design: Systematic review Methods: A literature search was carried out from 1998 up to December 2007. Eligible studies were those that: (1) examined the effects of hip strengthening in subjects with PFPS; (2) examined the effects of physiotherapy treatment aimed at restoring muscle balance between the vastus medialis oblique (VMO) and vastus lateralis (VL) in subjects with PFPS; (3) examined the effect of taping on electromyogram (EMG) muscle amplitude in subjects with PFPS; and (4) compared the effects of open versus closed kinetic chain exercises in the treatment of subjects with PFPS. Results and conclusion: No randomised controlled trials exist to support the use of hip joint strengthening in subjects with PFPS. Physiotherapy treatment programmes appear to be an efficacious method of improving quadriceps muscle imbalances. Further studies are required to determine the true efficacy of therapeutic patellar taping. Both open and closed kinetic chain exercises are appropriate forms of treatment for subjects with PFPS.

Ankle function during hopping in subjects with functional instability of the ankle joint

A common mechanism of inversion injury involves a lateral movement producing a hypersupination of the ankle joint. To date, no study has investigated patterns of muscle activity, three‐dimensional (3D) joint kinematics and kinetics simultaneously in a group of subjects with functional instability (FI) compared with a non‐injured control group during a lateral hopping test. Twenty‐six subjects with the subjective complaint of FI of the ankle joint and 24 non‐injured healthy control subjects volunteered to participate in the study. We measured 3D lower limb kinematics, kinetics and surface electromyography (EMG) of the rectus femoris, tibialis anterior, peroneus longus and soleus muscle in all subjects during a lateral hop task for the period 200 ms pre‐ and post‐initial contact (IC). FI subjects were observed to have a less‐everted position of the ankle joint during the time period from 45 ms pre‐IC to 95 ms post‐IC (P<0.05). FI subjects were also found to have an increase in pre‐ and post‐IC rectus femoris, tibialis anterior and solues EMG activity. The results suggest that subjects with FI exhibit changes in ankle joint movement and neuromuscular control that could predispose to further injury.

Treatment of Common Deficits Associated with Chronic Ankle Instability

Lateral ankle sprains are amongst the most common injuries incurred by athletes, with the high rate of reoccurrence after initial injury becoming of great concern. Chronic ankle instability (CAI) refers to the development of repetitive ankle sprains and persistent residual symptoms post-injury. Some of the initial symptoms that occur in acute sprains may persist for at least 6 months post-injury in the absence of recurrent sprains, despite the athlete having returned to full functional activity. CAI is generally thought to be caused by mechanical instability (MI) or functional instability (FI), or both. Although previously discussed as separate entities, recent research has demonstrated that deficits associated with both MI and FI may co-exist to result in CAI.For clinicians, the main deficits associated with CAI include deficits in proprioception, neuromuscular control, strength and postural control. Based on the literature reviewed, it does seem that subjects with CAI have a deficit in frontal plane ankle joint positional sense. Subjects with CAI do not appear to exhibit any increased latency in the peroneal muscles in response to an external perturbation. Preliminary data suggest that feed-forward neuromuscular control may be more important than feed-back neuromuscular control and interventions are now required to address deficits in feed-forward neuromuscular control. Balance training protocols have consistently been shown to improve postural stability in subjects with CAI. Subjects with CAI do not experience decreased peroneus longus strength, but instead may experience strength deficits in the ankle joint invertor muscles. These findings are of great clinical significance in terms of understanding the mechanisms and deficits associated with CAI. An appreciation of these is vital to allow clinicians to develop effective prevention and treatment programmes in relation to CAI.

Characteristics of people with recurrent ankle sprains: a systematic review with meta-analysis

Objective To examine whether people with recurrent ankle sprain, have specific physical and sensorimotor deficits. Design A systematic review of journal articles in English using electronic databases to September 2009. Included articles compared physical or sensorimotor measures in people with recurrent (≥2) ankle sprains and uninjured controls. Main outcome groups Outcome measures were grouped into: physical characteristics, strength, postural stability, proprioception, response to perturbation, biomechanics and functional tests. A meta-analysis was undertaken where comparable results within an outcome group were inconsistent. Results Fifty-five articles met the inclusion criteria. Compared with healthy controls, people with recurrent sprains demonstrated radiographic changes in the talus, changes in foot position during gait and prolonged time to stabilisation after a jump. There were no differences in ankle range of motion or functional test performance. Pooled results showed greater postural sway when standing with eyes closed (SMD=0.9, 95% CI 0.4 to 1.4) or on unstable surfaces (0.5, 0.1 to 1.0) and decreased concentric inversion strength (1.1, 0.2 to 2.1) but no difference in evertor strength, inversion joint position sense or peroneal latency in response to a perturbation. Conclusion There are specific impairments in people with recurrent ankle sprain but not necessarily in areas commonly investigated.

A Comparison Between Performance on Selected Directions of the Star Excursion Balance Test and the Y Balance Test

CONTEXT The Star Excursion Balance Test (SEBT) is a widely accepted method of assessing dynamic postural stability. The Y Balance Test (YBT) is a commercially available device for measuring balance that uses 3 (anterior, posteromedial, and posterolateral) of the 8 SEBT directions and has been advocated as a method for assessing dynamic balance. To date, no studies have compared reach performance in these tests in a healthy population. OBJECTIVE To determine whether any differences exist between reach distance performance for the anterior, posteromedial, and posterolateral directions of the SEBT and the YBT. DESIGN Descriptive laboratory study. SETTING University motion analysis laboratory. PATIENTS OR OTHER PARTICIPANTS A total of 20 healthy active male participants (age = 22.50 ± 3.05 years, height = 1.78 ± 0.82 m, weight = 79.48 ± 11.32 kg, body mass index = 24.96 ± 2.56 kg/m²). INTERVENTION(S) Participants carried out 3 trials in each reach direction on each leg on the SEBT and the YBT a minimum of 1 week apart. MAIN OUTCOME MEASURE(S) The means of the 3 trials in each direction on each leg on both tests were calculated. Data were collected after 4 practice trials in each direction. Paired t tests and Bland-Altman plots were used to compare reach distances between the SEBT and the YBT. RESULTS Participants reached farther in the anterior direction on the SEBT than on the YBT. No differences were observed in the posteromedial and posterolateral directions. CONCLUSIONS Differing postural-control strategies may be used to complete these tasks. This finding has implications for the implementation and interpretation of these dynamic balance tests.

Evidence review for the 2016 International Ankle Consortium consensus statement on the prevalence, impact and long-term consequences of lateral ankle sprains.

Lateral ankle sprains (LASs) are the most prevalent musculoskeletal injury in physically active populations. They also have a high prevalence in the general population and pose a substantial healthcare burden. The recurrence rates of LASs are high, leading to a large percentage of patients with LAS developing chronic ankle instability. This chronicity is associated with decreased physical activity levels and quality of life and associates with increasing rates of post-traumatic ankle osteoarthritis, all of which generate financial costs that are larger than many have realised. The literature review that follows expands this paradigm and introduces emerging areas that should be prioritised for continued research, supporting a companion position statement paper that proposes recommendations for using this summary of information, and needs for specific future research.

Lower limb kinematic alterations during drop vertical jumps in female athletes who have undergone anterior cruciate ligament reconstruction

The aim of this study was to determine if anterior cruciate ligament reconstructed (ACL‐R) female athletes exhibit altered lower limb kinematic profiles during jump landing when compared to a non‐injured age, sex, and activity matched control group. Fourteen ACL‐R and 14 non‐injured control subjects performed 3 vertical drop jump (DVJ) trials. Lower limb kinematics were recorded at 200 Hz. Peak and time‐averaged angular displacements were quantified and utilized for between‐group analysis. The ACL‐R group displayed altered hip joint frontal and transverse plane kinematic alterations, and knee joint frontal and sagittal plane kinematic alterations. Specifically the ACL‐R group displayed an increased adducted (p < 0.05) and internally rotated (p < 0.05) hip joint position, both peak and time‐averaged, following landing. The ACL‐R group also displayed a decreased adducted (p < 0.05) and flexed (p < 0.05) position of the knee joint following landing. The observed aberrant lower limb kinematics could pre‐dispose ACL‐R athletes to potential future knee joint injuries. Further studies are required to determine in a prospective manner whether such deficits increase the incidence of recurrent ACL injury, and whether specific sensorimotor protocols following ACL reconstruction can minimize these kinematic deficits.