Vegetation and Soil Comparisons Among Three Areas: Mowed, Relict, and Moderately Grazed

The purpose of this study was to determine effects of mowing and grazing on native vegetation of grasslands compared to a relict area. Three areas were selected in relation to past treatment: relict, mowed and moderately grazed. On each area two sites were selected, a breaks site and a limy upland site. The relict area used for study is located on southeast quarter of S6, T14S, R18W, mowed on southeast quarter of S35, T13S, R19W, and moderately grazed on southeast quarter of S36, T13S, R19W; all near Hays, Kansas in Ellis County. Vegetation of the three areas was sampled by the point transect method to determine percent composition, basal cover and frequency. A total of 400 sets or 4,000 points was taken at random. Yields were obtained by clipping eight square meter plots on each site. Soils of the three areas were analyzed for texture, pH and organic matter. Analysis was done to determine the amount of variation between the sites. Texture was determined by the Bouyoucos hydrometer method, pH by the Beckman pH meter and organic matter by wet digestion method. Dominant grasses on the relict breaks site were side-oats grama, big bluestem and little bluestem which made up 90.22 percent of the vegetation. The mowed breaks site supported the same dominant grasses as the relict site but little bluestem almost doubled in composition. Dominants on the grazed breaks site were side-oats grama with 30.10 percent and hairy grama with 19.97 percent composition. Tall grasses decreased and shortgrasses increased due to grazing on the breaks sites. Total basal cover for the relict, mowed, and grazed breaks sites was 21.51, 24.14 and 16.50 percent, respectively. Mowing increased basal cover but grazing decreased basal cover. Total forage yields on the relict, mowed and moderately grazed breaks sites was 2187.8, 1899.3 and 1975.0 pounds per acre, respectively. Dominant grass on the relict limy upland was big blue-stem but the dominant of mowed and grazed sites was side-oats grama. Big bluestem decreased and blue grama increased as a result of mowing and grazing on the limy upland sites. Just a trace of buffalo grass was found on the relict site but was abundant on the mowed and grazed sites. Total basal cover on the relict, mowed and grazed limy upland sites was 20.20, 30.25, and 28.82 percent, respectively. Total forage yields on the relict, mowed and grazed limy upland sites was 2403.4, 2278.4 and 2141.8 pounds per acre, respectively

How do patients with end-stage ankle arthritis decide between two surgical treatments?:A qualitative study

To examine how patients decide between ankle fusion and ankle replacement in end-stage ankle arthritis

Validity and Reliability of an Inertial Device for Measuring Dynamic Weight-Bearing Ankle Dorsiflexion

A decrease in ankle dorsiflexion causes changes in biomechanics, and different instruments have been used for ankle dorsiflexion testing under static conditions. Consequently, the industry of inertial sensors has developed easy-to-use devices, which measure dynamic ankle dorsiflexion and provide additional parameters such as velocity, acceleration, or movement deviation. Therefore, the aims of this study were to analyze the concurrent validity and test-retest reliability of an inertial device for measuring dynamic weight-bearing ankle dorsiflexion. Sixteen participants were tested using an inertial device (WIMU) and a digital inclinometer. Ankle dorsiflexion from left and right ankle repetitions was used for validity analysis, whereas test-retest reliability was analyzed by comparing measurements from the first and second days. The standard error of the measurement (SEM) between the instruments was very low for both ankle measurements (SEM 0.05) even though a significant systematic bias (~1.77°) was found for the right ankle (d = 0.79). R2 was very close to 1 in the left and right ankles (R2 = 0.85–0.89) as well as the intraclass correlation coefficient (ICC > 0.95). Test-retest reliability analysis showed that systematic bias was below 1° for both instruments, even though a systematic bias (~1.50°) with small effect size was found in the right ankle (d = 0.49) with WIMU. The ICC was very close to 1 and the coefficient of variation (CV) was lower than 4% in both instruments. Thus, WIMU is a valid and reliable inertial device for measuring dynamic weight-bearing ankle dorsiflexion

International Foot and Ankle Biomechanics Community (i-FAB): past, present and beyond

The International Foot and Ankle Biomechanics Community (i-FAB) is an international collaborative activity which will have an important impact on the foot and ankle biomechanics community. It was launched on July 2nd 2007 at the foot and ankle session of the International Society of Biomechanics (ISB) meeting in Taipei, Taiwan. i-FAB is driven by the desire to improve our understanding of foot and ankle biomechanics as it applies to health, disease, and the design,development and evaluation of foot and ankle surgery, and interventions such as footwear, insoles and surfaces

Tongue-placed tactile biofeedback suppresses the deleterious effects of muscle fatigue on joint position sense at the ankle

Whereas the acuity of the position sense at the ankle can be disturbed by muscle fatigue, it recently also has been shown to be improved, under normal ankle neuromuscular state, through the use of an artificial tongue-placed tactile biofeedback. The underlying principle of this biofeedback consisted of supplying individuals with supplementary information about the position of their matching ankle position relative to their reference ankle position through electrotactile stimulation of the tongue. Within this context, the purpose of the present experiment was to investigate whether this biofeedback could mitigate the deleterious effect of muscle fatigue on joint position sense at the ankle. To address this objective, sixteen young healthy university students were asked to perform an active ankle-matching task in two conditions of No-fatigue and Fatigue of the ankle muscles and two conditions of No-biofeedback and Biofeedback. Measures of the overall accuracy and the variability of the positioning were determined using the absolute error and the variable error, respectively. Results showed that the availability of the biofeedback allowed the subjects to suppress the deleterious effects of muscle fatigue on joint position sense at the ankle. In the context of sensory re-weighting process, these findings suggested that the central nervous system was able to integrate and increase the relative contribution of the artificial tongue-placed tactile biofeedback to compensate for a proprioceptive degradation at the ankle

The test-retest reliability of different ankle joint center location techniques

Accurate and reliable joint identification is imperative for the collection of meaningful kinetic and kinematic data. Of the lower kinetic chain both the hip and knee joints have received a considerable amount of attention in 3D modelling. However, the reliability of methods to define the ankle joint center have received very little attention. This study investigated the reliability of the two marker method (TMM) and the functional ankle method (FAM) on estimating the ankle joint center. Furthermore, the effects of the two-marker method reliability for defining the ankle joint center when the ankle was covered with a brace or protector was investigated. 3D kinematic data was collected from ten participants (8 female and 2 male) whilst walking. The ankle joint center was defined twice using each test condition; TMM (WITHOUT), FAM (FUNCTIONAL), TMM when the ankle was covered with a brace (BRACE), and TMM when the ankle was covered with a protector (PROTECTOR). Intraclass correlations (ICC) were utilised to compare test and retest waveforms and paired samples t-tests were used to compare angular parameters. Significant differences were found in the test-retest angular parameters in the transverse and sagittal planes for the WITHOUT, BRACE, and FUNCTIONAL conditions. The strongest test-retest ICC’s were observed in the WITHOUT and PROTECTOR conditions. The findings of the current investigation indicate that there are fewer errors using the TMM when the ankle is uncovered or when covered with soft foam that is easy to palpate through

Audit on the use of radiography and the management of ankle sprains in A&E

Objective: To determine the need for a local implementation strategy of the Ottawa Ankle and Foot rule in the A& E Department of St. Luke' s Hospital, Malta and to examine the current management practices of ankle sprains. Methods: A prospective study was conducted on all patients aged 16 years and over presenting to the A& E department of St. Luke’s Hospital, Malta over a six week period with ankle and midfoot injuries. Data collected included time and mechanism of injury, clinical examination findings, radiographic investigations ordered, management and disposal of patient. Results: Sixty nine (95%) of the 73 patients presenting with ankle injuries underwent x-ray investigation. In total 90 x-ray series (i.e. AP and lateral) were performed, 62 of which were ankle x-rays and 28 were foot x-rays. Clinical application of the Ottawa ankle rules (OAR) would have resulted in a reduction of ankle x-rays by 19.4% and foot x-rays by 32.1%. Management of severe ankle sprains included written discharge instructions in 54% and referrals to physiotherapy in 31%. One patient out of the 13 with severe ankle sprains was given a follow up appointment at Fresh Trauma Clinic (FTC). Conclusion: A local implementation strategy for the OAR in the A& E department may result in an overall reduction in radiographic requests by 21%. An appropriate guideline for management of ankle injuries incorporating the OAR is needed and should be developed using the available evidence base.peer-reviewedpeer-reviewe

Re-weighting of somatosensory inputs from the foot and the ankle for controlling posture during quiet standing following trunk extensor muscles fatigue

The present study focused on the effects of trunk extensor muscles fatigue on postural control during quiet standing under different somatosensory conditions from the foot and the ankle. With this aim, 20 young healthy adults were asked to stand as immobile as possible in two conditions of No fatigue and Fatigue of trunk extensor muscles. In Experiment 1 (n = 10), somatosensation from the foot and the ankle was degraded by standing on a foam surface. In Experiment 2 (n = 10), somatosensation from the foot and ankle was facilitated through the increased cutaneous feedback at the foot and ankle provided by strips of athletic tape applied across both ankle joints. The centre of foot pressure displacements (CoP) were recorded using a force platform. The results showed that (1) trunk extensor muscles fatigue increased CoP displacements under normal somatosensatory conditions (Experiment 1 and Experiment 2), (2) this destabilizing effect was exacerbated when somatosensation from the foot and the ankle was degraded (Experiment 1), and (3) this destabilizing effect was mitigated when somatosensation from the foot and the ankle was facilitated (Experiment 2). Altogether, the present findings evidenced re-weighting of sensory cues for controlling posture during quiet standing following trunk extensor muscles fatigue by increasing the reliance on the somatosensory inputs from the foot and the ankle. This could have implications in clinical and rehabilitative areas

Optimizing the Use of an Artificial Tongue-Placed Tactile Biofeedback for Improving Ankle Joint Position Sense in Humans

The performance of an artificial tongue-placed tactile biofeedback device for improving ankle joint position sense was assessed in 12 young healthy adults using an active matching task. The underlying principle of this system consists of supplying individuals with supplementary information about the position of the matching ankle relative to the reference ankle position through a tongue-placed tactile output device generating electrotactile stimulation on a 36-point (6 X 6) matrix held against the surface of the tongue dorsum. Precisely, (1) no electrodes were activated when both ankles were in a similar angular position within a predetermined "angular dead zone" (ADZ); (2) 12 electrodes (2 X 6) of the anterior and posterior zones of the matrix were activated (corresponding to the stimulation of the front and rear portion of the tongue) when the matching ankle was in a too plantarflexed and dorsiflexed position relative to the reference ankle, respectively. Two ADZ values of 0.5 degrees and 1.5 degrees were evaluated. Results showed (1) more accurate and more consistent matching performances with than without biofeedback and (2) more accurate and more consistent ankle joint matching performances when using the biofeedback device with the smaller ADZ valu

Low-level finite state control of knee joint in paraplegic standing

Low-level finite state (locked-unlocked) control is compared with open-loop stimulation of the knee extensor muscles in functional electrical stimulation (FES) induced paraplegic standing. The parameters were: duration of standing, relative torque loss in knee extensor muscles, knee angle stability, average stimulus output and average arm effort during standing. To investigate the impact of external mechanical conditions on controller performance, experiments were performed both under the condition of a freely moving ankle joint and of a mechanically stabilized ankle joint. Finite state control resulted in a 2.5 to 12 times increase of standing duration or in a 1.5 to 5 times decrease of relative torque loss in comparison with open-loop stimulation. Finite state control induced a limit cycle oscillation in the knee joint. Average maximum knee flexion was 6.2° without ankle bracing, and half that value with ankle bracing. Average arm support was 13.9 and 7.5% of the body weight without and with ankle bracing respectively