R.J. Abboud

Repeatability of the Pedar-X in-shoe pressure measuring system.

BACKGROUND The Pedar-X is one of the newer versions of in-shoe pressure measuring devices and the current study aimed to assess the repeatability of this device. METHODS Twenty-seven healthy male volunteers were recruited and requested to walk on a 26-feet walkway wearing appropriate sized standardised off-the-shelf neutral running shoes (Donnay International). The Pedar-X insole was sandwiched between the foot and the shoe. Data were collected on two occasions, one week apart. Clinically relevant parameters studied were contact area, contact time in percentage roll over process, maximum force, pressure-time integral, force-time integral, peak pressure, mean force and mean area. RESULTS Repeatability was analysed using the coefficient of variation. Of the 160 parameters considered, 93.1% revealed a coefficient of variation value of less than 25. Heel and the metatarsal head areas were the most repeatable. CONCLUSION The Pedar-X in-shoe pressure measuring system is repeatable and as such can be used as a valuable tool in the assessment of in-shoe plantar pressure distribution.

Lower limb muscle dysfunction may contribute to foot ulceration in diabetic patients

OBJECTIVES To investigate the relationship between in-shoe plantar foot pressure and the co-ordinated activity of five lower limb muscles of diabetic patients, who are known to have a higher risk of foot morbidity. DESIGN A portable six channel electromyographic system has been designed, developed and synchronised in real time with a 16 channel piezoelectric transducer in-shoe pressure measuring device, Gaitscan. BACKGROUND So far, no one has tried to establish a relationship between in-shoe foot pressure distribution and muscle activity of the lower limb in diabetes. The measurement of phasic muscle activity has been related to foot pressure and compared to a control group of normal volunteers. METHODS Twenty nine diabetic subjects and 22 healthy non-diabetic volunteers have been studied by recording electromyography of lower leg muscles and in-shoe foot pressure measurements simultaneously. RESULTS In diabetic subjects, the period of contact pressure was greater than in normal control subjects (P<0.003). The initial forefoot time to contact with the ground was shorter in diabetics when compared to controls, indicating a faster forefoot contact. Of the dorsiflexor muscles, the Anterior Tibialis, normally contracting eccentrically at heel strike, was subject to a measurable delay in the initiation of contraction, of mean difference of 180 ms (P<0.001), in diabetic subjects when compared to the normal controls. CONCLUSIONS The late firing of Tibialis Anterior means that its normal modulating role in lowering the foot to the ground after heel strike through eccentric contraction is disturbed. The result is that the foot reaches the foot flat stage in a less ordered manner, subjecting it to high plantar pressures. RELEVANCE The results obtained may assist in planning realignment procedures of the foot and help prevent development of ulcers on the sole of the foot in high risk diabetic subjects.

Foot pressure differences in men and women

BACKGROUND Women and men are anatomically and physiologically different in a number of ways. Anthropometric studies have shown considerable differences in the foot bones of both genders. These differences could potentially mean different foot pressures in men and women. OBJECTIVE The aim of our study was to investigate any potential foot pressure differences between males and females using the Pedar-M (Novel gmbh, Germany) in-shoe foot pressure measurement system. METHODS Twenty-eight subjects (16 females and 12 males) were recruited. Peak pressure, contact area, contact time, pressure-time integral, force-time integral, instant of peak pressure, maximum force and mean force were recorded and subsequently analysed. RESULTS In males, contact area was significantly larger in all regions of the foot compared with females. There were no significant between gender differences in peak pressure, contact time, pressure-time integral and instant of peak pressure. Force-time integral was significantly greater in males than females under the 1st, 3rd, and 4th metatarsal heads. Maximum force was also significantly higher in males under the heel, 1st and 3rd metatarsal heads. Mean force was greater in males under the 3rd metatarsal head. CONCLUSION There were no peak pressure differences; however the contact area of the male foot was larger than that in females.

Mechanisms of cervical spine injury in Rugby Union: a systematic review of the literature

Background Severe cervical spine injury in rugby union (rugby) exerts a major impact on the individual who sustains the injury and on the broader society. Since the late 1970s, authors of rugby case report studies have postulated that the underlying mechanism of cervical spine injury is hyperflexion of the neck. However, this is in conflict with findings from more recent experimental studies. These have shown that it is more likely that the majority of cervical spine injuries occur due to buckling of the cervical spinal column. Objective To investigate the primary mechanism of cervical spine injury in rugby. Methods A comprehensive and systematic review of the literature was undertaken. Six key factors were identified and subsequently used to investigate the two principally postulated mechanisms of cervical spine injury: hyperflexion and buckling. Results Facet dislocations, in particular bilateral facet dislocations, were identified as the most common types of cervical spine injury in rugby. Trauma occurred most often at lower cervical spinal levels, notably the C4/5 and C5/6 motion segments. Experimental studies demonstrate that bilateral facet dislocations occurring at the lower cervical spinal levels are primarily produced via buckling. Conclusion Our analysis of key factors for cervical spine injury in rugby shows that it is unlikely that the majority of injuries occur after hyperflexion of the neck. It appears more likely that they are the result of buckling of the cervical spinal column.

Do you get value for money when you buy an expensive pair of running shoes

Objective: This investigation aims to determine if more expensive running shoes provide better cushioning of plantar pressure and are more comfortable than low-cost alternatives from the same brand. Methods: Three pairs of running shoes were purchased from three different manufacturers at three different price ranges: low (£40–45), medium (£60–65) and high (£70–75). Plantar pressure was recorded with the Pedar® in-shoe pressure measurement system. Comfort was assessed with a 100 mm visual analogue scale. A follow-on study was conducted to ascertain if shoe cushioning and comfort were comparable to walking while running on a treadmill. Forty-three and 9 male subjects participated in the main and follow-on studies, respectively. The main outcome measure was the evaluation of plantar pressure and comfort. Results: Plantar pressure measurements were recorded from under the heel, across the forefoot and under the great toe. Differences in plantar pressure were recorded between models and between brands in relation to cost. Shoe performance was comparable between walking and running trials on a treadmill. No significant difference was observed between shoes and test occasions in terms of comfort. Conclusions: Low- and medium-cost running shoes in each of the three brands tested provided the same (if not better) cushioning of plantar pressure as high-cost running shoes. Cushioning was comparable when walking and running on a treadmill. Comfort is a subjective sensation based on individual preferences and was not related to either the distribution of plantar pressure or cost.

Risk of periprosthetic fracture after anterior femoral notching A 9-year follow-up of 200 total knee arthroplasties

Background Notching of the anterior femoral cortex in distal femoral fractures following TKR has been observed clinically and studied biomechanically. It has been hypothesized that femoral notching weakens the cortex of the femur, which can predispose to femoral fractures in the early postoperative period. We examined the relationship between notching of the anterior femoral cortex during total knee replacement (TKR) and supracondylar fracture. Patients and methods Postoperative lateral radiographs of 200 TKRs were reviewed at an average of 9 (6–15) years postoperatively. 72 knees (41%) showed notching of the anterior femoral cortex. Notches were classified into 4 grades using the Tayside classification as follows. Grade I: violation of the outer table of the anterior femoral cortex; grade II: violation of the outer and the inner table of the anterior femoral cortex; grade III: violation up to 25% of the medullary canal (from the inner table to the center of the medullary canal); grade IV: violation up to 50% of the medullary canal (from the inner table to the center of the medullary canal) and unclassifiable. Results The interobserver variability of the classification system using Cohens Kappa score was found to be substantially reliable. 3 of the 200 TKRs sustained later supracondylar fractures. One of these patients had grade II femoral notching and the other 2 showed no notching. The patient with femoral notching sustained a supracondylar fracture of the femur following a simple fall at home 9 years after TKR. Interpretation There is no relationship between minimal anterior femoral notching and supracondylar fracture of the femur in TKR.

Do patients with diabetes wear shoes of the correct size

Background:  Fifteen per cent of patients with diabetes will develop a foot ulcer at some point in their life. Ill‐fitting footwear frequently contributes to foot ulceration. A good fitting shoe is an essential component in the management of the diabetic foot. The objective of this study was to assess the feet and footwear of patients with diabetes to determine whether they are wearing the correct‐sized shoes.

Shoes influence lower limb muscle activity and may predispose the wearer to lateral ankle ligament injury

Lateral ankle ligaments are injured by hyperinversion of the foot. Foot position is controlled by the lower limb muscles. Awareness of foot position is impaired by wearing shoes. We aimed to determine the influence of wearing shoes upon muscle activity. Sixty‐two healthy subjects underwent the same measurements, barefoot and with standardized shoes in a random order. Electromyography (EMG) was recorded from the peroneus longus muscle in response to sudden and unanticipated inversion of the ipsilateral foot. Following foot inversion, the EMG signal showed an initial peak muscle contraction followed by a sustained smaller contraction. Both changes were significantly greater in shoes compared to the barefoot condition for all tested degrees of inversion. Muscle contraction following sudden inversion of the foot was significantly greater when wearing shoes. This greater muscular contraction may be an intrinsic mechanism to oppose the increased moment created by the inverted foot/shoe condition, and hence, may counter balance the increased tendency to injure the lateral ankle ligaments created by wearing shoes.

Efficacy of low-level laser therapy applied at acupuncture points in knee osteoarthritis: a randomised double-blind comparative trial ☆

OBJECTIVE To evaluate the efficacy of low-level laser therapy (LLLT) applied to acupuncture points on the knee joint in combination with exercise and advice in patients with knee osteoarthritis. DESIGN Randomised, double-blind, comparative clinical trial. PARTICIPANTS Forty-nine patients with knee osteoarthritis were assigned at random into two groups: active laser group (n=26) and placebo laser group (n=23). INTERVENTION Using a gallium aluminium arsenide laser device, patients received either active or placebo LLLT at five acupuncture points on the affected knee during nine sessions. OUTCOME MEASURES Patients were assessed using a visual analogue scale (VAS) and the Saudi Knee Function Scale (SKFS) at baseline, the fifth treatment session, the last treatment session, 6 weeks post intervention and 6 months post intervention. RESULTS VAS scores showed a significant improvement in the active laser group compared with the placebo laser group at 6 weeks post intervention [mean difference -1.3, 95% confidence interval (CI) of the difference -2.4 to -0.3; P=0.014] and 6 months post intervention (mean difference -1.8, 95% CI of the difference -3.0 to -0.7; P=0.003) using the independent samples test. SKFS scores also showed a significant improvement in the active laser group compared with the placebo laser group at the last treatment session (median difference -15, 95% CI of the difference -27 to -2; P=0.035) and 6 months post intervention (median difference -21, 95% CI of the difference -34 to -7; P=0.006) using the Mann-Whitney U test. CONCLUSIONS The results demonstrate that short-term application of LLLT to specific acupuncture points in association with exercise and advice is effective in reducing pain and improving quality of life in patients with knee osteoarthritis.

Harmful cleats of football boots: A biomechanical evaluation

BACKGROUND Football players wear boots of varying cleat designs with some preferring the bladed cleats while others opting for the conventional studded cleats. The current study compares biomechanically the boots with differing cleat designs and their effect on feet, if any. METHODS Twenty-nine healthy male volunteers were recruited from amateur football teams. They were asked to perform three trials each of two activities: a straight run and a run cutting at a 60° angle wearing bladed and studded Adidas®-F series boots on artificial turf. Plantar pressure values were recorded using the Pedar®-X in-shoe pressure measuring device. Peak pressure and pressure-time integral were analysed over 11 clinically relevant areas under the foot. RESULTS While the in-shoe pressure and pressure-time integral were higher under the medial half of the foot with studded boots, they were higher under the lateral half of the foot with the bladed design. CONCLUSIONS The studded boots can be considered safer as the pressure distribution across the foot and the pattern of centre of pressure progression mimicked the normal motif, whereas the bladed boots could potentially be deemed relatively more harmful due to the unnatural increased loading under the lateral half of the foot, predisposing the foot to injuries.