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1.
Foot (Edinb) ; 55: 102024, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36966048
2.
Eur J Orthop Surg Traumatol ; 32(8): 1535-1541, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34595550

RESUMEN

PURPOSE: The pronator quadratus (PQ) is reflected in the surgical approach to the distal radius. This study explores the functional strength of PQ, 12 months after volar plating without repair of PQ. METHODS: A total of 135 patients were identified from our prospectively collected database. All volunteers had grip strength and pronation power tested in the treated and contralateral forearms at 45, 90 and 135 degrees of elbow flexion using a custom-built torque measuring device and hydraulic hand dynamometer to evaluate forearm pronation. RESULTS: Twenty-seven participants were included in the study. No significant difference was identified in mean peak pronation torque between the volar plated and non-treated forearms. Pronation strength was identified as being independent of angle of elbow flexion. Grip strength was correlated with forearm pronation showing no significant difference between groups. CONCLUSIONS: Our results suggest adequate long-term (15-32 months) functional recovery of the pronator quadratus after volar plating. LEVEL OF EVIDENCE: III.


Asunto(s)
Antebrazo , Fracturas del Radio , Humanos , Antebrazo/cirugía , Fijación Interna de Fracturas/métodos , Placas Óseas , Pronación , Músculo Esquelético , Fracturas del Radio/cirugía
3.
Ergonomics ; 65(7): 987-998, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34842063

RESUMEN

This study aimed to provide a comprehensive assessment of upper limb kinetics and kinematics and shoulder movements during wheelchair propulsion while negotiating a speed bump of 6 cm height using four different wheelchair configurations. 16 healthy males aged 30.8 ± 5.7 years participated in the experiment. The kinetic and kinematic data during wheelchair propulsion were recorded. A smart system was used to collect the push forces and a motion capture system was used to collect upper limb movements. The results show that approximately 50% more pushing force was required to negotiate the speed bump than that of level ground propulsion. At the upward-forward axle position, peak total forces were 95.17 ± 5.70 N which resulted in significantly improved propulsion ergonomics, but 129.36 ± 6.68 N was required at the upward-back axle position at the speed bump push. The findings could help manufactures to design protective gloves for wheelchair users and provide useful rehabilitation information to clinicians and patients. Practitioner summary: This study investigated pushing forces and movements during wheelchair propulsion over a speed bump. Approximately 50% more pushing force was required to negotiate the bump than a level surface propulsion. The upper-forward axle position was found to be reasonably better than other positions during wheelchair propulsion. Abbreviations: UF: upper and forward position; UB: upper and back position; DF: down and forward position; DB: down and back position; ROM: range of motion.


Asunto(s)
Silla de Ruedas , Fenómenos Biomecánicos , Humanos , Cinética , Masculino , Negociación , Hombro , Extremidad Superior
4.
Foot Ankle Int ; 42(9): 1144-1152, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34041931

RESUMEN

BACKGROUND: Despite advancements in operative techniques and the extraordinary number of procedures described for correcting hallux valgus (HV), there is still uncertainty as to why some patients thrive postoperatively whereas others do not. This study aimed to investigate whether the postoperative outcome of HV surgery could be predicted from patient demographics or functional impairment at the time of referral. METHODS: The prospectively collected data, from 92 patients, were analyzed to determine whether patient demographics significantly influenced outcome 52 weeks after surgery. Potential relationships between socioeconomic deprivation and the outcome, as well as between preoperative functional impairment and postoperative improvement, were examined. The Manchester Oxford Foot Questionnaire (MOXFQ) and Scottish Index of Multiple Deprivation (SIMD) were used in this evaluation. RESULTS: None of the demographics studied were found to be statistically significant determinants of outcome. Preoperative MOXFQ scores for patients from the most deprived areas were significantly worse at the time of referral. Patients living in the least deprived postcodes experienced the lowest improvement in MOXFQ scores. Patients from the most deprived SIMD quintile achieved significantly higher improvement in MOXFQ-walking and standing compared to those from the least deprived quintile. A strong positive correlation was found between the preoperative MOXFQ scores and the improvement in the scores postoperatively. CONCLUSION: In this patient cohort, demographics could not be used to predict the postoperative outcome at week 52. Socioeconomic disparities seem to influence the timing of patients seeking surgery. Lower preoperative MOXFQ scores strongly correlate with a lesser degree of postoperative improvement. LEVEL OF EVIDENCE: Level III, retrospective study with prospective arm.


Asunto(s)
Juanete , Hallux Valgus , Hallux Valgus/cirugía , Humanos , Estudios Prospectivos , Estudios Retrospectivos , Encuestas y Cuestionarios , Resultado del Tratamiento
5.
J Biomech ; 122: 110454, 2021 06 09.
Artículo en Inglés | MEDLINE | ID: mdl-33901934

RESUMEN

Shoulder replacement is indicated in the treatment of pain due to osteoarthritis. Few studies have objectively assessed range of motion (RoM) gains at different post-operative time points. This is a prospective 3D motion analysis study to objectively quantify RoM changes at multiple time points following shoulder resurfacing arthroplasty (SRA) for primary gleno-humeral osteoarthritis, comparing it with clinically measured RoM. Clinical assessment, Visual Analog Scale (VAS) pain score, Constant-Morley (CS) and Oxford Shoulder Score (OSS) were recorded. Motion analysis was performed for RoM and three activities of daily living tasks (ADL), pre-operatively and post-operatively at 4 and 12 months. Nineteen shoulders in fifteen patients were included. The mean age was 72 years (range 52-84). There were significant improvements in external and internal rotation, ability to place the hand behind the head and reach the fifth lumbar vertebra, at 4 months on clinical examination and kinematic analysis with no further improvements at 12 months. There was significant improvement in abduction at 4 months with further improvement at 12 months, which was significantly more than noted on clinical assessment. In contrast, kinematic analysis showed a reduction in flexion between 4 and 12 months, while clinically there appeared to be an improvement between these time periods. This is the first study to prospectively utilise objective kinematic 3-D motion analysis in addition to clinical measurements and outcome scores, to investigate the outcome of resurfacing arthroplasty at multiple time points after surgery, providing an understanding into the trends of change in these parameters.


Asunto(s)
Artroplastía de Reemplazo de Hombro , Hemiartroplastia , Articulación del Hombro , Actividades Cotidianas , Anciano , Anciano de 80 o más Años , Fenómenos Biomecánicos , Humanos , Persona de Mediana Edad , Estudios Prospectivos , Rango del Movimiento Articular , Hombro , Articulación del Hombro/cirugía , Resultado del Tratamiento
6.
J Orthop Surg Res ; 15(1): 186, 2020 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-32448307

RESUMEN

BACKGROUND: Although it is known that diabetes interferes with fracture healing, the mechanisms remain poorly understood. The aim of this study was to investigate the correlation of BMP-6 and BMP-9 with the impairment in fracture healing in diabetes, by analyses of the difference in size and calcification of the callus, mechanical endurance, and expressing BMP-6 and BMP-9 in the callus, using a clinical related diabetic rodent model. METHODS: We evaluated femur fracture healing by quantification of size and calcification of the callus by X-ray, histological and histochemical images, loading capacity of the fractured bone, and amount of BMP-6 in the callus and the bones using Western blot assay. RESULTS: Significant upregulation of BMP-6 in the callus and the fractured bones of both non-diabetic and the diabetic animals was observed, at the end of the second and the fourth weeks after fracture. However, significantly lower levels of BMP-6 at 35 kDa with smaller sizes of calcified callus and poor loading capacity of the healing bones were detected in the diabetic animals, compared to the non-diabetic controls. The impairment of the maturation procedure of BMP-6 (35 kDa) from precursors may be underlying the downregulation of the BMP-6 in diabetic animals. CONCLUSIONS: It could be concluded that the delayed fracture healing in the diabetic animals is correlated with deficiency of BMP-6 (35 kDa), which may be caused by impairment of maturation procedure of BMP-6 from precursors to functioning format. This is a primary study but an important step to explore the molecular pathogenesis of impairment of fracture healing in diabetes and to molecular therapeutic approach for the impairment of fracture healing.


Asunto(s)
Proteína Morfogenética Ósea 6/metabolismo , Diabetes Mellitus Experimental/metabolismo , Fracturas del Fémur/metabolismo , Curación de Fractura/fisiología , Animales , Diabetes Mellitus Experimental/diagnóstico por imagen , Fracturas del Fémur/diagnóstico por imagen , Masculino , Ratas , Ratas Sprague-Dawley
8.
BMJ Open Sport Exerc Med ; 6(1): e000604, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32095264

RESUMEN

BACKGROUND: Lateral ankle sprain is one of the most common musculoskeletal injuries, particularly among the sporting population. Due to such prevalence, many interventions have been tried to prevent initial, or further, ankle sprains. Current research shows that the use of traditional athletic tape can reduce the incidence of sprain recurrence, but this may be at a cost to athletic performance through restriction of motion. Kinesiology tape, which has become increasingly popular, is elastic in nature, and it is proposed by the manufacturers that it can correct ligament damage. Kinesiology tape, therefore, may be able to improve stability and reduce ankle sprain occurrence while overcoming the problems of traditional tape. AIM: To assess the effect of kinesiology tape on ankle stability. METHODS: 27 healthy individuals were recruited, and electromyography (EMG) measurements were recorded from the peroneus longus and tibialis anterior muscles. Recordings were taken from the muscles of the dominant leg during induced sudden ankle inversion perturbations using a custom-made tilting platform system. This was performed with and without using kinesiology tape and shoes, creating four different test conditions: barefoot(without tape), shoe(without tape), barefoot(with tape) and shoe(with tape). For each test condition, the peak muscle activity, average muscle activity and the muscle latency were calculated. RESULTS: No significant difference (p>0.05) was found by using the kinesiology tape on any of the measured variables while the wearing of shoes significantly increased all the variables. CONCLUSION: Kinesiology tape has no effect on ankle stability and is unable to nullify the detrimental effects that shoes appear to have.

9.
BMJ Open Sport Exerc Med ; 6(1): e000610, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32095265

RESUMEN

OBJECTIVES: This study aimed to determine whether looped resistance bands affect knee kinematics and lower body muscle activation during the barbell back squat. METHODS: Twenty-six healthy participants (13 female, 13 male) calculated their one repetition maximum (RM) prior to data collection. Each participant performed three squats at both 80% and 40% 1RM wearing a light resistance band, an extra-heavy resistance band and no resistance band.Vicon 3D motion analysis cameras were used to collect the kinematic data, and Delsys Trigno Lab wireless electromyography (EMG) system was used to measure vastus medialis, vastus lateralis, gluteus maximus, gluteus medius and biceps femoris muscle activity. Peak knee flexion angle, peak knee valgus angle and maximum tibial rotation values were examined. Peak EMG values were also analysed after being normalised and expressed as a percentage of maximum voluntary contraction (MVC). RESULTS: Gluteus maximus (GM) activity is significantly increased when a resistance band is used during squatting. However, squatting with a resistance band is detrimental to knee kinematics as it leads to an increase in knee valgus angle and maximum tibial rotation angle. A direct correlation is recorded between an increase in resistance and an increase in these two angles. CONCLUSIONS: Squatting with resistance bands is likely to increase the risk of knee injury. Coaches and clinicians who already implement this technique are advised to remove resistance band squats from training and rehabilitation programmes. Further research evaluating the long-term effects of using resistance bands during the barbell back squat should be considered.

10.
BMJ Open Sport Exerc Med ; 5(1): e000568, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31798947

RESUMEN

OBJECTIVES: The lower limb is widely reported as the most commonly injured body part in the field of hockey, more specifically lateral ankle sprains and internal knee injury. Despite this, there remains limited understanding of how the biomechanics of the sport could be adapted to minimise injury. The aim of this study was to propose a foot position during the hockey hit that results in the smallest joint angles and moments, from a total of four different foot positions: 0°, 30°, 60° and 90°, which may correlate to injury risk. METHOD: Eighteen players from the local University Ladies Hockey Club participated in this study. Each player was required to perform a hit with their lead foot in four different positions: 0°, 30°, 60° and 90°, where 0° was a lead foot position perpendicular to the direction of motion of the ball. Angles and moments were calculated with the Vicon system using force plates and motion analysis. RESULTS: Significant differences (p<0.05) were found between the angles and moments of the four foot positions tested, indicating that foot angle can influence the degree of angulation, and moments, produced in the lower limb joints during the hockey hit. CONCLUSION: There is a relationship between lead foot position and the angles and moments produced in the lower limb joints during the hockey hit, and this may correlate with injury risk.

11.
BMJ Open Sport Exerc Med ; 5(1): e000582, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31548906

RESUMEN

OBJECTIVES: This study aimed to determine if ball position influences the risk of lower limb non-contact injury in hockey sweep pass. It also aimed to determine a ball position that minimises excessive strain placed on the lower limb joints of the lead leg during the sweep pass. METHODS: A cohort of 18 female hockey-playing volunteers (age: 19.7±1.5 years; height: 165.5±5.4 cm; body mass: 66.4±7.0 kg) were recruited. Participants performed the sweep pass using three different ball positions: in front, in line with, and behind the heel of the lead (left) foot.Motion analysis and force plate data were collected. Moments and angles in all three planes of motion for the three main lower limb joints were then calculated using Vicon software. Results were statistically analysed using SPSS software. RESULTS: Significant differences (p<0.05) were found between the three tested ball positions for the mean maximum angles and moments, and mean ranges of motion produced at the lead three main lower limb joints. Positioning the ball in line with the heel of the lead foot resulted in the lowest moments and angles when compared with the other two ball positions. CONCLUSIONS: The results indicate that positioning the ball in line with the heel of the lead foot is recommended to minimise the risk of injury to the lower limb joints during the hockey sweep pass. It is hoped that these findings will result in this position being implemented by players new to hockey or those returning to the sport following injury.

12.
Foot (Edinb) ; 38: A1-A2, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31088625
13.
BMJ Open Sport Exerc Med ; 4(1): e000361, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30498572

RESUMEN

AIM: To compare the available brands of rugby headguards and evaluate their impact attenuation properties at various locations on the cranium, with regard to concussion prevention. METHODS: Seven different branded headguards were fitted onto a rigid headform and drop-tested in three different positions. An accelerometer measured the linear acceleration the headform experienced on impact with the ground. Each test involved dropping the headform from a height that generated 103.8 g on average when bare, which is the closest acceleration to the upper limit of the concussion threshold of 100 g. A mean peak acceleration for each drop position was calculated and compared with the bare baseline measurement. RESULTS: Each headguard demonstrated a significant decrease in the mean peak acceleration from the baseline value (all p≤0.01). Overall the Canterbury Ventilator was the most effective headguard, decreasing the impact force on average by 47%. The least effective was the XBlades Elite headguard, averaging a force reduction of 27%. In five of the seven headguards, the right side of the headwear was the most effective at reducing impact force. CONCLUSION: Overall, the results indicate that it would be beneficial to wear a headguard during rugby in order to reduce the impact forces involved in head collisions. There was also a clear difference in performance between the tested brands, establishing the Canterbury headguard as the most effective. However, only one model of headguard from each brand was tested, so further research evaluating all other models should be considered.

14.
Surgeon ; 16(6): 339-349, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29907524

RESUMEN

BACKGROUND AND PURPOSE: Currently it is not clear whether age is a factor affecting revisions in total hip replacement (THR) and hip resurfacing (HR). This study aimed to investigate which of THR or HR has a higher risk in terms of revision and complication within similar age groups. METHODS: A systemic review was performed for published literature research databases and local data and compared the two procedures under the condition that both groups of patients were age matched. Meta-analysis techniques were used to analyse revision and complication rates. Twenty-seven literature studies were included along with local audit data. In total, 2520 HR procedures were compared with age-matched 2526 of THR procedures. MAIN FINDINGS: It was found that revision risk of HR is significantly higher than THR (risk ratio 1.65, 95% CI 1.28-2.31, p < 0.0001), highlighting that HR has a slightly higher chance of reoperation when compared to THR within the similar age group population. In terms of complications, HR was found to have an advantage over THR (risk ratio 0.84, 95% CI 0.73-0.96, p < 0.01). CONCLUSION: THR had a lower revision risk but a slightly higher complication risk than HR under the condition that the two surgical procedures were applied to similar age groups of patients. In other words, age has not played an important role in revision and complication. Survivorship cannot be measured as follow-up periods were different in the studies used.


Asunto(s)
Artroplastia de Reemplazo de Cadera/efectos adversos , Artropatías/cirugía , Complicaciones Posoperatorias/epidemiología , Reoperación/efectos adversos , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Artropatías/complicaciones , Artropatías/patología , Masculino , Persona de Mediana Edad , Factores de Riesgo
15.
Forensic Sci Int ; 284: 176-183, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29408727

RESUMEN

According to the College of Podiatry, footprints rank among the most frequent forms of evidence found at crime scenes, and the recent ascension of forensic podiatry reflects the importance of footwear and barefoot traces in contemporary forensic practice. In this context, this pilot study focused on whether it is possible to distinguish between walking and running states using parameters derived from two-dimensional foot or shoe prints. Eleven subjects moved along four tracks (barefoot walking; barefoot running; footwear walking; footwear running) while having their bare feet or footwear stained with artificial blood and their footstep patterns recorded. Contact stains and associated bloodstain patterns were collected, and body movements were recorded through three-dimensional motion capture. Barefoot walking prints were found to be larger than barefoot static prints (1.789±0.481cm; p<0.001) and barefoot running prints (0.635±0.405cm; p=0.006). No correlation was observed for footwear prints. Running trials were more associated with the presence of both passive and cast off stains than walking trials, and the quantity of additional associated stains surrounding individual foot and shoe prints was also higher in running states. Furthermore, a previously proposed equation predicted speed with a high degree of accuracy (within 6%) and may be used for clinical assessment of walking speed. Contact stains, associated bloodstain patterns and stride length measurements may serve to ascertain state of motion in real crime scene scenarios, and future studies may be capable of designing statistical frameworks which could be used in courts of law.


Asunto(s)
Pie , Carrera , Zapatos , Caminata , Fenómenos Biomecánicos , Manchas de Sangre , Femenino , Ciencias Forenses/métodos , Humanos , Masculino , Proyectos Piloto , Estadística como Asunto , Velocidad al Caminar , Adulto Joven
16.
Gut ; 67(3): 441-446, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-27965284

RESUMEN

OBJECTIVE: Microscopic colitis (MC) is a common cause of chronic diarrhoea, often with additional symptoms. No validated instruments exist to assess disease activity in MC, making it difficult to compare efficacy of treatments between clinical trials. We aimed to identify clinical features that independently predicted disease severity and create a Microscopic Colitis Disease Activity Index (MCDAI). DESIGN: Patients with MC were prospectively administered a survey assessing their GI symptoms and the IBD Questionnaire (IBDQ). A single investigator also scored a physician global assessment (PGA) of disease severity on a 10-point scale. Multiple linear regression identified which symptoms best predicted the PGA. These symptoms were then combined in a weighted formula to create the MCDAI. The relationship between MCDAI and the IBDQ was investigated. RESULTS: Of the 175 patients enrolled, 13 (7.4%) did not complete the survey. The remaining 162 had a median age of 66 years (range, 57-73) and 74% were female. Several clinical features were independently associated with PGA (number of unformed stools daily, presence of nocturnal stools, abdominal pain, weight loss, faecal urgency and faecal incontinence). These parameters were combined to create the MCDAI, which strongly predicted the PGA (R2=0.80). A 1-unit decrease in disease activity (ΔMCDAI) was associated with a 9-unit increase in quality of life (ΔIBDQ). CONCLUSIONS: The MCDAI strongly predicted the PGA and correlated with a validated measure of quality of life. Several symptoms in addition to diarrhoea are associated with disease severity in MC.


Asunto(s)
Colitis Microscópica/complicaciones , Calidad de Vida , Índice de Severidad de la Enfermedad , Dolor Abdominal/etiología , Anciano , Defecación , Diarrea/etiología , Incontinencia Fecal/etiología , Heces , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Encuestas y Cuestionarios , Evaluación de Síntomas
17.
Age Ageing ; 47(1): 75-81, 2018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-28985263

RESUMEN

Design: double-blind, parallel group, placebo-controlled randomised trial. Methods: we recruited people aged >65 years with at least one fall in the previous year. Participants received 4 mg perindopril or placebo daily for 15 weeks. The primary outcome was the between-group difference in force-plate measured anteroposterior (AP) sway at 15 weeks. Secondary outcomes included other measures of postural sway, limits of stability during maximal forward, right and left leaning, blood pressure, muscle strength, 6-min walk distance and falls. The primary outcome was assessed using two-way ANOVA, adjusted for baseline factors. Results: we randomised 80 participants. Mean age was 78.0 (SD 7.4) years; 60 (75%) were female. About 77/80 (96%) completed the trial. At 15 weeks there were no significant between-group differences in AP sway with eyes open (mean difference 0 mm, 95% CI -8 to 7 mm, P = 0.91) or eyes closed (mean difference 2 mm, 95% CI -7 to 12 mm, P = 0.59); no differences in other measures of postural stability, muscle strength or function. About 16/40 (42%) of patients in each group had orthostatic hypotension at follow-up. The median number (IQR) of falls was 1 (0,4) in the perindopril versus 1 (0,2) in the placebo group (P = 0.24). Conclusions: perindopril did not improve postural sway in older people at risk of falls. Clinical Trials Registration: ISRCTN58995463.


Asunto(s)
Accidentes por Caídas/prevención & control , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Perindopril/uso terapéutico , Equilibrio Postural/efectos de los fármacos , Trastornos de la Sensación/tratamiento farmacológico , Factores de Edad , Anciano , Anciano de 80 o más Años , Inhibidores de la Enzima Convertidora de Angiotensina/efectos adversos , Método Doble Ciego , Femenino , Evaluación Geriátrica , Humanos , Masculino , Perindopril/efectos adversos , Factores de Riesgo , Escocia , Trastornos de la Sensación/complicaciones , Trastornos de la Sensación/diagnóstico , Trastornos de la Sensación/fisiopatología , Factores de Tiempo , Resultado del Tratamiento
18.
BMJ Open Sport Exerc Med ; 3(1): e000221, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29021906

RESUMEN

BACKGROUND: The aim of this study was to determine whether toe sliding is more likely to cause knee injuries than flatfoot sliding in curling. METHODS: Twelve curlers participated in the study, each delivering 12 stones. Six stones per volunteer were delivered using a flatfoot slide and six were delivered using a toe slide. The Pedar-X in-shoe pressure system recorded the plantar pressure during each of the slides, while a sagittal plane digital video recorded the body position of the curler. Measurements were taken from the video recordings using a software overlay program (MB Ruler), and this, combined with the Pedar-X data, gave the overall joint force in the tuck knee. RESULTS: The knee joint force for toe sliding was more than double that of flatfoot sliding (p<0.05). There was a strong correlation between the increase in knee joint force and the increase in the moment arm of the ground reaction force. Images produced using the three-dimensional Vicon system confirm that toe sliding produces a larger moment arm than flatfoot sliding. CONCLUSION: Injuries are more likely to occur in toe sliding, compared with flatfoot sliding, due to the increase in force and moment, pushing the weight of the curler forward over the knee, which could make the adopted position less stable. Curlers might consider avoiding toe sliding to reduce the risk of knee injuries if the two types of delivery could be performed equally well.

19.
Shoulder Elbow ; 8(3): 184-91, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27583017

RESUMEN

BACKGROUND: Lateral epicondylitis (LE) occurs in almost half of all tennis players. Racket-string tension is considered to be an important factor influencing the development of LE. No literature yet exists that substantiates how string-tension affects force transmission to the elbow, as implicated in LE development. We establish a quantitative relationship between string-tension and elbow loading, analyzing tennis strokes using rackets with varying string-tensions. METHODS: Twenty recreational tennis players simulated backhand tennis strokes using three rackets strung at tensions of 200 N, 222 N and 245 N. Accelerometers recorded accelerations at the elbow, wrist and racket handle. Average peak acceleration was determined to correlate string-tension with elbow loading. RESULTS: Statistically significant differences (p < 0.05) were observed when average peak acceleration at the elbow at 200 N string-tension (acceleration of 5.58 m/s(2)) was compared with that at 222 N tension (acceleration of 6.83 m/s(2)) and 245 N tension (acceleration of 7.45 m/s(2)). The 200 N racket induced the least acceleration at the elbow. CONCLUSIONS: Although parameters determining force transmission to the elbow during a tennis stroke are complex, the present study was able to control these parameters, isolating the effect of string-tension. Lower string-tensions transmit less force to the elbow in backhand strokes. Reducing string-tension should be considered favourably with respect to reducing the risk of developing LE.

20.
Ergonomics ; 58(11): 1868-77, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25952275

RESUMEN

This study investigated whether using an armrest could reduce the movements of the trunk, upper limb and hand of surgeons during simulated minimal access surgery. Sixteen surgeons carried out two trials of simulated laparoscopic surgery, one using an armrest and the other without. Reflective markers were attached on the trunk, upper limbs, fingers, minimal access camera (MAC) and scissors, allowing a motion capture system to record the movements. The error ratios during operation, subjective opinions and operative durations were collected. The results showed that total displacements at the trunk and shoulders were reduced by at least 25% when using an armrest compared with not using one; error ratios were reduced by 7%; velocity and acceleration in the trunk, shoulder and MAC were reduced. After simulated operations, 78% of the participants preferred using the armrest. The study indicates that an armrest could improve surgical outcomes by reducing trunk movements. PRACTITIONER SUMMARY: An armrest may help surgeons to reduce unnecessary movements during operations. The error ratios were reduced by 7% when using an armrest compared with no armrest. Displacements at the trunk and shoulders were reduced by 25% when using an armrest. Seventy-eight per cent of participants preferred to use an armrest after the experiment.


Asunto(s)
Procedimientos Quirúrgicos Mínimamente Invasivos , Cirujanos Ortopédicos , Equipo Quirúrgico , Torso , Extremidad Superior , Interfaz Usuario-Computador , Adulto , Brazo , Fenómenos Biomecánicos , Dedos , Humanos , Laparoscopía , Masculino , Persona de Mediana Edad , Movimiento , Hombro
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