Tiffany L. Grisbrook

Effect of Mulligan's and Kinesio knee taping on adolescent ballet dancers knee and hip biomechanics during landing.

Taping is often used to manage the high rate of knee injuries in ballet dancers; however, little is known about the effect of taping on lower‐limb biomechanics during ballet landings in the turnout position. This study investigated the effects of Kinesiotape (KT), Mulligans tape (MT) and no tape (NT) on knee and hip kinetics during landing in three turnout positions. The effect of taping on the esthetic execution of ballet jumps was also assessed. Eighteen pain‐free 12–15‐year‐old female ballet dancers performed ballet jumps in three turnout positions, under the three knee taping conditions. A Vicon Motion Analysis system (Vicon Oxford, Oxford, UK) and Advanced Mechanical Technology, Inc. (Watertown, Massa chusetts, USA) force plate collected lower‐limb mechanics. The results demonstrated that MT significantly reduced peak posterior knee shear forces (P = 0.025) and peak posterior (P = 0.005), medial (P = 0.022) and lateral (P = 0.014) hip shear forces compared with NT when landing in first position. KT had no effect on knee or hip forces. No significant differences existed between taping conditions in all landing positions for the esthetic measures. MT was able to reduce knee and the hip forces without affecting the esthetic performance of ballet jumps, which may have implications for preventing and managing knee injuries in ballet dancers.

The Relationship Between Landing Sound, Vertical Ground Reaction Force, and Kinematics of the Lower Limb During Drop Landings in Healthy Men

STUDY DESIGN Controlled laboratory study, cross-sectional. BACKGROUND Soft-landing instruction, which is advocated in several injury prevention programs, is thought to have a qualitative relationship with decreased vertical ground reaction forces (vGRFs) and increased lower-limb joint excursions. OBJECTIVE To quantify the relationships among landing sound, vGRFs, and lower-limb kinematics during a drop-landing task. METHODS Twenty-six asymptomatic men aged 18 to 35 years were asked to perform 15 single-leg drop landings from a 30-cm height. Five trials were collected under 3 sound conditions: normal, quiet, and loud. The vGRF, lower-limb kinematics (sagittal plane), and impact sound were recorded during the deceleration phase. RESULTS A simple linear regression revealed a significant relationship between landing sound and vGRF (R(2) = 0.42, P<.001). A repeated-measures analysis of variance showed that ankle and knee excursion significantly increased by 7.0° and 11.7°, respectively, during quiet landing (compared to normal landing; P<.001). During the loud landing condition, ankle joint excursion significantly decreased by 9.4° compared to the normal landing condition (P<.001), and hip joint excursion significantly increased by 4.0° compared to normal landing condition (P<.045). CONCLUSION As landing sound decreases, so does vGRF during a drop-landing task. These reductions were achieved by increasing ankle and knee joint excursions. Conversely, as the landing sound increases, so does vGRF. This was the result of decreasing ankle joint excursion and increasing hip joint excursion.

Alternate electrode placement for whole body and segmental bioimpedance spectroscopy.

Bioimpedance spectroscopy (BIS) is frequently used to monitor body fluid and body composition in healthy and clinical populations. BIS guidelines state that there should be no skin lesions at the site of electrodes, and if lesions are present, electrode positions should be changed. However, alternate electrode positions are yet to be reported. This study aimed to determine if ventral electrode placements were suitable alternatives for whole body and segmental BIS measurements. Three alternate electrode placements were assessed for whole body BIS using a combination of ventral hand and foot electrode placements. An alternate position was assessed for upper and lower body segmental BIS. The results demonstrated that for whole body BIS, if drive and sense electrodes on the hand are moved to ventral positions, but foot electrodes remain in standard positions, then whole body BIS variables were comparable to standard electrode positioning (percentage difference range  =  0.01 to 1.65%, p  =  0.211-0.937). The alternate electrode placement for upper limb segmental BIS, results in BIS variables that are comparable to that of the standard positioning (percentage difference range  =  0.24-3.51%, p  =  0.393-0.604). The alternate lower limb electrode position significantly altered all resistance and predicted BIS variables for whole body and lower limb segmental BIS (percentage difference range  =  1.06-12.09%, p  <  0.001). If wounds are present on the hands and/or wrist, then the alternate electrode position described in this study is valid, for whole body and upper limb segmental BIS.

Nanocrystalline silver dressings significantly influence bioimpedance spectroscopy measurements of fluid volumes in burns patients

Bioimpedance spectroscopy (BIS) is a tool utilized in health care to investigate body composition and fluid distribution. Limited research has addressed the clinical use of BIS in burns. This study aimed to examine the effects of silver dressings on BIS measurements in burns patients. BIS measurements were collected during two dressing conditions: no dressing (ND), and; Acticoat™ dressing (AD). Wilcoxon sign-ranks tests determined if there were any significant differences in BIS measures between the dressing conditions. Multilevel mixed-effects linear regressions examined the effect of %TBSA and body mass on BIS variables across the dressing conditions. The mean age of the patients (n=31) was 34.90 years; with a median TBSA of 15%. There was a significant increase in extracellular fluid (ECF) (p<0.001), intracellular fluid (ICF) (p<0.001) and total body water (TBW) (p<0.001) when AD was in place. There were significant interactions between dressing condition, %TBSA and body mass, whereby the difference in ECF, ICF and TBW between the ND and AD conditions were increased as %TBSA and body mass increased. Algorithms were developed subsequently to adjust BIS outputs for use when AD is in place. Clinicians may continue to use BIS in real-time using the predictive algorithms established during this study.

Bioimpedance spectroscopy: A technique to monitor interventions for swelling in minor burns

The control of edema in burn injured patients is a priority as it can impede the wound healing process. Bioimpedance spectroscopy (BIS) has been identified as a method of swelling assessment that has merit after burns. The aim of this study was to examine the reliability and validity of BIS in the measurement of localised burn wound edema across (1) different dressing conditions (no dressing, non silver and silver dressings) and (2) three electrode positions. BIS resistance (R) was hypothesised to be inversely proportional to fluid (edema) volume. BIS was collected in triplicate for all conditions of interest. BIS repeated measures demonstrated excellent concordance for all BIS resistance variables (R0, Ri, Rinf) (intraclass correlation coefficient=0.999-1.00, 95% confidence intervals 0.999-1.00) without a systematic difference. Multilevel mixed effects linear regression analysis examined the effect of electrode position and dressing condition on BIS resistance variables. R0, Ri and Rinf significantly increased with decreasing localised limb segment volume (p≤0.01). Resistance was significantly (1) reduced when a silver dressing was in situ (p<0.01) and (2) increased when a non-silver dressing was insitu (p<0.01). There was a significant interaction between each dressing condition and localised limb segment volume (p<0.01). An algorithm was developed to adjust resistance values when a silver dressing is in use. BIS may be used clinically to monitor localised changes in burn wound edema.

Running quietly reduces ground reaction force and vertical loading rate and alters foot strike technique

ABSTRACT This study aimed to determine if a quantifiable relationship exists between the peak sound amplitude and peak vertical ground reaction force (vGRF) and vertical loading rate during running. It also investigated whether differences in peak sound amplitude, contact time, lower limb kinematics, kinetics and foot strike technique existed when participants were verbally instructed to run quietly compared to their normal running. A total of 26 males completed running trials for two sound conditions: normal running and quiet running. Simple linear regressions revealed no significant relationships between impact sound and peak vGRF in the normal and quiet conditions and vertical loading rate in the normal condition. t-Tests revealed significant within-subject decreases in peak sound, peak vGRF and vertical loading rate during the quiet compared to the normal running condition. During the normal running condition, 15.4% of participants utilised a non-rearfoot strike technique compared to 76.9% in the quiet condition, which was corroborated by an increased ankle plantarflexion angle at initial contact. This study demonstrated that quieter impact sound is not directly associated with a lower peak vGRF or vertical loading rate. However, given the instructions to run quietly, participants effectively reduced peak impact sound, peak vGRF and vertical loading rate.

Hip adduction and abduction strength profiles in elite, sub-elite and amateur Australian footballers

OBJECTIVES It has been reported that obtaining an adduction-to-abduction strength ratio of 90-100%, and an adduction strength equal to that of the uninjured side, are suitable clinical milestones for return to sport following groin injury. Little is known about hip adduction and abduction strength profiles in Australian footballers. This study aimed to compare isometric hip adduction and abduction strength profiles between preferred and non-preferred kicking legs in elite, sub-elite and amateur Australian footballers. DESIGN Cross sectional study METHODS 36 elite, 19 sub-elite and 18 amateur Australian footballers, with a mean age of 24, 19 and 23 years respectively, were included. Maximal hip isometric adduction and abduction strength were measured using a hand held dynamometer with external belt fixation. RESULTS There were no significant differences in isometric hip adduction (p=0.262) or abduction (p=0.934) strength, or the adduction-to-abduction ratio (p=0.163), between preferred and non-preferred kicking legs, regardless of playing level. Elite players had significantly greater isometric hip adduction and abduction strength than both sub-elite (mean difference; adduction=46.01N, p<0.001, abduction=30.79N, p=0.003) and amateur players (mean difference; adduction=78.72N, p<0.001, abduction=59.11N, p<0.001). There was no significant difference in the adduction-to-abduction ratio between the playing levels (p=0.165). CONCLUSIONS No significant differences were found between preferred and non-preferred kicking legs across the playing levels for isometric hip adduction, abduction or the adduction-to-abduction ratio. This may have implications for developing groin injury prediction and return to sport criteria in Australian footballers.

Addressing the Barriers to Bioimpedance Spectroscopy Use in Major Burns: Alternate Electrode Placement

Bioimpedance spectroscopy (BIS) is a method used to assess body composition and fluid distribution. As a technology for measurement of fluid shifts during acute burn resuscitation, there are potential barriers to its use due to the location of wounds. This study aimed to determine whether alternate electrode positions were a suitable alternative compared to standardized (manufacturer) positions in moderate to large size burns for the measurement of BIS resistance and fluid changes. BIS measurements were collected in standard and alternate electrode placements and in an open wound and Acticoat™ dressing condition. A percentage difference greater than 5% between each standard and alternate placement BIS measurements was deemed clinically significant. Chi-square tests determined there were no significant differences (P = .097–.96) between the standard and alternate electrode placements for whole body and limb segment BIS in both dressing conditions. Only whole body BIS resistance variables and extracellular fluid volumes were interchangeable in both dressing conditions and upper limb segmental measures were interchangeable in an open wound only. The differences between measurements of other BIS variables across the conditions were not acceptable or deemed not clinically acceptable without adjustment. The results showed that for moderate to large burn injuries clinicians can use whole body and upper limb segmental BIS variables to monitor changes in fluid shifts with alternate electrode placements where wounds preclude standardized placement within specified dressing conditions.

Predicting 1 Repetition Maximum Using Handheld Dynamometry

Isometric assessment of muscular function using a handheld dynamometer (HHD) is frequently used in clinic environments. However, there is controversy in terms of the validity of isometric assessment to monitor changes in dynamic performance. One repetition maximum (1RM) is considered the gold standard for evaluating dynamic strength, though clinicians do not often use 1RM testing, preferring to be cautious with clients who have preexisting impairments. If strength testing using an HHD could be used to predict 1RM, this may have significant implications for the use of isometric testing to prescribe exercise in clinical environments.

The effectiveness of session rating of perceived exertion to monitor resistance training load in acute burns patients.

Session-rating of perceived exertion (RPE) is a method frequently utilised in exercise and sports science to quantify training load of an entire aerobic exercise session. It has also been demonstrated that session-RPE is a valid and reliable method to quantify training load during resistance exercise, in healthy and athletic populations. This study aimed to investigate the effectiveness of session-RPE as a method to quantify exercise intensity during resistance training in patients with acute burns. Twenty burns patients (mean age=31.65 (±10.09) years), with a mean TBSA of 16.4% (range=6-40%) were recruited for this study. Patients were randomly allocated to the resistance training (n=10) or control group (n=10). All patients completed a four week resistance training programme. Training load (session-RPE×session duration), resistance training session-volume and pre-exercise pain were recorded for each exercise session. The influence of; age, gender, %TBSA, exercise group (resistance training vs. control), pre-exercise pain, resistance training history and session-volume on training load were analysed using a multilevel mixed-effects linear regression. Session-volume did not influence training load in the final regression model, however training load was significantly greater in the resistance training group, compared with the control group (p<0.001). Pre-exercise pain significantly influenced training load, where increasing pain was associated with a higher session-RPE (p=0.004). Further research is indicated to determine the exact relationship between pain, resistance training history, exercise intensity and session-RPE and training load before it can be used as a method to monitor and prescribe resistance training load in acute burns patients.