Effects of barefoot and footwear conditions on learning of a dynamic balance task: a randomized controlled study

Informing wobble-board training and assessment through an investigation of the effect of biological-sex, anthropometrics, footwear and dual-tasking in young adults

BACKGROUND

Despite wobble board use being common in physiotherapy the effect of certain factors, essential to clinical reasoning, have not been investigated.

OBJECTIVE

To determine the effect of biological sex, anthropometrics, footwear and dual tasking (DT) on wobble board balance performance.

METHODS

Eighty-six healthy participants (44 females) had their wobble board performance measured during double-leg-stance (DLS) with eyes open (DLSEO), closed (DLSEC) and single-leg-stance (SLS) tasks, with and without footwear and a DT added. Anthropometrics were also measured.

RESULTS

Females outperformed males during most tasks, with some large effect sizes (ES). Performance was moderately related to weight and shoulder, waist and hip circumference. Overall, there were no differences between footwear and no footwear, except for males during SLS. DT made little difference, except during DLSEO and SLS, where single task was better than DT, though only females had a large ES.

CONCLUSION

During wobble board tasks, biological sex differences were observed and a modest correlation between anthropometrics and performance noted. DT and footwear had minimal effect.

Perturbation-based Balance Training to improve postural responses and falls in people with multiple sclerosis: a randomized controlled trial

PURPOSE

To determine the effects of Perturbation-based Balance Training (PBT) on postural responses and falls in people with multiple sclerosis (PwMS) and compare the results with conventional balance training (CBT).

MATERIALS AND METHODS

Thirty-four PwMS were randomized to receive 4 weeks of PBT or CBT. Latency of postural responses to external perturbations, Timed-Up-and-Go (TUG), 10-meter-walk (10MW), Berg Balance Scale (BBS), and Activities-specific Balance Confidence Scale (ABC) were measured at baseline and post-training. Also, the proportion of fallers and fall rate were assessed at a 3-month follow-up.

RESULTS

The latency of postural responses significantly decreased in PBT compared to CBT. TUG, 10MW, BBS, and ABC, at post-training, and relative risk of falls and fall rate at 3-month follow-up had no statistically significant between-group differences.

CONCLUSIONS

The results show that PBT is at least as effective as CBT in improving balance and decreasing falls, while it has superiority over CBT whenever the clinicians mainly aim to improve reactive balance strategies. Future studies with a larger sample size are warranted to complement the results of this study.Implication for rehabilitationPerturbation-based Balance Training is at least as effective as conventional balance training (CBT) in improving proactive postural control in people with multiple sclerosis (PwMS).Perturbation-based Balance Training has superiority over CBT in improving reactive postural control in PwMS.Perturbation-based Balance Training has no superiority over CBT in improving fall-related outcomes.

Footwear Type and Testing Environment Do Not Affect Baseline Modified Balance Error Scoring System Performance Among Middle School Athletes

CONTEXT

Limited evidence exists to demonstrate the effect of extrinsic factors, such as footwear worn or the testing environment, on performance of the modified balance error scoring system (mBESS) in the middle school age (10-14 y) population. Therefore, the purpose of our study was to investigate the effect of footwear types and testing environments on performance of the mBESS by middle school athletes.

DESIGN

Cross-sectional.

METHODS

In total, 2667 middle school athletes (55.9% boys and 44.1% girls; age = 12.3 [0.94] y) were administered the mBESS while wearing their self-selected footwear (barefoot, cleats, or shoes) either indoors (basketball court) or outdoors (football field or track). The number of errors committed (range = 0-10) during the double-leg, single-leg, and tandem stances of the mBESS were summed to calculate a total score (range = 0-30). Kruskal-Wallis tests were used to assess for differences among the footwear groups for each mBESS stance and the total score. Mann-Whitney U tests with calculated nonparametric effect sizes (r) were used to assess for differences between the footwear groups and testing environments when appropriate.

RESULTS

There were significant differences for the number of committed errors among the footwear groups in the single-leg (P < .001) and tandem (P < .001) stances of the mBESS and mBESS total scores (P < .001). Significantly fewer errors (better) were committed while wearing shoes compared with other footwear in the single-leg and tandem stances of the mBESS (Ps ≤ .032, r = .07-.13). Participants assessed indoors committed significantly fewer errors than those assessed outdoors in each stance of the mBESS (Ps ≤ .022, r = .04-.14). Lower (better) mBESS total scores were observed for participants while wearing shoes (Ps ≤ .002, r = .10-.15) or assessed indoors (P = .001, r = .14).

CONCLUSIONS

Although our data suggest that the type of footwear worn and the testing environment have a significant effect on mBESS scores of middle school athletes, the magnitudes of these differences are negligible.

Parents, health professionals and footwear stakeholders' beliefs on the importance of different features of young children's footwear: a qualitative study

Background

A small but building pool of evidence of the impact of footwear on children’s function means understanding the different beliefs of stakeholders about footwear key features and flexibility is critical for translation into recommendations and to support parents and caregivers in purchasing footwear for their children. Therefore, this research aimed to describe how different stakeholders (health professionals, parents, and footwear industry representatives) described the importance of flexibility and other footwear features for young children.

Methods

This qualitative study was nested within an international modified Delphi online survey. Participants responded to open-ended questions about footwear component flexibility and asked if and why flexibility in these areas were important. Participants also described any other important footwear features. Inductive thematic analysis was used to generate themes.

Results

There were 121 responses from three stakeholder groups including health professionals (n = 90), parents of young children (n = 26) and footwear industry representatives (n = 5). Overarching themes described by participants included developmental impacts of footwear, therapeutic impact and how footwear may play a role in function.

Conclusion

There were key differences in how stakeholders viewed footwear and any perceived benefits of footwear components, much of which was not backed with empirical evidence. It was also identified that health professionals are using footwear within treatment recommendations. This work highlights the importance of understanding circumstances in which footwear may have a therapeutic impact or be the first line of treatment for children with complex foot needs. This is the first step in developing contemporary footwear recommendations for parents and caregivers.

Young children's footwear taxonomy: An international Delphi survey of parents, health and footwear industry professionals

OBJECTIVE

There is little consistency between commercial grade footwear brands for determining shoe sizing, and no universally accepted descriptors of common types or features of footwear. The primary aim of this research was to develop a footwear taxonomy about the agreed types of footwear commonly worn by children under the age of six. Secondary aims were to gain consensus of the common footwear features, when different types of footwear would be commonly worn, common terms for key footwear parts, and how movement at some of these footwear parts should be described.

MATERIALS AND METHODS

Opinions were collected through a three-round modified Delphi international online survey from parents, health professionals, researchers, and footwear industry professionals. The first survey displayed generic pictures about different footwear types and asked participants to provide a grouping term, when the footwear would be worn (for what type of activity) and any grouping features. The second and third rounds presented consensus and gathered agreement on statements.

RESULTS

There were 121 participants who provided detailed feedback to open-ended questions. The final round resulted in consensus and agreement on the names of 14 different footwear types, when they are commonly worn and their common features. Participants also reached consensus and agreement on the terms heel counter to describe the back part of footwear and fixtures as the collective term for features allowing footwear adjustability and fastening. They also agreed on terms to quantify the flexibility at footwear sole (bend or twist) or the heel counter.

CONCLUSION

This first taxonomy of children's footwear represents consensus amongst different stakeholders and is an important step in promoting consistency within footwear research. One shoe does not fit all purposes, and the recommendations from this work help to inform the next steps towards ensuring greater transparency and commonality with footwear recommendations.

Influence of footwear on postural sway: A systematic review and meta-analysis on barefoot and shod bipedal static posturography in patients and healthy subjects

BACKGROUND

Bipedal static posturography is widely used to assess postural control. However, standardized methods and evidence on the influence of footwear on balance in comparison to barefoot stance is sparse.

RESEARCH QUESTIONS

Is bipedal static posturography applied in a standardized way with respect to demographics and the experimental set-up (systematic review)? Does habitual footwear influence postural control in comparison to barefoot condition during bipedal static posturography in adult patients and healthy subjects (meta-analysis)?

METHODS

For this systematic review and meta-analysis, a comprehensive follow-up literature search was conducted from March 2009 until January 2020 according to the PRISMA guidelines. Original, research articles reporting on bipedal, unsupported, static posturography in adults (≥18 years) were included according to inclusion criteria (age, sex, height, weight, duration, repetitions, visual/foot condition, sampling frequency). Studies comparing habitual footwear with barefoot condition during bipedal static posturography were included for the meta-analysis. Center of pressure parameters (sway velocity, range, root mean square, paths lengths) with subjects having eyes closed (EC) or open (EO) were analyzed using random effects models.

RESULTS

For this systematic review and meta-analysis, 207 and eight out of 5189 studies with 12'341 and 156 subjects, respectively, were eligible. Most studies (89%) reported barefoot, 5% shod, and 6% barefoot and shod measurements. Less than half of studies (44%) included patients of which the minority (13%) suffered from neurological disease. Sway velocity in the anterior-posterior direction was higher in habitual shoes compared to barefoot with EC (SMD: 1.08; 95% CI: 0.68-1.48; p < 0.01; I² = 0%), with EO (SMD: 0.68; 95% CI: 0.11-1.26; p = 0.02; I² = 1%), and in the medio-lateral direction with EC (SMD: 1.30; 95% CI: 0.76-1.85, p < 0.01; I² = 37%).

SIGNIFICANCE

Methodical heterogeneity of bipedal static posturography hampers studies' comparability. Thus, we provide a standardized approach to increase knowledge whether habitual footwear decrease postural control in comparison to barefoot stance.

Effects of Typical Athletic Shoes on Postural Balance According to Foot Type

BACKGROUND

The effects of shoes and foot type on balance are unclear. We aimed to investigate the differences between static and dynamic balance among three foot types and the changes in postural balance while wearing typical athletic shoes.

METHODS

Based on the Foot Posture Index, the feet of 39 participants were classified as pronated, neutral, or supinated by a physiatrist. Static and dynamic balance function were assessed by center of gravity (COG) sway velocity with eyes open and eyes closed and a modified Star Excursion Balance Test in a random order with participants either barefoot or wearing shoes.

RESULTS

The COG sway velocity was significantly higher in the supinated foot group than in the neutral foot group (barefoot: eyes open, P = .004, eyes closed, P = .001). Normalized composite reach distance (NCRD) was significantly lower in the pronated and supinated foot groups (barefoot: P = .039, P = .008; shoes: P = .018, P = .018). In all three foot type groups, COG sway velocity was significantly decreased (P < .05) and NCRD was significantly increased (P < .05) while wearing typical athletic shoes.

CONCLUSIONS

The medial longitudinal arch of the foot affects postural balance. Typical athletic shoes improve postural balance regardless of foot type. However, the pronated and supinated foot groups still had lower dynamic postural balance compared with the neutral foot group, even when wearing athletic shoes. People with pronated and supinated feet may need additional interventions, such as foot orthoses or balance training.

Running barefoot leads to lower running stability compared to shod running - results from a randomized controlled study

Local dynamic running stability is the ability of a dynamic system to compensate for small perturbations during running. While the immediate effects of footwear on running biomechanics are frequently investigated, no research has studied the long-term effects of barefoot vs. shod running on local dynamic running stability. In this randomized single-blinded controlled trial, young adults novice to barefoot running were randomly allocated to a barefoot or a cushioned footwear running group. Over an 8-week-period, both groups performed a weekly 15-min treadmill running intervention in the allocated condition at 70% of their VO2 max velocity. During each session, an inertial measurement unit on the tibia recorded kinematic data (angular velocity) which was used to determine the short-time largest Lyapunov exponents as a measure of local dynamic running stability. One hundred running gait cycles at the beginning, middle, and end of each running session were analysed using one mixed linear multilevel random intercept model. Of the 41 included participants (48.8% females), 37 completed the study (drop-out = 9.7%). Participants in the barefoot running group exhibited lower running stability than in the shod running group (p = 0.037) with no changes during the intervention period (p = 0.997). Within a single session, running stability decreased over the course of the 15-min run (p = 0.012) without differences between both groups (p = 0.060). Changing from shod to barefoot running reduces running stability not only in the acute phase but also in the longer term. While running stability is a relatively new concept, it enables further insight into the biomechanical influence of footwear.

Acute exercise following skill practice promotes motor memory consolidation in Parkinson's disease

Acute cardiovascular exercise has shown to promote neuroplastic processes supporting the consolidation of newly acquired motor skills in healthy adults. First results suggest that this concept may be transferred to populations with motor and cognitive dysfunctions. In this context, Parkinson's disease (PD) is highly relevant since patients demonstrate deficits in motor learning. Hence, in the present study we sought to explore the effect of a single post-practice exercise bout on motor memory consolidation in PD. For this purpose, 17 patients with PD (Hoehn and Yahr: 1 - 2.5, age: 60.1 ± 7.9 y) practiced a whole-body skill followed by either (i) a moderate-intense bout of cycling, or (ii) seated rest for a total of 30 min. The motor skill required the participants to balance on a tiltable platform (stabilometer) for 30 s. During skill practice, participants performed 15 trials followed by a retention test 1 day and 7 days later. We calculated time in balance (platform within ± 5° from horizontal) for each trial and within- and between-group differences in memory consolidation (i.e. offline learning = skill change from last acquisition block to retention tests) were analyzed. Groups revealed similar improvements during skill practice (F_4,60 = 0.316, p = 0.866), but showed differences in offline learning, which were only evident after 7 days (F_1,14 = 5.602, p = 0.033). Our results suggest that a single post-practice exercise bout is effective in enhancing long-term motor memory consolidation in a population with motor learning impairments. This may point at unique promoting effects of exercise on dopamine neurotransmission involved in memory formation. Future studies should investigate the potential role of exercise-induced effects on the dopaminergic system.

Is an Elastic Ankle Support Effective in Improving Jump Landing Performance, and Static and Dynamic Balance in Young Adults With and Without Chronic Ankle Instability?

CONTEXT

In some patients, ankle sprains lead to chronic symptoms like pain or muscular weakness called chronic ankle instability (CAI). External ankle supports have shown to be effective in preventing sprains and reducing recurrence, but the underlying mechanisms are unclear. As sensorimotor variables are associated with injury incidence, an influence of external ankle support on landing performance and balance seems plausible.

OBJECTIVE

To analyze the effects of an elastic ankle support on jump landing performance and static and dynamic balance in patients with CAI and healthy controls.

DESIGN

Crossover study.

SETTING

Functional tests in a laboratory setting.

PATIENTS OR OTHER PARTICIPANTS

Twenty healthy students and 20 patients with CAI were included for study participation based on their scores in ankle stability and function questionnaires.

INTERVENTION

Healthy and CAI participants performed each test with and without an elastic ankle support.

MAIN OUTCOME MEASURES

(1) Jump landing performance was measured with the Landing Error Scoring System, (2) static balance was assessed with the Balance Error Scoring System, and (3) dynamic balance was assessed using the Y Balance Test. Linear mixed models were used to analyze the effects of the elastic ankle support on sensorimotor parameters.

RESULTS

Healthy controls performed significantly better in the Landing Error Scoring System (P = .01) and Y Balance Test anterior direction (P = .01). No significant effects of elastic ankle support on Landing Error Scoring System, Balance Error Scoring System, or Y Balance Test performance were observed in the CAI or control group. There were no significant group-by-ankle support interactions.

CONCLUSIONS

In the current study, the acute use of elastic ankle support was ineffective for enhancing jump landing performance, and static and dynamic balance. Further research is needed to identify the underlying mechanisms of the preventive effects of elastic ankle support.

The Role of Footwear in the Pathogenesis of Hallux Valgus: A Proof-of-Concept Finite Element Analysis in Recent Humans and Homo naledi

Hallux valgus (HV), the bunion of the first metatarsophalangeal joint (MTPJ), bothers many adults. No consensus has been reached about the causes of HV, be it a hereditary, or acquired, or multifactorial disease. Nor has agreement been reached using MTPJ angle to assess HV based on X-ray because in most cases the assessment of MTPJ is not reliable as it depends on the posture during scanning. In this study, we assume that HV is predominately acquired and that shoe wearing per se is an important player in HV pathogenesis. To verify our hypothesis, a CT-based finite element (FE) model of the first MTPJ of fossil remains of bear-footed Homo naledi was created and compared to that of five contemporary shoe-wearing wrestlers (10 models from two scans at an interval of about 18 months) because Homo naledi's first MTPJ is an ideal model for non-shoe wearing with parallel sesamoid grooves. We developed the first MTPJ structure transformation method and created MTPJ joint capsule model for both Homo naledi and wrestlers. Constraint on the medial side of the first MTPJ capsule was set to simulate shoe-wearing conditions compared to the lack of medial constraint for barefooted conditions. Analysis of eight FE models of different angles for the first MTPJ of Homo naledi was performed by the first MTPJ transformation method and results showed that stress concentrated on the medial capsule of the first MTPJ in simulated shoe-wearing conditions, even at MTPJ angle of 0°. Increase in the first MTPJ angle further increased stress concentration on the medial side, and stress-growth relationship might reveal the causes of HV. We further developed a method to position the first MTPJ in wrestlers and created CT-based models at two time points. It was evident that the first MTPJ angle increased in all but one athlete, with a maximal increase of 4.03 degrees. This verifies our hypothesis that HV might be developed by wearing shoes. Further longitudinal studies with larger sample sizes are needed to additionally validate our results and determine the magnitude of the effects of shoe wearing on development and progression of HV.

Six weeks of balance or power training induce no generalizable improvements in balance performance in healthy young adults

Background

Training programs for fall prevention often fail to induce large general effects. To improve the efficacy of fall prevention programs, it is crucial to determine which type of training is most effective in inducing generalizable effects, i.e., improvements in untrained situations. Two likely candidates are balance and resistance training. Here, we assessed whether either varied balance training or a training program aiming to increase leg power would improve performance and acquisition rate of a novel balance task.

Methods

Forty-two healthy recreationally active subjects (16 females, age 24 ± 3y) were assigned to a control group, a varied practice balance group or a loaded squat and plyometrics power group, training for 6 weeks (twice per week, 40 min per session). Before and after the training, we measured peak power in countermovement jumps and balance performance in two different untrained balance tasks (10 trials pre and 50 trials post-training).

Results

After training, the performance and the acquisition rate in the two untrained tasks were similar for all groups (no group x time interaction), i.e., no generalization of learning effect was induced by either form of training. Peak power in the countermovement jump did not change significantly in any of the groups.

Conclusions

Neither a six-week power training nor a varied balance training improved performance or acquisition of an untrained balance task. This underpins the task-specificity principle of training and emphasizes the need for studies that assess the mechanisms of transfer and generalization, thus helping to find more effective intervention programs for fall prevention.

Adaptation of Running Biomechanics to Repeated Barefoot Running: A Randomized Controlled Study

BACKGROUND

Previous studies have shown that changing acutely from shod to barefoot running induces several changes to running biomechanics, such as altered ankle kinematics, reduced ground-reaction forces, and reduced loading rates. However, uncertainty exists whether these effects still exist after a short period of barefoot running habituation.

PURPOSE/HYPOTHESIS

The purpose was to investigate the effects of a habituation to barefoot versus shod running on running biomechanics. It was hypothesized that a habituation to barefoot running would induce different adaptations of running kinetics and kinematics as compared with a habituation to cushioned footwear running or no habituation.

STUDY DESIGN

Controlled laboratory study.

METHODS

Young, physically active adults without experience in barefoot running were randomly allocated to a barefoot habituation group, a cushioned footwear group, or a passive control group. The 8-week intervention in the barefoot and footwear groups consisted of 15 minutes of treadmill running at 70% of VO₂ max (maximal oxygen consumption) velocity per weekly session in the allocated footwear. Before and after the intervention period, a 3-dimensional biomechanical analysis for barefoot and shod running was conducted on an instrumented treadmill. The passive control group did not receive any intervention but was also tested prior to and after 8 weeks. Pre- to posttest changes in kinematics, kinetics, and spatiotemporal parameters were then analyzed with a mixed effects model.

RESULTS

Of the 60 included participants (51.7% female; mean ± SD age, 25.4 ± 3.3 years; body mass index, 22.6 ± 2.1 kg·m^-2), 53 completed the study (19 in the barefoot habituation group, 18 in the shod habituation group, and 16 in the passive control group). Acutely, running barefoot versus shod influenced foot strike index and ankle, foot, and knee angles at ground contact (P < .001), as well as vertical average loading rate (P = .003), peak force (P < .001), contact time (P < .001), flight time (P < .001), step length (P < .001), and cadence (P < .001). No differences were found for average force (P = .391). After the barefoot habituation period, participants exhibited more anterior foot placement (P = .006) when running barefoot, while no changes were observed in the footwear condition. Furthermore, barefoot habituation increased the vertical average loading rates in both conditions (barefoot, P = .01; shod, P = .003) and average vertical ground-reaction forces for shod running (P = .039). All other outcomes (ankle, foot, and knee angles at ground contact and flight time, contact time, cadence, and peak forces) did not change significantly after the 8-week habituation.

CONCLUSION

Changing acutely from shod to barefoot running in a habitually shod population increased the foot strike index and reduced ground-reaction force and loading rates. After the habituation to barefoot running, the foot strike index was further increased, while the force and average loading rates also increased as compared with the acute barefoot running situation. The increased average loading rate is contradictory to other studies on acute adaptations of barefoot running.

CLINICAL RELEVANCE

A habituation to barefoot running led to increased vertical average loading rates. This finding was unexpected and questions the generalizability of acute adaptations to long-term barefoot running. Sports medicine professionals should consider these adaptations in their recommendations regarding barefoot running as a possible measure for running injury prevention.

REGISTRATION

DRKS00011073 (German Clinical Trial Register).

Three months of slackline training elicit only task-specific improvements in balance performance

Slackline training is a challenging and motivating type of balance training, with potential usefulness for fall prevention and balance rehabilitation. However, short-term slackline training seems to elicit mostly task-specific performance improvements, reducing its potential for general fall prevention programs. It was tested whether a longer duration slackline training (three months, 2 sessions per week) would induce a transfer to untrained tasks. Balance performance was tested pre and post slackline training on the slackline used during the training, on a slackline with different slack, and in 5 different non-trained static and dynamic balance tasks (N training = 12, N control = 14). After the training, the training group increased their performance more than the control group in both of the slackline tasks, i.e. walking on the slackline (time × group interaction with p < 0.001 for both tasks). However, no differences between groups were found for the 5 non-trained balance tasks, only a main effect of time for four of them. The long-term slackline training elicited large task-specific performance improvements but no transfer to other non-trained balance tasks. The extensive slackline training that clearly enhanced slackline performance did not improve the capability to keep balance in other tasks and thus cannot be recommended as a general fall prevention program. The significant test-retest effect seen in most of the tested tasks emphasizes the need of a control group to adequately interpret changes in performance following balance training.