Poor peak dorsiflexor torque associated with incidence of ankle injury in elite field female hockey players

This study set out to determine the incidence of ankle injuries amongst provincial female field hockey players in KwaZulu-Natal (KZN), South Africa, during the 2004 field hockey season and relate this to their injury and playing profile, proprioceptive ability and peak isokinetic torque of the ankle plantar and dorsiflexor muscles. Players participating in the senior, U21 and U19/high school provincial A teams (n = 47) detailed their hockey playing and training history and injuries sustained during the 2004 season. A subsample of injured and matched, uninjured controls (n = 18) underwent anthropometric, proprioceptive and isokinetic testing. Incidence of injury in the 2004 season was 0.98 per player or 6.32 injuries per 1000 player/h⁻¹, with 25.5% of players (n = 12) reporting injuries to the ankle joint. All ankle injuries occurred on artificial turf and 75% occurred during a match. Forwards and links that had been playing for six to seven years presented with the highest incidence of ankle injuries. Injured players were able to maintain balance on a proprioceptive board for 10.31 ± 8.2 s versus 23.9 ± 15.3 s in matched, uninjured controls (p = 0.078). Both mean (27.4 ± 5.5 Nm versus 32.7 ± 4.7 Nm) and median (27.0, 23.0–31.5 versus 31.8, 30.0–35.1 Nm) peak isokinetic torque of the dorsiflexors of injured legs was significantly lower than in uninjured, contralateral legs of the injured players (p = 0.01 and 0.03, respectively). Poor peak dorsiflexion torque in the injured leg was identified as a factor associated with ankle injury in this sample of injured, elite field hockey players.     

Physiological and psychological responses to a 12-week BodyBalance training programme

BodyBalance is a popular mind–body program practised at numerous leisure centres throughout the western world that makes many unsubstantiated claims as to the benefits of participation. This study examines physiological and psychological responses in adults, aged (mean ± S.D.) 43.9 ± 10.9 years, to a 12-week ‘BodyBalance’ exercise program. An exercise intervention group (n = 17) undertook three 1-h classes, each week for 12 consecutive weeks while the control group (n = 17) attended three 90-min ‘health lectures’. ANCOVA demonstrated significant differences between the control and exercise groups in body mass, skinfold measures, total girth circumference from six sites, maximal isometric back strength, five measures of flexibility and state anxiety. Post-hoc tests on the experimental group data showed body fat decreased significantly by 1.10 ± 1.02% (t = 4.44; P < 0.01), girth by 4.40 ± 5.80 cm (t = 3.13; P < 0.01) and back strength increased by 17.12 ± 15.39 kgf (t = −4.59; P < 0.01). Flexibility was also significantly enhanced with performance of the modified sit-and-reach test increasing by 5.90 ± 2.56 cm (t = −9.50; P < 0.01), hip flexion by 9.84 ± 8.41° (t = −4.82; P < 0.01), hip extension by 7.65 ± 4.48° (t = −7.04; P < 0.01), hip abduction by 10.00 ± 4.91° (t = −8.40; P < 0.01) and lateral trunk flexion by 3.06 ± 5.72° (t = −2.21; P < 0.05). Finally, state-anxiety (STAI) was significantly reduced intra-class at weeks 1, 6 and 12 by 9.24 ± 9.46 (t = 4.02; P < 0.01), 6.59 ± 6.26 (t = 4.34; P < 0.01) and 7.18 ± 5.50 (t = 5.38; P < 0.01), respectively. The findings of this study suggest mind–body exercise programs like BodyBalance could significantly benefit state-anxiety as well as strength, flexibility, and anthropometry around the trunk.     

Comparison of plantar loads during running on different overground surfaces

The objective of this study is to compare plantar loads during running on different overground surfaces. Fifteen heel-to-toe runners participated in the study. Plantar load data were collected and analyzed using an insole sensor system during running on concrete, synthetic rubber, and grass surfaces at a running speed of 3.8 m/s. Compared with running on concrete surface, running on natural grass showed a lower magnitude of maximum plantar pressure at the total foot (451.8 kPa vs. 401.7 kPa, p = 0.016), lateral midfoot (175.3 kPa vs. 148.0 kPa, p?=?0.004), central forefoot (366.3 kPa vs. 336.8 kPa, p = 0.003), and lateral forefoot (290.2 kPa vs. 257.9 kPa, p = 0.004). Moreover, running on natural grass showed a longer relative contact time compared with running on a concrete surface at the central forefoot (81.9% vs. 78.8%, p = 0.017) and lateral forefoot (75.2% vs. 73.1%, p = 0.007). No significant difference was observed in other multiple comparisons. Different surfaces affected the plantar loads while running. The differences may help us to understand potential injury mechanisms.     

Does an eccentric chainring improve conventional parameters of neuromuscular power?

This study compared the conventional parameters of anaerobic cycling power in physically active non-cyclists using the Pro-Race^® system and a traditional chainring. The force–velocity test was chosen for this purpose because it is the shortest validated cycling laboratory test in which each parameter of maximal anaerobic power can be estimated. The power output (W_max) and the force at which W_max is produced (F_opt) were significantly improved with the eccentric chainring (1100 ± 227 W versus 1006 ± 197 W and 1.39 ± 0.15 N/kg body mass versus 1.13 ± 0.16 N/kg body mass with the eccentric and round designs, respectively; P < 0.006 and P < 0.0004, respectively). The power gained (delta power) was significantly correlated with the eccentric chainring F_opt (r = 0.649; P < 0.05), the mid-thigh circumference (r = 0.685; P < 0.05), the estimated lean thigh volume (r = 0.765; P < 0.01) and the estimated lean lower limb volume (r = 0.665; P < 0.05). We concluded that the eccentric chainring significantly improved the estimated anaerobic power output during a force–velocity test by increasing the force component, F_opt. Cautious interpretation of our results suggests that the subjects with physical attributes that contribute to developing high forces may have a significant advantage in performing with the eccentric chainring.     

In-shoe plantar pressure measurements for the evaluation and adaptation of foot orthoses in patients with rheumatoid arthritis: A proof of concept study

ObjectivesImproving foot orthoses (FOs) in patients with rheumatoid arthritis (RA) by using in-shoe plantar pressure measurements seems promising. The objectives of this study were to evaluate (1) the outcome on plantar pressure distribution of FOs that were adapted using in-shoe plantar pressure measurements according to a protocol and (2) the protocol feasibility.MethodsForty-five RA patients with foot problems were included in this observational proof-of concept study. FOs were custom-made by a podiatrist according to usual care. Regions of Interest (ROIs) for plantar pressure reduction were selected. According to a protocol, usual care FOs were evaluated using in-shoe plantar pressure measurements and, if necessary, adapted. Plantar pressure–time integrals at the ROIs were compared between the following conditions: (1) no-FO versus usual care FO and (2) usual care FO versus adapted FO. Semi-structured interviews were held with patients and podiatrists to evaluate the feasibility of the protocol.ResultsAdapted FOs were developed in 70% of the patients. In these patients, usual care FOs showed a mean 9% reduction in pressure–time integral at forefoot ROIs compared to no-FOs (p = 0.01). FO adaptation led to an additional mean 3% reduction in pressure–time integral (p = 0.05). The protocol was considered feasible by patients. Podiatrists considered the protocol more useful to achieve individual rather than general treatment goals. A final protocol was proposed.ConclusionsUsing in-shoe plantar pressure measurements for adapting foot orthoses for patients with RA leads to a small additional plantar pressure reduction in the forefoot. Further research on the clinical relevance of this outcome is required.     

Surface-related injuries in soccer

The review of the effects of artificial turf and natural grass on surface-related traumatic injuries in soccer suggests that surfaces with artificial turf produce more abrasion injuries than surfaces with natural grass. Most authors report no significant difference in injury frequencies for the number of traumatic injuries. However, some authors report fewer traumatic injuries on artificial turf, especially after a period of adaptation on the artificial turf. A difference in injury pattern and injury mechanism when playing on different types of surfaces has been suggested, as well as an increased injury risk for frequent alternating between different playing surfaces. The relationship between knee and ankle injuries and the fixation of the foot to the ground is not yet evaluated in soccer. In American football, the severity and incidence of knee and ankle injuries were reported to be significantly lower when using shoes with lower friction properties. However, in American football severe injuries typically occur in collision situations often independent of the surface. Soccer is characterised by sprinting, stopping, cutting and pivoting situations, where shoe-surface relations are essential and frictional resistance must be within an optimal range. Future research should address this compromise between performance and protection.     

Endurance of the ankle joint plantar flexor muscles in athletes with medial tibial stress syndrome: A case-control study

Medial tibial stress syndrome (MTSS) is a common overuse leg injury seen in athletes and can be recalcitrant to management. This cross-sectional study aimed to determine if there are differences in the isotonic endurance of the ankle joint plantar flexor muscles in athletes with MTSS compared to athletes without MTSS. The isotonic endurance of the ankle joint plantar flexors was measured in 30 participants diagnosed with MTSS, and 30 reference participants that were matched to MTSS participants on the basis of age (±5 years), gender, BMI (±5%) and type of sporting activity. The number of heel-rise repetitions of the participants in each group was compared for differences. There were no significant differences between participants with and without MTSS for age (p = 0.34), height (p = 0.40) or BMI (p = 0.27). The mean number of heel-rise repetitions performed by participants in the MTSS group was significantly less than the reference group (mean 23, S.D. 5.6, versus mean 33, S.D. 8.6; p < 0.001). These results suggest that athletes with MTSS have endurance deficits of the ankle joint plantar flexor muscles. Rehabilitation of athletes with MTSS should comprise training designed to enhance endurance of the lower limb musculature, including the ankle joint plantar flexors. It is not known whether a lack of endurance of the ankle joint plantar flexor muscles is the cause or effect of MTSS.     

Comparison of injuries sustained on artificial turf and grass by male and female elite football players

The objective of this study was to compare incidences and patterns of injury for female and male elite teams when playing football on artificial turf and grass. Twenty teams (15 male, 5 female) playing home matches on third‐generation artificial turf were followed prospectively; their injury risk when playing on artificial turf pitches was compared with the risk when playing on grass. Individual exposure, injuries (time loss) and injury severity were recorded by the team medical staff. In total, 2105 injuries were recorded during 246 000 h of exposure to football. Seventy‐one percent of the injuries were traumatic and 29% overuse injuries. There were no significant differences in the nature of overuse injuries recorded on artificial turf and grass for either men or women. The incidence (injuries/1000 player‐hours) of acute (traumatic) injuries did not differ significantly between artificial turf and grass, for men (match 22.4 v 21.7; RR 1.0 (95% CI 0.9–1.2); training 3.5 v 3.5; RR 1.0 (0.8–1.2)) or women [match 14.9 v 12.5; RR 1.2 (0.8–1.8); training 2.9 v 2.8; RR 1.0 (0.6–1.7)]. During matches, men were less likely to sustain a quadriceps strain (P=0.031) and more likely to sustain an ankle sprain (P=0.040) on artificial turf.     

Aerobic fitness and field test performance in elite Spanish soccer referees of different ages

The major aim of this study was to examine the physical fitness of elite Spanish soccer referees in relation to their age. A secondary aim was to assess the population criterion validity of the 12 min running test (12 MRT) against aerobic-fitness laboratory tests. Participants were 45 soccer referees (age 35.5 ± 4.4 years, height 178.3 ± 5.0 cm, body mass 75.1 ± 6.6 kg, body fat 11.3 ± 2.15%, VO_2max 54.9 ± 3.9 ml kg⁻¹ min⁻¹) who were enrolled in the Referees Technical Committee of the Royal Spanish Soccer Federation. They were divided into three age groups: young (Y, 27–32 years, n = 15), average (A, 33–38 years, n = 17) and old (O, 39–45 years, n = 13). No age-related effects were observed for VO_2max, 12 MRT or 200 m sprint performance in either the pooled or grouped data. However, age-related performance decrements were observed for 50 m sprint performance and the ventilatory threshold (VT) running speed. Twelve MRT performance was moderately related to VO_2max (r = 0.46, P = 0.002), VT (km h⁻¹) (r = 0.49, P < 0.001), and peak treadmill velocity (PTV) (r = 0.60, P < 0.001). The results showed that older elite-level referees may be able to limit the expected age-related performance decrements in both aerobic and anaerobic performance usually reported for sedentary people. Additionally, these results show that older referees are able to reach physical fitness levels that have been suggested to be appropriate for coping with match demands.     

Influence of exercise mode and maximal lactate-steady-state concentration on the validity of OBLA to predict maximal lactate-steady-state in active individuals

The aim of this study was to analyze the effects of exercise mode on the validity of onset of blood lactate accumulation (OBLA—3.5-mM fixed blood lactate concentration) to predict the work-rate at maximal lactate steady state (MLSS_work-rate). Eleven recreationally active males (21.3 ± 2.9 years, 72.8 ± 6.7 kg, 1.78 ± 0.1 m) performed randomly incremental tests to determine OBLA (stage duration of 3 min), and 2 to 4 constants work-rate exercise tests to directly determine maximal lactate steady state parameters on a cycle-ergometer and treadmill. For both exercise modes, the OBLA was significantly correlated to MLSS_work-rate, (cycling: r = 0.81 p = 0.002; running: r = 0.94, p < 0.001). OBLA (156.2 ± 41.3 W) was lower than MLSS_work-rate (179.6 ± 26.4 W) during cycling exercise (p = 0.007). However, for running exercise, there was no difference between OBLA (3.2 ± 0.6 m s⁻¹) and MLSS_work-rate (3.1 ± 0.4 m s⁻¹). The difference between OBLA and MLSS_work-rate on the cycle-ergometer (r = 0.86; p < 0.001) and treadmill (r = 0.64; p = 0.048) was significantly related to the specific MLSS. We can conclude that the validity of OBLA on predicting MLSS_work-rate is dependent on exercise mode and that its disagreement is related to individual variations in MLSS.     

Characteristic plantar pressure distribution patterns during soccer-specific movements

PURPOSE: To characterize in-shoe pressure measurements during different soccer-specific maneuvers on two playing surfaces to identify the main loading areas of the foot. METHODS: Twenty-one experienced male soccer players participated in the study (25.5 +/- 1.8 years, 78.7 +/- 5.4 kg, and 182.9 +/- 5.7 cm). The Pedar Mobile system was used to collect plantar pressure information inside the soccer shoe. Four soccer-specific movements were performed (normal run, cutting maneuver, sprint, and goal shot) on both a grass and a red cinder surface. RESULTS: Results showed characteristic pressure distribution patterns with specific loading areas of the foot that correspond to the evaluated movements. In addition, loading patterns with higher pressure values than those observed during normal run were found. In cutting, the medial part of the foot; in sprinting, the first and second ray; and in kicking, the lateral part of the foot are predominantly loaded. No global effect of the two surfaces on pressure parameters was found. CONCLUSION: The results of the present investigation suggest that the high load in soccer in combination with a high repetition may have an important influence in the development of overuse injuries.     

Reliability of peak foot pressure in patients with previous diabetic foot ulceration

BackgroundPrevious reliability studies on peak plantar pressure measurements in patients with previous diabetic foot ulceration (DFU) did not stratify their analyses according to whether the foot had a previous ulcer.Research questionDoes test-retest reliability of peak foot pressure measurements from the various foot regions differ between the ulcerated and non-ulcerated feet?MethodsData from 23 participants with peripheral neuropathy and healed plantar DFU were analysed in this test-retest reliability comparison study. Plantar pressure was evaluated on two sessions using Pedar^®-X in-shoe system, with a mean of 7.2 days (SD = 1.6) between sessions.ResultsThe intraclass correlation coefficient (ICC) and coefficient of variation (CV) were calculated for 10 foot regions. Overall, test-retest reliability was excellent (ICCs, 0.82 to 0.95) for all peak pressure variables. CV ranged between 6.3% and 18.3%, and exceeded 15% over the hallux and medial forefoot regions in the ulcer foot (18.3% and 16.4%, respectively). Hallux peak pressure CV was significantly higher over the ulcer foot than over the non-ulcer foot (5.7%, 95% CI, 1.7%–10.2%). Peak pressure CV over the forefoot also tended to be higher over the ulcer foot (medial forefoot: 6.1%, 95% CI, -0.5%–14.5%; lateral forefoot: 4.1%, 95%CI, -0.7%–11.1%).SignificancePeak plantar foot pressure may be useful to distinguish between groups of patients with peripheral neuropathy and healed plantar DFU. However, clinical decisions based on ulcer foot hallux and forefoot peak pressure measurements should be interpreted with caution.     

The effects of off-the-shelf in-shoe heel inserts on forefoot plantar pressure

Off-the-shelf heel inserts are used widely without adequate scientific information regarding their effects upon the forefoot. The aim of this study was to assess whether the use of in-shoe heel inserts affects the plantar pressure distribution under the forefoot. Thirty-five asymptomatic volunteers consented to participate. Six brands of off-the-shelf heel inserts were tested. Subjects walked along a 10 m walkway with no inserts and then with each pair of inserts, in a randomised order. The Pedar system was used to record in-shoe plantar pressure data. The results confirmed that heel inserts increased pressure under the metatarsal heads and altered the biomechanics of the foot even in asymptomatic subjects. The findings suggested that heel inserts should be used with caution especially in people predisposed to foot problems. The classification of these inserts as an over-the-counter product may need to be reviewed.     

Comparison of plantar pressure distribution in adolescent runners at low vs. high running velocity

This study aimed to compare foot plantar pressure distribution while jogging and running in highly trained adolescent runners. Eleven participants performed two constant-velocity running trials either at jogging (11.2 ± 0.9 km/h) or running (17.8 ± 1.4 km/h) pace on a treadmill. Contact area (CA in cm(2)), maximum force (F(max) in N), peak pressure (PP in kPa), contact time (CT in ms), and relative load (force time integral in each individual region divided by the force time integral for the total plantar foot surface, in %) were measured in nine regions of the right foot using an in-shoe plantar pressure device. Under the whole foot, CA, F(max) and PP were lower in jogging than in running (-1.2% [p<0.05], -12.3% [p<0.001] and -15.1% [p<0.01] respectively) whereas CT was higher (+20.1%; p<0.001). Interestingly, we found an increase in relative load under the medial and central forefoot regions while jogging (+6.7% and +3.7%, respectively; [p<0.05]), while the relative load under the lesser toes (-8.4%; p<0.05) was reduced. In order to prevent overloading of the metatarsals in adolescent runners, excessive mileage at jogging pace should be avoided.     

The effect of playing surface on injury rate: a review of the current literature

Synthetic playing surfaces are widely used for field and court sports. Artificial turf surfaces are commonly used as an alternative to natural grass, while outdoor surfaces like clay and acrylic are also prevalent. The effect of these synthetic surfaces on injury rates has not been clearly established. The available literature is largely limited to football and soccer data and the majority of studies are short-term. Confounding variables such as climate, player position and footwear, as well as varying definitions of injury, also make it difficult to draw firm conclusions about the general effect of artificial playing surfaces on injury rates. Many peer-reviewed studies cite a higher overall rate of injury on first- and second-generation artificial turf surfaces compared with natural grass. Despite differences in injury type, the rate of injury on third-generation and natural grass surfaces appears to be comparable. It also appears that clay is significantly safer than either grass or hard court tennis surfaces, but this is a conclusion drawn with limited data. Further research investigating overall injury trends as well as sport-specific data is needed to draw more definitive conclusions regarding the effect of artificial playing surfaces on injury rates.     

A method for manipulating a movable platform's axes of rotation: a novel use of the CAREN system

The functionality of movable platforms used in human balance studies is limited as they allow rotations around pre-defined axes, which typically run close to the platform's surface and so cannot be used to directly investigate control mechanisms of proximal joints. A new six degrees of freedom platform (CAREN, Motek, Amsterdam) is now available which in principle could be programmed to rotate around any axis of rotation. The location of the default axes of rotation for this device are not documented and the algorithm to move the axes has not yet been defined. The purpose of this study was to (1) locate the platform's default axes of rotation, (2) implement an algorithm for relocating its axes of rotation and (3) evaluate the algorithm. A simplified method was developed to locate the bounding rectangles within which the default axes of rotations were located. The three axes of rotation were found to be at x = 1.13 ± 0.69 mm, z = −204.22 ± 0.63 mm in the roll plane, y = −2.67 ± 0.59 mm, z = −211.38 ± 0.63 mm in the pitch plane and x = 0.43 ± 0.70 mm, y = −4.72 ± 0.65 mm in the yaw plane (X: left, Y: rear, Z: up), relative to the centre of its surface, with the maximum bounding rectangle of dimensions 2.50 mm by 2.42 mm. Relocation of the platform's axes of rotation was achieved by the use of compensatory corrections, which were determined using a translation algorithm. Evaluation of the algorithm involved pitching the platform around three newly defined axes in the sagittal plane, representing the ankle, knee and hip joints. The platform was able to rotate around the new axes while keeping the instantaneous axes of rotation within bounding rectangles of 1.87 mm × 0.81 mm (ankle), 3.04 mm × 1.23 mm (knee), 3.14 mm × 1.63 mm (hip). The ability to overcome the limitation of other moveable platforms makes the CAREN system a valuable tool in research on the role of individual joints in balance.     

Self-reported skin cancer protection strategies and location of skin cancer in retired cricketers: A case study from membership of the Emu Cricket Club

Cricket is one of Australia's most popular sports with approximately 470,000 registered participants. Played as a summer sport, participants can spend long periods in the sun with potential skin damage a possible contributor to skin cancer. Three hundred and sixty-eight retired regional representative players received and were invited to complete a comprehensive survey that included questions relating to their individual playing history, injury rate, sun protection strategies and reported location of skin cancer. A total of 164 players (mean age 45.2 ± 12.1 years) responded to the survey representing a response rate of 44.6%. Of these, 61.6% reported no diagnosis of skin cancer. However, 38.4% had been diagnosed with at least one skin cancer with the most common site being the face followed by the arms. Of those respondents reporting the diagnosis of a skin cancer, 7.9% had skin cancer on 4 or more separate locations. Proportionally, the 45–55 years group had the highest incidence, with 55.8% of this group indicating they had a skin cancer in at least one anatomical location. By comparison those in the under 35 years age group reported an incidence rate of 16.7%. The incidence of skin cancer among respondents (n = 63) reporting either, occasionally, very rarely or never wearing sunscreen, a hat or long sleeved shirt was (n = 27) 42.9, (n = 14) 22.2 and (n = 39) 61.9%, respectively. The results suggest that skin protection strategies, such as wearing a wide brimmed hat, long sleeved shirt and the use of sunscreen, may help to reduce the risk of skin cancer in cricketers.     

Pressure characteristics in painful pes cavus feet resulting from Charcot-Marie-Tooth disease

Charcot–Marie–Tooth (CMT) disease often presents with peripheral muscle imbalance associated with a painful cavus (medial high-arched) foot deformity which becomes increasingly severe and rigid as the disease progresses. The purpose of this study was to investigate the effect of pes cavus on foot pain and dynamic plantar pressure in CMT, and to explore the relationships between plantar pressure and pain. Sixteen participants diagnosed with CMT and painful pes cavus were assessed for foot posture, ankle dorsiflexion range of motion, levels of foot pain, functional impairment, health-related quality of life and plantar pressure distribution while walking. Plantar pressure parameters (mean pressure, peak pressure, pressure–time integral) and contact duration were measured using the Novel Pedar^® in-shoe capacitance transducer system and the foot was divided into rearfoot, midfoot and forefoot regions for analysis. Increasing cavus foot deformity was associated with more widespread foot pain and increased pressure under the forefoot and midfoot regions. In contrast, peak pressure decreased under the rearfoot. Neither relationship was found between foot pain intensity and any of the pressure variables, nor was ankle dorsiflexion range of motion correlated with pain location, intensity or degree of pes cavus. Although pes cavus in CMT is associated with substantial pain and dysfunction, there is no clear link between foot pain and plantar pressure. The more severe the degree of pes cavus, however, the more pressure develops under the lateral margin of the foot; probably as a result of the changed foot–ground contact seen during gait.     

Between-day reliability of repeated plantar pressure distribution measurements in a normal population

The objective of this study was to determine the reliability of repeated plantar pressure distribution measurements during normal gait across multiple testing sessions. Testing sessions were conducted on 5 separate days at approximately the same time of day. Nine subjects (five males, four females, age 26 ± 8.4 years) who were free of any musculoskeletal injury were recruited. A capacitive pressure distribution platform (EMED AT, Novel GmbH, Munich, Germany), sampling at 50 Hz was used to collect plantar pressure patterns during barefoot walking at a self-selected speed. Four parameters were investigated: peak pressure, maximum force, impulse, and contact time, and these were investigated in 10 areas of the foot after using the PRC mask method of subdividing the foot into ten anatomical areas of interest. Individual means of all the five repeated trials for each foot were calculated, and these values were used to calculate intraclass correlation coefficients (ICC) and coefficients of variation (CoV) for all parameters. The results of this investigation show a generally good level of reliability, the quality of which is dependent on the region of the foot and the parameter investigated. Areas with typically high loading characteristics, such as the central forefoot showed a higher level of reliability in the ICC's (>0.9) than less loaded areas such as the medial midfoot (<0.8). The conclusion of this study is that plantar pressure distribution measurements can be used in comparative evaluations since the measures of repeatability are satisfactory for the parameters and foot regions usually used in the investigation of clinical populations such as neuropathic diabetics.     

Changes to stance limb peak,cumulative, and regional plantar foot forces among normal walking and three mobility aids in healthy older adults

BackgroundMobility aids are commonly prescribed to offload an injured lower extremity. Device selection may impact stance foot loading patterns and foot health in clinical populations at risk of foot ulceration.Research questionsTwo questions motivated this study: How does device selection influence peak plantar and regional (rearfoot, mid foot and forefoot) foot forces on the stance foot? Does device selection influence peak, cumulative, and regional plantar forces within a 200 m walking trial?MethodsTwenty-one older adults walked 200 m at self-selected pace in four randomized conditions for this prospective crossover study. Participants used a walker, crutches, wheeled knee walker (WKW), and no assistive device (control condition). Plantar forces were measured using a wireless in-shoe system (Loadsol, Novel Inc., St. Paul, MN). Repeated measures analyses of variance were used to determine differences in peak and cumulative total and regional forces among walking conditions. Paired sample t-tests compared forces during first and last 30 s epochs of each condition to determine device influence over time.ResultsThe WKW reduced peak net forces by 0.29 and 0.35 bodyweight (BW) when compared to the walker or control condition with similar trends in all foot regions. Crutch use had similar peak forces as control. There were no differences in the number of steps taken within devices comparing first and last epochs. Crutches had a 0.04 and 0.07 BW increase in peak net and forefoot forces during the last epoch. Walker use had 66.44 BW lower cumulative forefoot forces in the last epoch.SignificanceCrutches had similar stance foot loading as normal walking while a walker lowered forefoot forces at the expense of increased steps. A WKW may be the best choice to ‘protect’ tissues in the stance foot from exposure to peak and cumulative forces in the forefoot region.