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1.
Ergonomics ; 65(10): 1373-1379, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35084296

RESUMO

Healthcare workers have a high rate of low back injury due to patient handling tasks. These workers receive training in patient handling methods such as adjusting bed height, but often ignore them. In this study, 35 healthcare workers completed patient boosts at a self-chosen bed height and again with the bed in a higher standardised position. Motion capture and force data were collected for analysis. Given the choice, less than half of participants adjusted the bed at all and none of them moved the bed to the highest position (99.1 cm). The self-chosen bed position yielded significantly higher low back force than the higher position at L4-L5 and L5-S1 (p = 0.02, p = 0.01 respectively). Low back forces can be reduced by raising the bed prior to engaging in patient handling tasks, which is a simple step that can reduce forces placed on healthcare workers' low backs. Practitioner summary: Healthcare workers experience high rates of low back pain secondary to patient handling tasks. In this cross-sectional crossover study, healthcare workers consistently chose a low bed height when boosting a patient, which resulted in higher low back loads compared to the highest bed height.


Assuntos
Lesões nas Costas , Movimentação e Reposicionamento de Pacientes , Estudos Cross-Over , Estudos Transversais , Pessoal de Saúde , Humanos , Remoção
2.
J Sports Sci Med ; 21(1): 120-126, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35250341

RESUMO

The abdominal muscles are vital in providing core stability for functional movements during most activities. There is a correlation between side asymmetry of these muscles and dysfunction. Thus, the purpose of this study was to evaluate and compare trunk muscle morphology and trunk rotational strength between sprint hurdlers, an asymmetrical sport, and sprinters, a symmetrical sport. Twenty-one trained collegiate sprint hurdlers and sprinters were recruited for the study (Hurdlers: 4M, 7F; Sprinters: 8M, 2F), average age (years) hurdlers: 20 ± 1.2; sprinters: 20.4 ± 1.9, height (cm) hurdlers: 172.6 ± 10.2; sprinters: 181.7 ± 4.5, and weight (kg) hurdlers: 67.6 ± 12.0; sprinters: 73.9 ± 5.6. Using real-time ultrasound, panoramic images of the internal oblique (IO) and external oblique (EO) were obtained at rest and contracted (flexion and rotation) in a seated position for both right and left sides of the trunk. While wearing a specially crafted shoulder harness, participants performed three maximal voluntary trunk rotational contractions (MVC). The three attempts were then averaged to obtain an overall MVC score for trunk rotation strength. Average MVC trunk rotational strength to the right was greater among all participants, p < 0.001. The IO showed greater and significant thickness changes from resting to contracted state than the EO, this was observed in all participants. The IO side asymmetry was significantly different between groups p < 0.01. Hurdlers, involved in a unilaterally demanding sport, exhibited the expected asymmetry in muscle morphology and in trunk rotational strength. Interestingly, sprinters, although involved in a seemingly symmetrical sport, also exhibited asymmetrical trunk morphology and trunk rotational strength.


Assuntos
Músculos Abdominais , Músculos Abdominais Oblíquos , Músculos Abdominais/diagnóstico por imagem , Músculos Abdominais/fisiologia , Estudos Transversais , Humanos , Músculo Esquelético/fisiologia , Tronco/fisiologia
3.
BMC Musculoskelet Disord ; 22(1): 282, 2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33731070

RESUMO

BACKGROUND: The strength and size of core muscles, including the abdominal muscles, are crucial to proper function in most activities. Therefore, it is important to reliably assess these characteristics. Our primary objective was to determine if the length, thickness and cross-sectional area of the transversus abdominis (TrA) can be visualized independently from the internal and external abdominal oblique muscles using extended field of view ultrasound imaging at rest and with contraction and to establish its intra- and inter-tester reliability. METHODS: Twenty-six individuals were recruited to participate in the study (20 F, 6 M), average age 24.0 years (SD 9.4), height 170.7 cm (SD 8.6) and weight 63.9 kg (SD 9.0). From this total number of participants, two groups of 16 randomly selected participants were assessed to determine intra- and inter-tester reliability respectively. Extended field of view ultrasound images were obtained at three vertebral levels during rest and contraction in the side lying position for both the right and left sides of the trunk. RESULTS: Excellent intra-tester and inter-tester reliability was seen (ICC range of 0.972 to 0.984). The overall average percent standard error of the measurement for all measurements and locations was approximately 4%. The overall average minimal difference for the thickness measurement for the resting and contraction conditions combined were as follows: intratester 0.056 (0.014) cm and intertester 0.054 (0.017) cm, for area intratester 0.287 (0.086) cm2 and intertester 0.289 (0.101) cm2 and for length intratester 0.519 (0.097) cm and intertester 0.507 (0.085) cm. CONCLUSIONS: Extended field of view ultrasound imaging is an effective method of reliably capturing clear images of the TrA during rest and contraction. It provides an efficient mechanism for the analysis of muscle morphology by being able to measure the cross-sectional area, thickness, and length on one image. This methodology is recommended for studies investigating TrA function and training.


Assuntos
Músculos Abdominais , Contração Muscular , Músculos Abdominais/diagnóstico por imagem , Adulto , Humanos , Reprodutibilidade dos Testes , Tronco , Ultrassonografia , Adulto Jovem
4.
J Ultrasound Med ; 39(12): 2305-2312, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32412115

RESUMO

OBJECTIVES: The tibialis posterior (TP) is a vital muscle for controlling the medial longitudinal arch of the foot during weight-bearing activities. Dysfunction of this muscle is associated with a variety of pathologic conditions; thus, it is important to reliably assess its morphologic characteristics. Ultrasound (US) has been used to assess characteristics of TP tendons but not the muscle cross-sectional area (CSA). The purpose of this study was to establish a reliable US technique to measure the TP CSA and thickness. METHODS: Twenty-three healthy volunteers participated. We evaluated the CSA and thickness at 4 measurement locations (anterior and posterior views at both 30% and 50% of the shank length). RESULTS: The participants included 12 female and 11 male volunteers (mean age ± SD, 31.23 ± 14.93 years). Excellent reliability was seen for the CSA and thickness at all locations (intraclass correlation coefficients, 0.988-0.998). Limits of agreement (LoA) and standard errors of the measurement (SEMs) were slightly lower at the 30% locations (LoA at 30%, 4.6-9.2; LoA at 50%, 6.4-9.7; SEM at 30%, 0.03-0.05; SEM at 50%, 0.04-0.07). Strong correlations were seen between anterior and posterior measurements of the CSA (30%, r = 0.99; P < .0001; 50%, r = 0.94; P < .0001) and thickness (30%, r = 0.98; P < .0001; 50%, r = 0.95; P = .0001). CONCLUSIONS: Based on these results, the TP can be measured accurately with US at any of the tested locations. Due to the ease of collection and the quality of the data, we recommend the anterior view at 30% of the shank length to measure the CSA. The ability to assess muscle size of the TP will aid in a variety of medical and research applications.


Assuntos
, Tendões , Feminino , Pé/diagnóstico por imagem , Humanos , Perna (Membro) , Masculino , Reprodutibilidade dos Testes , Tendões/diagnóstico por imagem , Ultrassonografia
5.
J Ultrasound Med ; 39(6): 1107-1116, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31837060

RESUMO

OBJECTIVES: Foot and leg muscle strength and size are crucial to proper function. It is important to assess these characteristics reliably. Our primary objective was to compare the measurement of still images to cine loops. The secondary purpose was to determine interoperator and intraoperator reliability between operators of different experience levels using video clips and internal and external landmarks. METHODS: Twelve healthy volunteers participated in our study. Internal (navicular tuberosity) and external (lateral leg length at 30% and 50% from the knee joint line) landmarks were used. Two operators each captured and later measured still and cine loop images of selected foot and leg muscles. RESULTS: The 12 participants included 8 male and 4 female volunteers (mean age ± SD, 23.5 ± 1.9 years). Good to excellent intraoperator and interoperator reliability was seen (intraclass correlation coefficient range of 0.946-0.998). The use of cine loops improved the intraclass correlation coefficients for both intraoperator and interoperator reliability (0.5%-4% increases). The use of cine loops decreased the intraoperator standard error of the measurement and limits of agreement of the novice operator (decreases of 45%-73% and 24%-51%, respectively), and these became comparable to those of experienced operators using still images. The interoperator standard errors of the measurement dropped by 42% to 53%, whereas the limits of agreement dropped by 27% to 40%. No substantial changes were noted in the tibialis anterior across reliability metrics. CONCLUSIONS: Improved protocols that take advantage of using internal bony landmarks and cine loops during both the image-gathering and measurement processes improve the reliability of research examining muscle size changes in the lower leg or foot associated with muscle changes due to exercise, injury, disuse, or disease.


Assuntos
Competência Clínica/estatística & dados numéricos , Processamento de Imagem Assistida por Computador/métodos , Força Muscular/fisiologia , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia , Ultrassonografia/métodos , Adulto , Feminino , Pé/anatomia & histologia , Pé/fisiologia , Humanos , Perna (Membro)/anatomia & histologia , Perna (Membro)/fisiologia , Masculino , Variações Dependentes do Observador , Valores de Referência , Reprodutibilidade dos Testes , Adulto Jovem
6.
BMC Musculoskelet Disord ; 20(1): 608, 2019 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-31837710

RESUMO

BACKGROUND: Evaluating the strength of the small muscles of the foot may be useful in a variety of clinical applications but is challenging from a methodology standpoint. Previous efforts have focused primarily on the functional movement of toe flexion, but clear methodology guidelines are lacking. A novel foot doming test has also been proposed, but not fully evaluated. The purposes of the present study were to assess the repeatability and comparability of several functional foot strength assessment techniques. METHODS: Forty healthy volunteers were evaluated across two testing days, with a two-week doming motion practice period between them. Seven different measurements were taken using a custom toe flexion dynamometer (seated), custom doming dynamometer (standing), and a pressure mat (standing). Measurements from the doming dynamometer were evaluated for reliability (ICCs) and a learning effect (paired t-tests), while measurements from the toe flexion dynamometer and pressure mat were evaluated for reliability and comparability (correlations). Electromyography was also used to descriptively assess the extent of muscle isolation in all measurements. RESULTS: Doming showed excellent within-session reliability (ICCs > 0.944), but a clear learning effect was present, with strength (p < 0.001) and muscle activity increasing between sessions. Both intrinsic and extrinsic muscles were engaged during this test. All toe flexion tests also showed excellent reliability (ICCs > 0.945). Seated toe flexion tests using the dynamometer were moderately correlated to standing toe flexion tests on a pressure mat (r > 0.54); however, there were some differences in muscle activity. The former may better isolate the toe flexors, while the latter appeared to be more functional for many pathologies. On the pressure mat, reciprocal motion appeared to display slightly greater forces and reliability than isolated toe flexion. CONCLUSIONS: This study further refines potential methodology for foot strength testing. These devices and protocols can be duplicated in the clinic to evaluate and monitor rehabilitation progress in clinical populations associated with foot muscle weakness.


Assuntos
Pé/fisiologia , Dinamômetro de Força Muscular , Força Muscular , Articulação do Dedo do Pé/fisiologia , Adulto , Eletromiografia , Feminino , Voluntários Saudáveis , Humanos , Masculino , Reprodutibilidade dos Testes , Adulto Jovem
7.
Int J Sports Med ; 39(8): 630-635, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29883987

RESUMO

The incidence of low back pain (LBP) among elite ballroom dancers is high and understanding associations between muscle morphology and pain may provide insight into treatment or training options. Research has linked multifidus muscle atrophy to LBP in the general and some athletic populations; however, this has not been examined in ballroom dancers. We compared the lumbar multifidus cross-sectional area (CSA) at rest in 57 elite level ballroom dancers (age 23±2.4 years; height, 174±11 cm; mass, 64±10 kg) divided into one of three pain groups, according to their self-reported symptoms, 1) LBP group (n=19), 2) minimal LBP (n=17), and 3) no LBP (n=21). There were no significant difference in demographics between the groups (P>0.05). The LBP group demonstrated significant differences in reported pain and Oswestry Disability Index scores compared to the other two groups. There was no significant difference between groups in multifidus cross-sectional area (P=0.49). Asymmetry was found in all groups with the overall left side being significantly larger than the right (P<0.002). Pain associated with segmental decrease in multifidus CSA was not observed in ballroom dancers with LBP, suggesting other reasons for persistent LBP in ballroom dancers.


Assuntos
Dança/lesões , Dor Lombar/etiologia , Músculos Paraespinais/anatomia & histologia , Músculos Paraespinais/fisiologia , Músculos Abdominais/diagnóstico por imagem , Índice de Massa Corporal , Dança/fisiologia , Feminino , Humanos , Dor Lombar/patologia , Dor Lombar/fisiopatologia , Masculino , Atrofia Muscular/patologia , Músculos Paraespinais/diagnóstico por imagem , Músculos Paraespinais/patologia , Ultrassonografia , Adulto Jovem
8.
J Strength Cond Res ; 29(5): 1172-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25719919

RESUMO

The assessment of functionality should include parameters that consider postural control, limb asymmetries, range of motion limitations, proprioceptive deficits, and pain. An increasingly popular battery of tests, the Functional Movement Screen (FMS), is purported to assess the above named parameters. The purpose of our study was twofold: (a) to report differences in total FMS scores in children, provide preliminary normative reference values of each of the 7 individual FMS scores for both genders and report on asymmetries and (b) to evaluate the relationship between total FMS scores, age, body mass index (BMI), core strength/stability, and postural angles to explore the possibility of using the FMS in the assessment of children's functional fitness. Descriptive data on 77 children aged 8-11 years were collected. The children performed core strength/stability exercises. Photographs were taken from a lateral view for later calculation of postural angles. The children performed the FMS while being videotaped for later review. The average total FMS score (of 21) was 14.9 (+1.9), and BMI was 16.4 (+2.2). Static posture is not related to results of the FMS. Core strength was positively correlated to the total FMS score (r = 0.31; p = 0.006). Over 60% demonstrated at least 1 asymmetry. The individual test scores indicate that none of the test items is too difficult for the children. Based on the screen's correlation to core strength, and the fact that it identifies areas of asymmetry, we suggest to further investigate its possible use in the assessment of children's functional fitness.


Assuntos
Teste de Esforço , Movimento/fisiologia , Força Muscular/fisiologia , Postura/fisiologia , Índice de Massa Corporal , Criança , Feminino , Humanos , Masculino , Moldávia , Músculos Paraespinais/fisiologia , Reto do Abdome/fisiologia , Valores de Referência
9.
J Sports Sci Med ; 14(3): 643-7, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26336352

RESUMO

The purpose of this study was to examine the effect of minimalist running shoes on oxygen uptake during running before and after a 10-week transition from traditional to minimalist running shoes. Twenty-five recreational runners (no previous experience in minimalist running shoes) participated in submaximal VO2 testing at a self-selected pace while wearing traditional and minimalist running shoes. Ten of the 25 runners gradually transitioned to minimalist running shoes over 10 weeks (experimental group), while the other 15 maintained their typical training regimen (control group). All participants repeated submaximal VO2 testing at the end of 10 weeks. Testing included a 3 minute warm-up, 3 minutes of running in the first pair of shoes, and 3 minutes of running in the second pair of shoes. Shoe order was randomized. Average oxygen uptake was calculated during the last minute of running in each condition. The average change from pre- to post-training for the control group during testing in traditional and minimalist shoes was an improvement of 3.1 ± 15.2% and 2.8 ± 16.2%, respectively. The average change from pre- to post-training for the experimental group during testing in traditional and minimalist shoes was an improvement of 8.4 ± 7.2% and 10.4 ± 6.9%, respectively. Data were analyzed using a 2-way repeated measures ANOVA. There were no significant interaction effects, but the overall improvement in running economy across time (6.15%) was significant (p = 0.015). Running in minimalist running shoes improves running economy in experienced, traditionally shod runners, but not significantly more than when running in traditional running shoes. Improvement in running economy in both groups, regardless of shoe type, may have been due to compliance with training over the 10-week study period and/or familiarity with testing procedures. Key pointsRunning in minimalist footwear did not result in a change in running economy compared to running in traditional footwear prior to 10 weeks of training.Both groups (control and experimental) showed an improvement in running economy in both types of shoes after 10 weeks of training.After transitioning to minimalist running shoes, running economy was not significantly different while running in traditional or minimalist footwear.

10.
J Sports Sci Med ; 13(4): 823-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25435775

RESUMO

In this study we examined how hill running affects the Achilles tendon, a common location for injuries in runners. Twenty females ran for 10 min on each of three randomly ordered grades (-6%, 0 and +6%) at speeds selected to match the metabolic rates. Achilles tendon (AT) cross-sectional area (CSA) was imaged using Doppler ultrasound and peak vertical forces were analyzed using an instrumented treadmill. A metabolic cart and gas analyzer ensured a similar metabolic cost across grades. Data were analyzed using a forward selection regression. Results showed similar decreases in AT CSA from pre- to post-run for all three conditions of ~5 to 7% (p = 0.0001). Active peak vertical forces were different across grades (p = 0.0001) with the largest occurring during downhill running and smallest during uphill running. Since changes in AT CSA were not different between grades, each form of running appears equal and acceptable in regards to how the Achilles tendon reacts. That is, the results suggest that the Achilles tendon is affected by downhill, level, and uphill running and a decrease in CSA appears to be a normal response. Key PointsDownhill (- 6%), level and uphill (+ 6%) running at different speeds each caused a statistically significant decrease in the Achilles tendon cross-sectional area in healthy, trained runners.The magnitude of change in Achilles tendon cross-sectional area did not differ between grades when metabolic cost of running was matched.Downhill running resulted in the largest peak vertical force, while uphill running resulted in the smallest.

11.
PLoS One ; 19(10): e0309157, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39365768

RESUMO

OBJECTIVES: The ability to control landings and stabilize quickly is essential in sports like gymnastics and cheerleading, where landing quality impacts scores. The similarities and contrasts between these sports, where one trains primarily barefoot and the other shod, may increase understanding of the kinetic role of the foot during landings. DESIGN: Sixteen gymnasts (GYM), sixteen cheerleaders (CHR), and sixteen non-athletes (NAT) performed single-foot shod and barefoot drop landings onto a force plate. METHOD: Foot muscle strength was assessed using a custom test and ultrasound imaging was used to measure six foot muscles. Group differences in muscle sizes and strength measurements were compared using one-way ANOVAs (α = 0.05). Landing mechanics metrics were evaluated using 3 x 2 between-within ANOVAs (α = 0.05). Pairwise comparisons were made using Tukey post-hoc tests. RESULTS: Barefoot landings resulted in greater peak vertical ground reaction force (pVGRF) and lower time to pVGRF (TTpVGRF). Significant group main effect differences were found between GYM and NAT for all kinetic measures (GYM: shorter time to stability (TTS) and TTpVGRF, and greater pVGRF), while no significant differences in landing kinetics were found between CHR and either GYM or NAT. No interactions were found between group and condition. GYM and CHR had significantly greater summed foot muscle size than NAT, however, only CHR displayed significantly greater toe flexion force than NAT. CONCLUSIONS: Our data suggests that while wearing shoes does not affect groups differently, footwear reduces initial peak VGRFs but does not influence later stabilization times.


Assuntos
, Ginástica , Músculo Esquelético , Sapatos , Humanos , Pé/fisiologia , Ginástica/fisiologia , Músculo Esquelético/fisiologia , Feminino , Masculino , Fenômenos Biomecânicos , Adulto Jovem , Adolescente , Cinética , Força Muscular/fisiologia , Atletas , Adulto
12.
J Strength Cond Res ; 27(6): 1496-502, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22986445

RESUMO

Maximum running speed and acceleration are essential components in many sports. The identification of specific training protocols to maximize sprint speed would be useful knowledge for coaches and players. The purpose of this study was to determine the effect of a high-speed treadmill (HST) with the use of a body weight support (BWS) system in a 6-week sport acceleration program (SAP) on female soccer athlete's 40-yard sprint time and maximal isometric knee flexor and extensor strength. Two treatment groups and one control group were created. Both treatment groups participated in a 12-session SAP. The first treatment group (n = 12) used a BWS system while running on a HST; the second group (n = 12) used a standard treadmill (ST) with no BWS system. The participants of the control group (n = 8), NT, did not participate in a sports acceleration program and did not alter their exercise routines outside of the study. An analysis of covariance was performed using baseline measures as the covariate. The 40-yard sprint times for both treatment groups were shown to improve significantly compared with the control group (p < 0.001). Isometric knee flexor strength showed a greater increase in the ST group (p = 0.026) than in the other 2 groups, whereas knee extensor strengths did not show significant differences between treatment groups and control group (p > 0.05). Participants in the ST group had a much higher rate (66%) of shin splints and foot pain throughout the study than those in the HST (8%) and NT (0%) groups. These results can help high school coaches and athletes determine the optimal treadmill training regime.


Assuntos
Força Muscular , Educação Física e Treinamento/métodos , Corrida/fisiologia , Futebol/fisiologia , Aceleração , Adolescente , Desempenho Atlético/fisiologia , Feminino , Humanos , Contração Isométrica , Perna (Membro)/fisiologia , Músculo Esquelético/fisiologia
13.
Work ; 75(4): 1351-1359, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36710705

RESUMO

BACKGROUND: Repositioning patients is a frequent task for healthcare workers causing substantial stress to the low back. Patient handling methodologies that reduce low back load should be used. Some studies have observed the effect of bed height on back forces using a limited range of heights. This study details a wider range. OBJECTIVE: The aim of this study was to discover an optimal bed height for reducing low back force when boosting a patient. METHODS: 11 university students and local residents participated by completing a series of boosts with a 91.6 kg research assistant acting as dependent. The bed was adjusted 3% of participant height and 3 boosts were completed at each height which resulted in 8-10 different bed heights depending on the height of the participant. Motion and force data were collected to estimate low back forces via 3DSSPP. Pearson's R was performed to observe the correlation between caregiver height and low back forces. RESULTS: There were significant negative correlations between bed height and low back compression force at L4-L5 (r = -0.676, p = <0.001) and L5-S1 (r = -0.704, p = <0.001). There were no significant correlations with any shear forces. CONCLUSION: The highest bed height led to decreased low back compression forces regardless of participant height, but there was not a significant difference in shear forces. Thus, healthcare workers may experience less low back stress with the bed at a higher height. There may be a force tradeoff between the low back and other parts of the body that needs further exploration. Healthcare workers need to be made aware of the implications of adjusting the environment when performing patient handling tasks.


Assuntos
Movimentação e Reposicionamento de Pacientes , Humanos , Pessoal de Saúde
14.
J Clin Med ; 12(5)2023 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-36902835

RESUMO

There is a broad scope of literature investigating whole-body vibration (WBV) effects on blood flow (BF). However, it is unclear how therapeutic localized vibrations alter BF. Low-frequency massage guns are advertised to enhance muscle recovery, which may be through BF changes; however, studies using these devices are lacking. Thus, the purpose of this study was to determine if popliteal artery BF increases from localized vibration to the calf. Twenty-six healthy, recreationally active university students (fourteen males, twelve females, mean age 22.3 years) participated. Each subject received eight therapeutic conditions randomized on different days with ultrasound blood flow measurements. The eight conditions combined either control, 30 Hz, 38 Hz, or 47 Hz for a duration of 5 or 10 min. BF measurements of mean blood velocity, arterial diameter, volume flow, and heart rate were measured. Using a cell means mixed model, we found that both control conditions resulted in decreased BF and that both 38 Hz and 47 Hz resulted in significant increases in volume flow and mean blood velocity, which remained elevated longer than the BF induced by 30 Hz. This study demonstrates localized vibrations at 38 Hz and 47 Hz significantly increase BF without affecting the heart rate and may support muscle recovery.

15.
J Foot Ankle Res ; 15(1): 16, 2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-35172865

RESUMO

BACKGROUND: Previous research shows kinematic and kinetic coupling between the metatarsophalangeal (MTP) and midtarsal joints during gait. Studying the effects of MTP position as well as foot structure on this coupling may help determine to what extent foot coupling during dynamic and active movement is due to the windlass mechanism. This study's purpose was to investigate the kinematic and kinetic foot coupling during controlled passive, active, and dynamic movements. METHODS: After arch height and flexibility were measured, participants performed four conditions: Seated Passive MTP Extension, Seated Active MTP Extension, Standing Passive MTP Extension, and Standing Active MTP Extension. Next, participants performed three heel raise conditions that manipulated the starting position of the MTP joint: Neutral, Toe Extension, and Toe Flexion. A multisegment foot model was created in Visual 3D and used to calculate ankle, midtarsal, and MTP joint kinematics and kinetics. RESULTS: Kinematic coupling (ratio of midtarsal to MTP angular displacement) was approximately six times greater in Neutral heel raises compared to Seated Passive MTP Extension, suggesting that the windlass only plays a small kinematic role in dynamic tasks. As the starting position of the MTP joint became increasingly extended during heel raises, the amount of negative work at the MTP joint and positive work at the midtarsal joint increased proportionally, while distal-to-hindfoot work remained unchanged. Correlations suggest that there is not a strong relationship between static arch height/flexibility and kinematic foot coupling. CONCLUSIONS: Our results show that there is kinematic and kinetic coupling within the distal foot, but this coupling is attributed only in small measure to the windlass mechanism. Additional sources of coupling include foot muscles and elastic energy storage and return within ligaments and tendons. Furthermore, our results suggest that the plantar aponeurosis does not function as a rigid cable but likely has extensibility that affects the effectiveness of the windlass mechanism. Arch structure did not affect foot coupling, suggesting that static arch height or arch flexibility alone may not be adequate predictors of dynamic foot function.


Assuntos
Articulações do Pé , , Fenômenos Biomecânicos , Pé/fisiologia , Articulações do Pé/fisiologia , Marcha , Humanos , Cinética
16.
BMJ Open Sport Exerc Med ; 8(3): e001343, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36111125

RESUMO

Background: Muscle function may be impaired in people with generalised hypermobility, yet prior studies have primarily focused on muscles within the extremities. We aimed to examine changes in lateral abdominal muscle (transversus abdominis (TrA) and the external (EO) and internal abdominal obliques (IO)) thickness and length during contraction between participants with and without hypermobility. Methods: This cross-sectional study examined 12 participants with hypermobility and 12 age-matched, sex-matched, height-matched and weight-matched participants without hypermobility. The Beighton and Belavy-Owen-Mitchell score assessed systemic hypermobility. Muscle thickness and length were measured via panoramic ultrasound scans at rest and during contraction. Results: When compared with rest across all lumbar levels (L1-L5), contraction produced a lesser increase in TrA thickness (ß=0.03, p=0.034) for participants with hypermobility compared with control. No group-by-condition interaction was observed for TrA length across all lumbar levels (L1-L5; p=0.269). Contraction produced a greater decrease in EO thickness (ß=0.08, p=0.002) at L3 only for participants with hypermobility compared with control. No group-by-condition interactions were observed for IO thickness. Conclusion: Participants with hypermobility had partially impaired lateral abdominal muscle function given a lesser ability to increase TrA muscle thickness during contraction compared with controls.

17.
BMJ Open Sport Exerc Med ; 8(1): e001292, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35414957

RESUMO

Objectives: To assess the validity and reliability of ultrasound-derived interbony landmark distances as a proxy for MRI-derived intervertebral disc (IVD) height. Methods: This is a cross-sectional criterion validity study. Twelve college-aged participants without current low back pain completed both MRI and ultrasound imaging of the lumbar spine in a prone position. Single-segment and multisegment distances between the spinous and mammillary processes at the lumbar segments (L2/L3, L3/L4, L4/L5) were measured twice using ultrasound and analysed digitally. Sagittal slices of the lumbar spine were taken via T1-weighted MRI and IVD height, and the overall distance between IVDs L2/L3 and L4/L5 was imaged once and measured twice. Results: There was moderate correlation between multilevel-based measurements (overall distance between L2 and L5, r=0.677, p=0.016) and the average across three levels (r=0.596, p=0.041) when using the spinous processes as bony landmarks. Single-segment measures were not significantly correlated (all: p>0.092). Accuracy and precision were better for the overall MRI-derived distance between the three IVDs from L2 and L5 MRI and the distance measured between the spinous processes L2-L5. There was excellent reliability within multiple measurements at each location, with intraclass correlation coefficient, ICC(3,1), ranging from 0.93 to 0.99 (95% CI 0.82 to 0.99) for ultrasound and from 0.98 to 0.99 (95% CI 0.92 to 0.99) for MRI. Conclusion: Findings do not support the use of ultrasound imaging for estimating single-segment IVD height, yet it may be used to measure the change in distance over time with a certain degree of precision based on its excellent reliability.

18.
PLoS One ; 16(2): e0246605, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33544773

RESUMO

CONTEXT: Obesity is a growing global health concern. The increased body mass and altered mass distribution associated with obesity may be related to increases in plantar shear that putatively leads to physical functional deficits. Therefore, measurement of plantar shear may provide unique insights on the effects of body mass and body distribution on physical function or performance. PURPOSE: 1) To investigate the effects of body mass and distribution on plantar shear. 2) To examine how altered plantar shear influences postural control and gait kinetics. HYPOTHESIS: 1) a weighted vest forward distributed (FV) would shift the center of pressure (CoP) location forward during standing compared with a weighted vest evenly distributed (EV), 2) FV would increase plantar shear spreading forces more than EV during standing, 3) FV would increase postural sway during standing while EV would not, and 4) FV would elicit greater compensatory changes during walking than EV. METHODS: Twenty healthy young males participated in four different tests: 1) static test (for measuring plantar shear and CoP location without acceleration, 2) bilateral-foot standing postural control test, 3) single-foot standing postural test, and 4) walking test. All tests were executed in three different weight conditions: 1) unweighted (NV), 2) EV with 20% added body mass, and 3) FV, also with 20% added body mass. Plantar shear stresses were measured using a pressure/shear device, and several shear and postural control metrics were extracted. Repeated measures ANOVAs with Holms post hoc test were used to compare each metric among the three conditions (α = 0.05). RESULTS: FV and EV increased both AP and ML plantar shear forces compared to NV. FV shifted CoP forward in single-foot trials. FV and EV showed decreased CoP range and velocity and increased Time-to-Boundary (TTB) during postural control compared to NV. EV and FV showed increased breaking impulse and propulsive impulse compared to NV. In addition, EV showed even greater impulses than FV. While EV increased ML plantar shear spreading force, FV increased AP plantar shear spreading force during walking. CONCLUSION: Added body mass increases plantar shear spreading forces. Body mass distribution had greater effects during dynamic tasks. In addition, healthy young individuals seem to quickly adapt to external stimuli to control postural stability. However, as this is a first step study, follow-up studies are necessary to further support the clinical role of plantar shear in other populations such as elderly and individuals with obesity or diabetes.


Assuntos
Índice de Massa Corporal , Pé/fisiologia , Marcha/fisiologia , Adulto , Pé/fisiopatologia , Humanos , Masculino , Obesidade/fisiopatologia , Equilíbrio Postural/fisiologia , Posição Ortostática , Caminhada/fisiologia , Adulto Jovem
19.
J Bodyw Mov Ther ; 28: 264-270, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34776151

RESUMO

OBJECTIVE: To determine if positional release therapy (PRT) or therapeutic massage (TM) was more effective in the treatment of trigger and tender points in the upper trapezius muscle. BACKGROUND: Trigger points in the upper trapezius muscle are common and can be painful. Trigger points are commonly treated using TM however, PRT is a novel treatment that deserves further investigation. METHODS: Sixty healthy male (24) and female (36) participants, (age = 27.1 ± 8.8 years, wt = 75.2 ± 17.9 kg, ht = 172.8 ± 9.7 cm) presenting with upper trapezius pain and a trigger point were recruited and randomized into either the TM or PRT group. Upper trapezius trigger points were found via palpation. Pain level was evaluated using a visual analog scale (VAS) and pain pressure threshold (PPT) was assessed using a pressure algometer. Muscle thickness was measured by B-mode ultrasound, while muscle stiffness was measured by shear-wave elastography (SWE). Participants were measured at baseline, posttreatment and again 48 h later. RESULTS: Both treatments were effective in treatment of pain and muscle stiffness. Although no statistical group differences existed, treatment using PRT showed decreased pain averages and decreased pressure sensitivity at both post treatment, and 48 h later. Neither treatment was able to maintain the reduced muscle stiffness at the 48-h measure in males. CONCLUSION: Both treatments showed a significant ability to reduce pain and acutely decrease muscle stiffness. Although not statistically different, clinically PRT is more effective at decreasing pain, and decreasing pressure sensitivity. Neither treatment method produced a long lasting effect on muscle stiffness in males.


Assuntos
Síndromes da Dor Miofascial , Músculos Superficiais do Dorso , Adolescente , Adulto , Feminino , Humanos , Masculino , Massagem , Síndromes da Dor Miofascial/terapia , Medição da Dor , Limiar da Dor , Pontos-Gatilho , Adulto Jovem
20.
Phys Ther Sport ; 47: 114-119, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33249366

RESUMO

AIMS: To examine single bout and season long Achilles tendon cross-sectional area (CSA) changes before and after running during the early and late cross-country season. DESIGN: OBSERVATIONAL: repeated measures design study. SETTING: Controlled laboratory setting. PARTICIPANTS: This study consisted of 35 participants. The running group included 11 males and 9 females, the control group was 8 males and 7 females. MAIN OUTCOME MEASURES: Diagnostic ultrasound images were taken before and after runners completed a common recovery run during the early and late cross-country season. Ultrasound images of control participants, who did not run, were taken following an averaged time that athletes spent running. RESULTS: No significant tendon season long CSA increases occurred for runners (p = 0.453). Runners experienced significant Achilles tendon CSA decreases compared within subjects (p < 0.05) and between controls (p < 0.05). Significant CSA decreases occurred for runners during the early and late season run (p < 0.05) with greater percentages of decrease in the early season (p = 0.009). Male and female runners experienced similar CSA decreases while running (p = 0.696). CONCLUSIONS: No Achilles tendon CSA increases occurred over the season. Significant Achilles tendon CSA decreases occurred while running during early and late season runs, but varied with larger CSA decreases occurring during the early season.


Assuntos
Tendão do Calcâneo/anatomia & histologia , Tendão do Calcâneo/fisiologia , Adaptação Fisiológica , Comportamento Competitivo/fisiologia , Corrida/fisiologia , Tendão do Calcâneo/diagnóstico por imagem , Tendão do Calcâneo/lesões , Adulto , Feminino , Humanos , Masculino , Estações do Ano , Ultrassonografia , Universidades , Adulto Jovem
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