Nili Steinberg

Gait training with real-time augmented toe-ground clearance information decreases tripping risk in older adults and a person with chronic stroke.

Falls risk increases with ageing but is substantially higher in people with stroke. Tripping-related balance loss is the primary cause of falls, and Minimum Toe Clearance (MTC) during walking is closely linked to tripping risk. The aim of this study was to determine whether real-time augmented information of toe-ground clearance at MTC can increase toe clearance, and reduce tripping risk. Nine healthy older adults (76 ± 9 years) and one 71 year old female stroke patient participated. Vertical toe displacement was displayed in real-time such that participants could adjust their toe clearance during treadmill walking. Participants undertook a session of unconstrained walking (no-feedback baseline) and, in a subsequent Feedback condition, were asked to modify their swing phase trajectory to match a “target” increased MTC. Tripping probability (PT) pre- and post-training was calculated by modeling MTC distributions. Older adults showed significantly higher mean MTC for the post-training retention session (27.7 ± 3.79 mm) compared to the normal walking trial (14.1 ± 8.3 mm). The PT on a 1 cm obstacle for the older adults reduced from 1 in 578 strides to 1 in 105,988 strides. With gait training the stroke patient increased MTC and reduced variability (baseline 16 ± 12 mm, post-training 24 ± 8 mm) which reduced obstacle contact probability from 1 in 3 strides in baseline to 1 in 161 strides post-training. The findings confirm that concurrent visual feedback of a lower limb kinematic gait parameter is effective in changing foot trajectory control and reducing tripping probability in older adults. There is potential for further investigation of augmented feedback training across a range of gait-impaired populations, such as stroke.

Posturography Characteristics of Obese Children with and without Associated Disorders

A group of 59 obese children ages 6–12 years were interviewed for current medical diagnoses (e.g., Attention Deficit Hyperactivity Disorder- ADHD, and clumsiness) and later were examined posturographically for balance and stability. General stability of all the obese children deviated significantly from norms. 32.2% of the obese children had a pattern of balance that could indicate orthopedic problems. Obese children with ADHD or perceived clumsiness had significantly worse balance and postural performance compared to other obese children. Balance and posture among obese children without suspicion of problems were similar to non-obese controls. In conclusion, obese children with associated disorders (such as ADHD and perceived clumsiness) manifested disturbance in balance control. Thus, physical activity interventions for these children should include safety measures to decrease the chances of falling and subsequent injury.

Can textured insoles improve ankle proprioception and performance in dancers

ABSTRACT With the aim of determining both the acute and the chronic effects of textured insoles on the ankle discrimination and performance ability of dancers, 60 ballet dancers from the Australian Ballet School, aged 14–19 years, were divided into three groups (two intervention groups and a control group), age- and level-matched. In the first 5 weeks (weeks 1 to 5), the first intervention group (GRP1) was asked to wear textured insoles in their ballet shoes and the second intervention group (GRP2) was not given textured insoles to wear. In the next 5 weeks (weeks 6 to 10), GRP2 was asked to wear the same type of textured insoles and GRP1 did not wear the textured insoles. The control group (CTRL) did not wear textured insoles during the whole 10 weeks. All participants were tested preintervention, after 5 weeks and after 10 weeks for ankle discrimination score (AUC scores). Dance performance was assessed by 5–7 dance teachers. Pre-to-post change in AUC scores was significantly greater for the groups wearing insoles than for the controls (P = .046) and the size of pre-to-post changes did not differ between the two intervention groups (P = .834). Significant correlation was found between ankle discrimination score and performance scores, using the textured insoles (r = .412; P = .024). In conclusion, the stimulation to the proprioceptive system arising from textured insoles worn for five weeks was sufficient to improve the proprioceptive ability and performance ability of ballet dancers.

Longitudinal Study Evaluating Postural Balance of Young Athletes.

Repeated anaerobic conditions during athletic performance may cause general and local fatigue that result in postural balance deficit. Evidence suggests that improved postural balance during athletic training may decrease the risk for fallings and traumatic injuries among athletes. Twenty athletes (12 girls, 8 boys) and 20 controls (12 girls, 8 boys) ages 10–15 years participated in the current study. All athletes were active in an 8-month physical activity program, 3 times per week for 90 min., specific to basketball, soccer, or athletic training. The control children participated in physical education at school only, with no involvement in organized extracurricular sports. All participants were evaluated for postural balance in three assessments over one year (at 4-mo intervals); the Interactive Balance System machine (Tetrax device) was used to assess balance at three test times (pre-, post-, and 10 min) after a session of a repeated sprint anaerobic test, consisting of 12 × 20 m run starting every 20 sec. The athletes had better postural balance than controls. There were different group patterns of change over the sessions; a significant interaction of session and group indicated that postural balance of the groups differed. The contribution of low sway frequencies (F1) and high sway frequencies (F6) differed between the controls and the athletes group. Results suggested that although athletes had better postural balance, improvement should be encouraged during training over the sessions and seasons, with special awareness of the balance deficit that occurs immediately after anaerobic stress and at the end of the season, to decrease the risk of injuries.

The relationship of hip muscle performance to leg, ankle and foot injuries: a systematic review

ABSTRACT Objectives: Hip control affects movement and muscle firing patterns in the leg, ankle and foot, and may contribute to overuse injuries. Muscle performance can be measured as strength, endurance or muscle activation patterns. Our objective was to systematically review whether hip muscle performance is associated with leg, ankle and foot injuries. Data sources: A structured and comprehensive search of six medical literature databases was combined with forward and backward citation tracking (AMED, CINAHL, EMBASE, Medline, Scopus and SportDiscus). Study selection: Eligible studies measured hip muscle performance in individuals with musculoskeletal injuries below the tibial tuberosity, using dynamometry or electromyography (EMG). All studies compared an injured group with a control group or compared the injured and non-injured limb in the same individual. Data extraction: Data was extracted from each study independently by two authors. Data synthesis: Twenty case-control and four prospective studies (n = 24) met the inclusion criteria. Injury classifications included chronic ankle instability (n = 18), Achilles tendinopathy (n = 2), medial tibial stress syndrome and tibial stress fracture (n = 1), posterior tibial tendon dysfunction (n = 1), and exertional medial tibial pain (n = 2). Eleven of the studies revealed differences in hip muscle performance indicating less strength, delayed onset activation and decreased duration of activation in the injured groups. Two studies found evidence for differences between groups only in some of their measurements. Three out of the four prospective studies revealed that hip muscle performance was not a risk factor for leg, ankle and foot injuries. Conclusions: This review provides limited evidence that hip muscle performance variables are related to leg, ankle and foot injuries. Emerging evidence indicates this might be a result of the injury rather than a contributor to the injury.

Screening the Young Dancer: Summarizing Thirty Years of Screening

The injuries sustained by dance students are mainly the result of overuse (excessive quantity) or abuse (incorrect technique); thus, they could be prevented. The outcome of a dance injury can either affect participation in dance for a given time or bring the student’s potential development as a dancer to an end. In order to predict who is prone to what injuries the medical profession has developed screening processes by which one can draw conclusions for individual dance students regarding their risk factors for certain injuries, and also accumulate data regarding this specific population and establish “norms” and objective parameters to compare between individuals. This chapter will address the differences between specific age groups and describe the correlation between body structure, dance technique, and some pathologies. It should provide tools to empower students and teachers, and enhance medical professionals’ knowledge of the specific issues relevant to dance students.

Influence of textured insoles on dynamic postural balance of young dancers

BACKGROUND Postural balance (PB) is a significant factor in dance performance and injury prevention. We aimed to determine whether the use of textured insoles inserted into casual walking shoes of dancers improved their dynamic PB and whether dancers with previous injury manifested different dynamic PB compared with non-injured dancers. METHODS In this crossover design study, 26 ballet dancers from the Australian Ballet School, aged 14-19 yrs, were divided into two groups matched by sex and class levels. Group 1 wore the textured insoles in their walking shoes for at least 2 hrs/day during weeks 1 to 4 of the study, and group 2 wore the textured insoles in their walking shoes during weeks 5 to 8. Reports from the school medical staff identified dancers who had previous injuries. All participants were tested pre-intervention and at 4 and 8 weeks by an accelerometer for dynamic PB (average acceleration magnitude, root mean square acceleration, range, and mean frequency) during single-leg fondu, flexing and extending of the knee. FINDINGS Interactions (group x time) were found in dynamic PB measured in the mediolateral direction, indicating significant differences between the groups at the three testing times. Furthermore, both previously injured and noninjured dancers manifested significant time effects from pre-intervention to 8 weeks, indicating a significant improvement in their PB after using the textured insoles. CONCLUSION Textured insoles can improve the dynamic PB of ballet dancers and can also be useful as a routine intervention. PB was improved among both dancers with previous injury and non-injured dancers.

Is There a Correlation Between Static and Dynamic Postural Balance Among Young Male and Female Dancers

ABSTRACT Aimed to investigate whether young male and female dancers have different patterns of association between static and dynamic postural balance (PB), 60 dancers from the Australian Ballet School (14–19 years old) were tested for static and dynamic PB with head and lumbar accelerometers. Monotonic relationships between static and dynamic PB were found in head movements among young female dancers in all three directions, but were found for young male dancers in the mediolateral (ML) and anteroposterior (AP) directions only. In lumbar movements, monotonic relationships were found for young female dancers in the AP direction only. Comparing head with lumbar movements in static PB, young male dancers demonstrated monotonic relationships between head and lumbar movements in all 3 directions; however, young female dancers demonstrated monotonic relationships in the AP direction only. In the dynamic measurements, both male and female dancers demonstrated monotonic relationships between head and lumbar movements for all parameters measured in the ML and vertical directions (p < .05). In conclusions, among female dancers static PB ability is correlated with their dynamic ability, whereas among male dancers, no relationship between the static and dynamic PB in the AP direction exists. Male dancers showed head and lumbar coordination in the static PB movement, but both genders manifested no head and lumbar coordination in the AP direction measured for dynamic PB.

Tibial impact accelerations in gait of primary school children: The effect of age and speed

Tibial stress fractures are associated with increased lower extremity loading at initial foot-ground contact, reflected in high peak positive acceleration (>8g) of the tibia in adults. There is no reported data on peak positive acceleration of the tibia in children during walking and running. The aim of this study was to establish tibial peak positive acceleration responses in children across a range of age and gait speeds. Twenty-four children aged 8.5±1.4years with no known gait pathology comprised two age groups; Young (7-9year, n=12) and Older (10-12 years, n=12). Wireless Inertial Measurement Unit comprising a tri-axial accelerometer was securely taped to the anteromedial aspect of the distal tibia to measure peak positive acceleration responses while walking and running on the treadmill at 3 different speeds (20% below baseline, baseline, and 20% above baseline). Results showed significant increase in peak positive acceleration with increased gait speed and greater variability in young children compared to older children. The study suggests that ground impact in walking, but not running, is mature by age 7 years. Future studies should explore strategies using peak positive acceleration responses to monitor ground impact during sport activities and its application in gait retraining.

Biomechanical characteristics of overweight and obese children during five different walking and running velocities

The characterization of activity patterns of overweight and obese (OW) children and adolescents is essential, and should be carried out before they join an exercise training programme and increase their physical activity in order to maintain or reduce body weight. The purpose of this study is to verify whether the biomechanical parameters characterizing frequently used walking and running speeds vary between OW and normal-weight (NW) children. Thirty-one prepubescent OW children (9.9 y ± 1.3) and 10 prepubescent NW children (9.9 y ± 1.2) participated in this study. All participants were evaluated for temporal parameters (e.g. cycle length, cycle time, stance phase time, double support phase time, etc.) and for foot pressure parameters (e.g. contact area, duration of contact, peak pressure, etc.) in six different foot areas, at three walking velocities, and two running velocities. A group effect (p < .05) was found for the peak pressure, duration of contact percentile, maximum force, foot pressure–time integral, cycle length, cycle time, stance phase time, double support phase time, relative stance phase, and relative double support phase, indicating that the OW children manifested significantly higher values compared with the NW children. Assessment of the movement characteristics of OW children indicated an elongation of gait parameters, such as step cycle and support stage, compared to NW children, in different walking and running speeds. These changes suggest that OW children develop different walking/running patterns with increased foot pressure, which may predispose them to foot pain and overuse injuries.