Strength training results in changes in skeletal muscle; however, changes in the central nervous system also occur. Over the last 15 years, non‐invasive brain stimulation techniques, such as ...transcranial magnetic stimulation, have been used to study the neural adaptations to strength training. This review explored the hypothesis that the neural adaptations to strength training may be due to changes in corticospinal excitability and inhibition and, such changes, contribute to the gain in strength following strength training. A systematic review, according to PRISMA guidelines, identified studies by database searching, hand‐searching and citation tracking between January 1990 and the first week of February 2017. Methodological quality of included studies was determined using the Downs and Black quality index. Data were synthesised and interpreted from meta‐analysis. Nineteen studies investigating the corticospinal responses following strength training were included. Meta‐analysis found that strength training increased strength standardised mean difference (SMD) 0.84, 95% CI 0.55 to 1.13, decreased short‐interval intracortical inhibition (SMD −1.00, 95% CI −1.84 to −0.17) and decreased the cortical silent period (SMD −0.66, 95% CI −1.00 to −0.32). Strength training had no effect on motor threshold (SMD −0.12, 95% CI −0.49 to 0.25), but a borderline effect for increased corticospinal excitability (SMD 0.27, 95% CI 0.00 to 0.54). In untrained healthy participants, the corticospinal response to strength training is characterised by reduced intracortical inhibition and cortical silent period duration, rather than changes in corticospinal excitability. These data demonstrate that strength training targets intracortical inhibitory networks within the primary motor cortex (M1) and corticospinal pathway, characterising an important neural adaptation to strength training.
It is now well established the adaptations within the nervous system contribute to strength development during the early phases of strength training; however, the underlying neural mechanisms remain elusive. This study establishes that the corticospinal response to strength training is characterised by reduced intracortical inhibition and cortical silent period duration, rather than increased corticospinal excitability, which suggest strength training targets intracortical inhibitory neurons.
Running participation continues to increase. The ideal strike pattern during running is a controversial topic. Many coaches and therapists promote non-rearfoot strike (NRFS) running with a belief ...that it can treat and prevent injury, and improve running economy.
The aims of this review were to synthesise the evidence comparing NRFS with rearfoot strike (RFS) running patterns in relation to injury and running economy (primary aim), and biomechanics (secondary aim).
Systematic review and meta-analysis. Consideration was given to within participant, between participant, retrospective, and prospective study designs.
MEDLINE, EMBASE, CINAHL, and SPORTDiscus.
Fifty-three studies were included. Limited evidence indicated that NRFS running is retrospectively associated with lower reported rates of mild (standard mean difference (SMD), 95% CI 3.25, 2.37-4.12), moderate (3.65, 2.71-4.59) and severe (0.93, 0.32-1.55) repetitive stress injury. Studies prospectively comparing injury risk between strike patterns are lacking. Limited evidence indicated that running economy did not differ between habitual RFS and habitual NRFS runners at slow (10.8-11.0 km/h), moderate (12.6-13.5 km/h), and fast (14.0-15.0 km/h) speeds, and was reduced in the immediate term when an NRFS-running pattern was imposed on habitual RFS runners at slow (10.8 km/h; SMD = - 1.67, - 2.82 to - 0.52) and moderate (12.6 km/h; - 1.26, - 2.42 to - 0.10) speeds. Key biomechanical findings, consistently including both comparison between habitual strike patterns and following immediate transition from RFS to NRFS running, indicated that NRFS running was associated with lower average and peak vertical loading rate (limited-moderate evidence; SMDs = 0.72-2.15); lower knee flexion range of motion (moderate-strong evidence; SMDs = 0.76-0.88); reduced patellofemoral joint stress (limited evidence; SMDs = 0.63-0.68); and greater peak internal ankle plantar flexor moment (limited evidence; SMDs = 0.73-1.33).
The relationship between strike pattern and injury risk could not be determined, as current evidence is limited to retrospective findings. Considering the lack of evidence to support any improvements in running economy, combined with the associated shift in loading profile (i.e., greater ankle and plantarflexor loading) found in this review, changing strike pattern cannot be recommended for an uninjured RFS runner.
CRD42015024523.
Objective
To provide a narrative synthesis of the research literature pertaining to footwear comfort, including definitions, measurement scales, footwear design features, and physiological and ...psychological factors.
Methods
A systematic search was conducted which yielded 101 manuscripts. The most relevant manuscripts were selected based on the predetermined subheadings of the review (definitions, measurement scales, footwear design features, and physiological and psychological factors). A narrative synthesis of the findings of the included studies was undertaken.
Results
The available evidence is highly fragmented and incorporates a wide range of study designs, participants, and assessment approaches, making it challenging to draw strong conclusions or implications for clinical practice. However, it can be broadly concluded that (i) simple visual analog scales may provide a reliable overall assessment of comfort, (ii) well‐fitted, lightweight shoes with soft midsoles and curved rocker‐soles are generally perceived to be most comfortable, and (iii) the influence of sole flexibility, shoe microclimate and insoles is less clear and likely to be more specific to the population, setting and task being performed.
Conclusion
Footwear comfort is a complex and multifaceted concept that is influenced not only by structural and functional aspects of shoe design, but also task requirements and anatomical and physiological differences between individuals. Further research is required to delineate the contribution of specific shoe features more clearly, and to better understand the interaction between footwear features and individual physiological attributes.
Repetitive impacts during running are associated with some running injuries. Tibial acceleration is a proxy for tibial loading, and interventions that can decrease it are likely to be of interest to ...the running community.
What effect do running gait cues have on peak vertical tibial acceleration at a comfortable and moderate running pace, and how will these cues be executed?
Twenty-seven participants ran on a treadmill according to the following cues in random order: run softly and lightly, run with shorter steps, and increase preferred step rate by 7.5 %. Participants maintained each condition for one minute before returning to their 'preferred' running pattern for two minutes. Two tibia-mounted inertial measurement unit sensors were used to collect tibial acceleration data at a 'comfortable' and 'moderate' run pace. A repeated measures analysis of variance test was used to compare the means between running conditions.
Compared to preferred running, the decrease step length (-8 %, p = 0.002, Cohen's d=0.33) and run softly and lightly (-9 %, p = 0.040, Cohen's d=0.38) cues provided a significant reduction in peak vertical tibial acceleration during a comfortable run pace. No significant difference was observed with an increase in step rate. Compared to preferred running, there was no significant difference in peak vertical tibial acceleration with any of the running gait cues during a moderate run pace.
Instructing runners to decrease step length or run softly and lightly can result in small reductions in peak vertical tibial acceleration during a comfortable run pace, but running gait cues during a moderate run pace provide no effects. Differences in the execution of each cue are likely to influence overall tibial loading throughout the stride cycle. These findings provide novel biomechanical evidence for the potential effects of running retraining strategies for reducing tibial accelerations at different running paces.
To investigate the evidence relating to the effectiveness of foot orthoses and shock-absorbing insoles for the prevention of musculoskeletal injury.
Systematic review and meta-analysis.
Clinical ...trials evaluating the effectiveness of foot orthoses and shock-absorbing insoles for the prevention of injury.
Cochrane Library, CINAHL, EMBASE, MEDLINE and SPORTDiscus from their inception up to the first week of June 2016.
11 trials that had evaluated foot orthoses and 7 trials that had evaluated shock-absorbing insoles were included. The median Physiotherapy Evidence Database (PEDro) score for trials that had evaluated foot orthoses and shock-absorbing insoles was 5 (range 3-8/10) and 3 (range 1-7/10), respectively. Meta-analysis found that foot orthoses were effective for preventing overall injuries (risk ratio (RR) 0.72, 95% CI 0.55 to 0.94) and stress fractures (RR 0.59, 95% CI 0.45 to 0.76), but not soft-tissue injuries (RR 0.79, 95% CI 0.55 to 1.14). In contrast, shock-absorbing insoles were not effective for preventing overall injuries (RR 0.92, 95% CI 0.73 to 1.16), stress fractures (RR 1.15, 95% CI 0.57 to 2.32) or soft-tissue injuries (RR 0.92, 95% CI 0.74 to 1.15).
Foot orthoses were found to be effective for preventing overall injuries and stress fractures but not soft-tissue injuries, while shock-absorbing insoles were not found to be effective for preventing any injury. However, further well-designed trials will assist the accuracy and precision of the estimates of risk reduction as the quality of the included trials varied greatly.
•The temperature sensor provided accurate data on adherence to wearing foot orthoses.•Adherence data were not influenced by ambient temperature or physical activity.•The sensor may be useful for ...assessing adherence in clinical practice and research.
The objective of this study was to evaluate the validity of a temperature sensor for the measurement of adherence to wearing foot orthoses. Ten participants were provided with foot orthoses containing an embedded temperature sensor and wore the orthoses for a randomly-determined duration over a five-day period. Sensor-detected wear time was compared to a reference standard (objectively measured wear time using a smart-phone application). Ambient temperature and physical activity were recorded with a temperature gauge and wearable activity tracker, respectively. A simple peak detection algorithm which identified the largest one-minute changes in sensor temperature provided highly accurate wear time values (r = 0.999, coefficient of variation=0.2%). Ambient temperature and physical activity did not significantly influence temperature sensor scores. These findings demonstrate that the temperature sensor provides accurate foot orthosis wear time data and may therefore be a useful tool for documenting adherence in clinical practice and intervention studies.
Background
Little is known about factors that influence footwear selection by field hockey players.
Methods
An online survey was used to collect data on participant demographics and physical ...characteristics, factors influencing footwear selection, perceptions regarding footwear design features on injury and performance, and experiences regarding usability. Nominal and ordinal data were described as absolute frequencies and relative frequencies. Free text responses were analysed using content analysis. Sex‐related differences in quantitative and qualitative data were explored.
Results
A total of 401 hockey players completed the survey. Participants reported that fit, comfort, support, and cushioning were the most important factors when selecting hockey footwear. Most hockey players believed that stud design could influence athletic performance (65%) and injury risk (63%) but reported having no preference on outsole design or stud shape. Most participants (63%) used hockey‐specific footwear, but 46% of female hockey players did not, with 40% using trail running footwear instead. Qualitative analysis revealed that hockey players, particularly female participants, encounter difficulties finding properly fitting footwear. They desire more options for wide or narrow feet and face challenges in accessing suitable hockey shoes due to limited choices and availability.
Conclusions
With over a third of field hockey players not using hockey‐specific footwear, future research should attempt to understand the reasons and assess the impact of different footwear features on comfort, performance, injury risk, and usability.
Background
Foot and ankle pain is common, and generally viewed through a biomedical lens rather than applying a biopsychosocial model. The objectives of this review were to evaluate: (1) the ...psychosocial characteristics of participants with foot/ankle pain compared to participants without foot/ankle pain; (2) the association between psychosocial factors with pain and function in people with foot/ankle pain; and (3) understand the psychosocial factors associated with the lived experience of foot/ankle pain.
Methods
A mixed methods systematic review was conducted according to the PRISMA guidelines and guided by the Joanna Briggs Institute methodology for mixed methods systematic reviews. The databases MEDLINE, Embase, CINAHL, SPORTDiscus, PsychInfo, and Scopus were searched. The Mixed Methods Assessment Tool was used to evaluate study quality. A convergent segregated approach was used to synthesise and integrate quantitative and qualitative data.
Results
Eighteen studies were included, consisting of 13 quantitative, 4 qualitative and 1 mixed methods study. The overall quality of the studies was considered high. Integration of the quantitative and qualitative data were not possible due to the disparate nature of the included studies. A narrative synthesis of the quantitative data revealed that negative emotional and cognitive factors were more common in people with foot/ankle pain compared to those without foot/ankle pain. A significant association was also found between emotional distress with foot pain and foot function in some people with plantar heel pain. In addition, kinesiophobia and pain catastrophising were significantly associated with impaired foot function, and pain catastrophising was significantly associated with first step pain in people with plantar heel pain. The qualitative data revealed emotional impacts, physical challenges, and a loss of self which was individual and unpredictable.
Conclusions
This review provides evidence that negative psychological constructs are greater in participants with foot/ankle pain compared to those without foot/ankle pain, although the cross‐sectional nature of the study designs included in this review reduces the certainty of the evidence. These findings indicate that psychological constructs are associated with foot/ankle pain. Further research should evaluate the predictive ability of multidimensional screening tools to identify patients at risk of developing persistent foot/ankle pain.
Corticosteroid injection is frequently used for plantar heel pain (plantar fasciitis), although there is limited high-quality evidence to support this treatment. Therefore, this study reviewed ...randomised trials to estimate the effectiveness of corticosteroid injection for plantar heel pain.
A systematic review and meta-analysis of randomised trials that compared corticosteroid injection to any comparator. Primary outcomes were pain and function, categorised as short (0 to 6 weeks), medium (7 to 12 weeks) or longer term (13 to 52 weeks).
A total of 47 trials (2989 participants) were included. For reducing pain in the short term, corticosteroid injection was more effective than autologous blood injection (SMD -0.56; 95% CI, - 0.86 to - 0.26) and foot orthoses (SMD -0.91; 95% CI, - 1.69 to - 0.13). There were no significant findings in the medium term. In the longer term, corticosteroid injection was less effective than dry needling (SMD 1.45; 95% CI, 0.70 to 2.19) and platelet-rich plasma injection (SMD 0.61; 95% CI, 0.16 to 1.06). Notably, corticosteroid injection was found to have similar effectiveness to placebo injection for reducing pain in the short (SMD -0.98; 95% CI, - 2.06, 0.11) and medium terms (SMD -0.86; 95% CI, - 1.90 to 0.19). For improving function, corticosteroid injection was more effective than physical therapy in the short term (SMD -0.69; 95% CI, - 1.31 to - 0.07). When trials considered to have high risk of bias were excluded, there were no significant findings.
Based on the findings of this review, corticosteroid injection is more effective than some comparators for the reduction of pain and the improvement of function in people with plantar heel pain. However, corticosteroid injection is not more effective than placebo injection for reducing pain or improving function. Further trials that are of low risk of bias will strengthen this evidence.
PROSPERO registration number CRD42016053216 .
Background
The effect of different orthotic materials on plantar pressures has not been systematically investigated. This study aimed to review and summarise the findings from studies that have ...evaluated the effect of orthotic materials on plantar pressures.
Methods
We conducted a systematic review of experimental studies that evaluated the effect of foot orthotic materials or shoe insole materials on plantar pressures using in‐shoe testing during walking. The following databases were searched: MEDLINE, CINAHL, Embase and SPORTDiscus. Included studies were assessed for methodological quality using a modified Quality Index. Peak pressure, pressure‐time integral, maximum force, force‐time integral, contact area, and contact time were variables of interest. Data were synthesised descriptively as studies were not sufficiently homogeneous to conduct meta‐analysis. Standardised mean differences (Cohen's d) were calculated to provide the size of the effect between materials found in each study.
Results
Five studies were identified as meeting the eligibility criteria. All five studies were laboratory‐based and used a repeated measures design. The quality of the studies varied with scores ranging between 20 and 23 on the modified Quality Index (maximum index score 28). The included studies investigated the effects of polyurethane (including PORON®), polyethylene (including Plastazote®), ethyl vinyl acetate (EVA) and carbon graphite on plantar pressures. Polyurethane (including PORON®), polyethylene (including Plastazote®) and EVA were all found to reduce peak pressure.
Conclusion
Based on the limited evidence supplied from the five studies included in this review, some orthotic materials can reduce plantar pressures during walking. Polyurethane (including PORON®), polyethylene (including Plastazote®) and EVA reduce peak pressure beneath varying regions of the foot. Future well‐designed studies will strengthen this evidence.
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