Mini-Trampoline Jumping as an Exercise Intervention in Postmenopausal Women to Improve Women Specific Health Risk Factors.

BACKGROUND: Women tend to outlive men and are at higher risks of functional disability compared to men. Specifically, women are more likely to develop conditions like osteoporosis and stress urinary incontinence which can further increase the risk of functional disability. Regular physical activity and/or exercise programs can minimize the physiological decline that occurs during aging and can improve overall physical fitness, bone health, and pelvic floor muscle function; however, exercise programs tend to focus on only one parameter. Mini-trampoline jumping is a highly beneficial low-impact aerobic exercise capable of improving aerobic fitness, balance, muscle strength, and potentially bone health as well as pelvic floor muscle functioning. The aim of the proposed research project is to examine the benefits of a 3-month mini-trampoline exercise intervention on physical fitness, bone health, and pelvic floor muscle functioning in postmenopausal women. METHODS: Fifty postmenopausal healthy women aged 50-69 years will be recruited. Assessments on physical fitness (aerobic fitness, walking speed, balance, lower extremity strength, flexibility), bone health, and pelvic floor muscle functioning will occur within 1 week before and after the exercise intervention, including a 3-month follow-up assessment. The exercise intervention will last 12 weeks, with three sessions of 40 min each per week. CONCLUSIONS: The proposed research has the potential to improve functional ability and women-specific risk factors in older women with an innovative and fun exercise program.

Muscle activation and local muscular fatigue during a 12-minute rotational bridge.

Due to anecdotal reports of back pain during a 12-minute rotational bridge test by uniformed services, the level of fatigue leading to possible back pain and or injury was investigated. We hypothesised a high level of fatigue due to diminishing core muscle activation. Nineteen highly trained uniformed service members were measured by surface electromyography of the rectus abdominis, external oblique, internal oblique, lumbar erector spinae, thoracic erector spinae and latissimus dorsi. Average rectified electromyography amplitude (AEMG) and median power frequency were analysed to determine activation and fatigue. All AEMG were normalised and expressed as a percentage of maximal voluntary isometric contraction (%MVIC). Significant increases in AEMG were observed over the test duration for the rectus abdominis (+19.5%MVIC), external oblique (+18.0%MVIC) and internal oblique (+23.2%MVIC) during the prone position; and for the external oblique (+21.8%MVIC) when bracing on the measurement side (all, p < 0.05). No significant changes in median power frequency were observed (all, p > 0.05). Combining prone and side bridge positions is a reasonable measure of anterior, posterior and lateral trunk musculature. Muscular fatigue remained low throughout making this a safe assessment in trained individuals.

Lower extremity muscle function of front row rugby union scrummaging.

A rugby scrum's front row must act uniformly to transfer maximal horizontal force and improve performance. This study investigated the muscle activation patterns of lower extremity muscles in front row forwards during live and machine scrums at professional and amateur levels. Electromyography was collected bilaterally on vastus lateralis, rectus femoris and gastrocnemius muscles of 75 male rugby prop players during live and machine scrums. ANOVAs compared muscle reaction time, rate of change in muscle amplitude and muscle amplitude between groups and conditions. Cross-correlation analysis explored muscle synchronicity. There were significantly greater rates of change in each muscle amplitude in professional players than amateur players. Additionally, there was significantly quicker muscle reaction time in all muscles, and greater amplitude in vastus lateralis and gastrocnemius, during the live scrum vs. machine condition. The professional props produced more synchronised muscle activation than amateur players and all players produced more synchronised muscle activation against the scrum machine vs. live scrummage. The results indicate a higher skill proficiency and muscle synchronicity in professional players. While scrum machine training is ideally suited for functional muscle strengthening during practice, to truly simulate the requirements of the scrum, training should incorporate the live situation as much as possible.

The Effects of Uniquely-Processed Titanium on Balance and Walking Performance in Healthy Older Adults.

The increased risk of falls associated with advancing age has increased demand for methods to improve balance and mobility. The primary purpose of the study was to determine whether wearing Aqua Titan-treated stockings could improve balance and walking performance in an older population; secondary was to elucidate the mechanisms. In a randomized, double-blind crossover, 16 healthy older adults (age, 67.9 ± 4.2 years; BMI, 24.8 ± 3.1 kg/m²) performed two 4-day trials composed of baseline measures and fatiguing exercise on Day 1, with recovery measures at 14, 38 and 62 h post-exercise, wearing Aqua Titan and control stockings. Balance, walking performance, triceps surae stretch reflex, ankle range of motion and gastrocnemius muscle microvascular perfusion, blood flow and oxygen consumption were measured at baseline and during recovery. Aqua Titan had no effect on the microvascular parameters, but increased total ankle range of motion at 38 h (2.4°; 95% CI ± 1.8°) and 62 h (2.7°; ±1.7°), contributed to by increases in dorsiflexion and plantar flexion. There was decreasing persistence in the medial-lateral center of pressure movement at 38 h (q = 0, −0.0635 ± 0.0455), compared to control stockings. Aqua Titan garments hold potential for improving balance and mobility in older adults in the days following a bout of fatiguing exercise. The proposed mechanisms associated with enhanced sensory feedback require further exploration.

Electromyographic analysis of muscle activation during pull-up variations.

This study sought to identify any differences in peak muscle activation (EMGPEAK) or average rectified variable muscle activation (EMGARV) during supinated grip, pronated grip, neutral grip and rope pull-up exercises. Nineteen strength trained males (24.9±5y; 1.78±0.74m; 81.3±11.3kg; 22.7±2.5kgm-2) volunteered to participate in the study. Surface electromyography (EMG) was collected from eight shoulder-arm-forearm complex muscles. All muscle activation was expressed as a percentage of maximum voluntary isometric contraction (%MVIC). Over a full repetition, the pronated grip resulted in significantly greater EMGPEAK (60.1±22.5vs. 37.1±13.1%MVIC; P=0.004; Effect Size [ES; Cohen's d]=1.19) and EMGARV (48.0±21.2vs. 27.4±10.7%MVIC; P=0.001; ES=1.29) of the middle trapezius when compared to the neutral grip pull-up. The concentric phases of each pull-up variation resulted in significantly greater EMGARV of the brachioradialis, biceps brachii, and pectoralis major in comparison to the eccentric phases (P=<0.01). Results indicate that EMGPEAK and EMGARV of the shoulder-arm-forearm complex during complete repetitions of pull-up variants are similar despite varying hand orientations; however, differences exist between concentric and eccentric phases of each pull-up.

Wearing American Football helmets increases cervicocephalic kinaesthetic awareness in "elite" American Football players but not controls.

BACKGROUND: While there have been investigations into the reduced neck injury rate of wearing protective helmets, there is little information on its effects on normal kinaesthetic neck function. This study aims to quantify the kinaesthetic and movement effects of the American football helmet. METHODS: Fifteen British Collegiate American football players (mean age 22.2, SD 1.9; BMI kg.m(2) 26.3, SD 3.7) were age and size matched to 11 non-American football playing university students (mean age 22.5, SD 3.6; BMI 24.3, SD 3.3 kg.m(2)). Both groups had their active cervical range of motion and head repositioning accuracy measured during neck flexion/extension using a modified cervical range of motion device and a similarly modified football helmet. RESULTS: Wearing helmets significantly reduced active cervical range of motion in extension in both groups (P = 0.007 and P = 0.001 Controls and American Footballers respectively). While both groups had similar repositioning when not wearing a helmet (flexion P = 0.99; extension P = 0.52), when wearing helmets, American football players appeared to be more accurate in relation to cervical kinaesthetic repositioning (ANOVA: P = 0.077: flexion effect size =0.84; extension effect size =0.38). CONCLUSIONS: Wearing American football helmets significantly reduces the active cervical range of motion in extension, along with a change in the neutral head position. American footballers have a greater accuracy in repositioning their head from flexion (potentially enhanced proprioception) when wearing a helmet. This finding might allow development of a simple objective test to help discern presence of minor concussive or cervical musculoskeletal injury on or off the field.

Physiological, psychological and functional changes with whole body vibration exercise in the elderly: FEVER methodology and protocols.

BACKGROUND: The FEVER (Frail Elderly Vibration Exercise Response) study aims to address a paucity of research focusing on the use of Whole Body Vibration (WBV) by frail elderly who, with the highest levels of dependence and fall-related hospitalisation/mortality, potentially stand to benefit most from such accessible exercise. METHODS: FEVER is an open, randomised feasibility study, consisting of multiple parallel arms and a longitudinal element. Rest-home residents aged 70+years will be recruited, and assigned to a WBV-exercise group (WBV), a simulated-WBV-exercise group (SIM), or a control group (CON). WBV- and SIM-participants will undergo thrice-weekly sessions (<20-min each, including 1:1 ratio of exercise:rest) for a 16-week exercise intervention period, whilst CON-participants will receive no intervention beyond normal care. WBV-exercise will start with 5?1-minute sessions (6Hz, 2mm amplitude), progressing to 10?1-minute sessions at which time Hz/amplitude can be increased if desired. During WBV-exercise, participants will maintain an isometric knee flexion of ~20° (±5°), to dampen WBV further up the body. RESULTS: Outcomes will include assessments of functionality (primary outcome), Quality of Life, bone health and cardiovascular function. Measures will be conducted at baseline, 8-weeks and 16-weeks of the intervention, and 3-, 6- and 12-months post-intervention. As a protocol paper, there are no specific results to present; our current purpose is to share the study design with the scientific community. CONCLUSIONS: The FEVER study aims to investigate the beneficial effects of WBV-exercise in the frail elderly, ascertain an effective training regime and for the first-time identify a time-line of detraining.

Mass affects lower extremity muscle activity patterns in children's gait.

Overweight children demonstrate biomechanical differences during gait; however it is not known if these differences occur within active or passive tissue. The purpose of this study was to examine differences in lower extremity muscle activation patterns of children with different body mass during three walking speeds. Twenty children (8-12 years) were recruited and classified as overweight (OW), normal-weight (NW), or underweight (UW). Electromyography was recorded for vastus lateralis, semitendinosus, gastrocnemius, and tibialis anterior while participants walked on a treadmill at slow (SP), self-selected (SSP), and fast (FP) speeds. Differences in group and walking speed were analyzed for duration of muscle activation (presented as a percentage of stride, stance, or swing phases). Compared to OW, UW experienced greater duration of vastus lateralis and tibialis anterior activation during the swing phase. OW had greater duration of gastrocnemius activation during stride than UW. Increased walking speed resulted in greater duration of vastus lateralis activation for all groups. NW also exhibited greater duration of tibialis anterior activation at faster walking speeds. During FP, OW had greater duration of gastrocnemius activity during stance, but lower duration during swing. These findings are consistent with the idea that children with greater mass adopt a more passive gait strategy during swing to maximize energy recovery. Increased duration of gastrocnemius activity during stance also provides greater stability and stronger propulsion, which corroborates previous research. These findings help to understand the neuromuscular mechanisms associated with previous biomechanical findings in children's gait.

Reliability of the parallel walk test for the elderly.

OBJECTIVE: To determine interrater agreement and test-retest reliability of the parallel walk test (PWT), a simple method of measuring dynamic balance in the elderly during gait. DESIGN: Cohort study. SETTING: Outpatient clinic. PARTICIPANTS: Elderly fallers (N=34; mean ± SD age, 81.3±5.4y) registered at a falls clinic participated in this study based on Mini-Mental State Examination and Barthel Index scores. INTERVENTIONS: Subjects were timed as they walked 6m between 2 parallel lines on the floor at 3 different widths (20, 30.5, 38cm) wearing their own footwear. They were scored for foot placement on (1 point) or outside the lines (2 points) by 2 separate raters. Fifteen subjects were retested 1 week later. MAIN OUTCOME MEASURES: Footfall score and time to complete the PWT. Intraclass correlation coefficients (ICCs) and 95% limits of agreement were calculated for interrater and test-retest reliability. RESULTS: For widths of 20, 30.5, and 38cm, interrater reliability ICC range was .93 to .99 and test-retest ICC range was .63 to .90. CONCLUSIONS: The PWT was implemented easily by 2 raters with a high degree of interrater reliability. Test-retest reliability was not as high, possibly because of the high susceptibility of variation from 1 week to the next for frail elderly subjects. The 20- and 30.5-cm widths are recommended for future use of the PWT.

The effects of a rugby playing season on cervical range of motion.

Rugby players have a reduced active cervical range of motion (ACROM) mid-season compared with age-matched controls. This is most evident in rugby forwards, who have ACROM similar to patients with acute whiplash. This study aims to show if the change in ACROM over an entire rugby season (pre-, mid-, and end of season) shows a pattern of decline. A cross-sectional study of 22 rugby players (11 backs aged 24.9 +/- 1.3 years; 11 forwards aged 24.5 +/- 1.1 years) from elite English Premiership clubs had their cervical range of motion measured for flexion, extension, left and right side flexion, plus left and right rotation with a cervical range of motion device. The percentage change between start to mid-season, mid- to end of season, and start to end of season were calculated. Group means were compared for absolute ACROM (degrees) and percentage change over the season. The percentage change indicated a decrease in ACROM over the rugby playing season, with most of the decrement occurring in the second half of the season. Most of the relative change was observed in right lateral flexion, while rotation did not change significantly. In conclusion, ACROM declines throughout the playing season, which requires attention in terms of training and rehabilitation.

Validity of a functional dynamic walking test for the elderly.

OBJECTIVE: To determine the validity of a safe, quick, and simple method of measuring dynamic balance in the elderly during gait called the parallel walk test. DESIGN: Control study. SETTING: Outpatient clinic, community. PARTICIPANTS: Twenty-seven elderly fallers (age 82+/-6y) registered at a falls clinic and 34 elderly nonfallers (age 76+/-7y) were recruited to this study based on Mini Mental State Examination and Barthel Index scores. INTERVENTIONS: Subjects were timed as they walked 6m between 2 parallel lines on the floor at 3 different widths (20, 30.5, 38cm) in their own footwear. They were scored for foot placement on the line (1 point) or outside the lines (2 points). Participants also performed a timed 6-m tandem walk test, a 30-second tandem stance, and a 30-second parallel stance. MAIN OUTCOME MEASURES: Scores and time to complete the parallel walk test and tandem walk test along with the time of standing for tandem and parallel stance. Validity coefficients were calculated for the sensitivity and specificity of the parallel walk test. RESULTS: All subjects completed the parallel walk test, but few attempted and completed the tandem walk test. The fallers had significantly greater scores at 20 and 30.5cm and took significantly longer to complete the 6m at all widths. The 20-cm width was most discriminatory. The parallel walk test showed a significant correlation with the tandem stance. CONCLUSIONS: All subjects attempted and completed the parallel walk test but not the tandem walk test. The time to completion and scoring accurately measures dynamic balance during gait in elderly fallers. The parallel walk test could be a useful tool in the clinical setting for assessing balance in gait pre- and postintervention.

The effects of a single game of rugby on active cervical range of motion.

The cumulative effect of playing rugby over many years decreases active cervical range of motion, especially in the forwards. This in itself should influence long-term neck care; however, it leaves the important question of how noticeable the acute effects of active cervical range of motion are following a single game. The active cervical range of motion was measured in 21 elite rugby players (mean age 24.4 +/- 4.3 years; average professional career of 7 +/- 3.4 years) before and after a single game of rugby at the start of the season. The active cervical range of motion was recorded in flexion, extension, left and right side flexion, plus left and right rotation using a cervical range of motion device. The results show generally decreased active cervical range of motion from before to after a game independent of position played. Rugby backs had significantly (P < 0.05) reduced active cervical range of motion in flexion, while forwards were affected in extension and left lateral flexion (P < 0.05). These results highlight that a single game of rugby can reduce functional capacity of the neck (active cervical range of motion), and the affected neck movement appears to be related to the role of positional play. The authors suggest that neck training and muscle damage repair should be an important part of a rugby player's post-game recovery to limit the reduction in functional capacity.

Cervical range of motion and proprioception in rugby players versus non-rugby players.

In this study, we examined the effects of number of years of playing rugby on neck function. Active cervical spine range of motion and proprioception were assessed in 14 non-rugby-playing but trained sportsmen (mean age 28 years, s = 7) and 46 rugby players (26 rugby forwards: mean age 26 years, s = 5; mean years played 14 years; 20 backs: mean age 24 years, s = 5; mean years played 14 years). Active cervical range of motion in flexion, extension, left and right lateral flexion, plus left and right rotation were measured using a cervical range of motion device. The ability to reposition the head in a central position with eyes closed was taken as a measure of proprioception. Results show that rugby forwards generally had the least active cervical range of motion, particularly neck extension (forwards, 43 degrees ; backs, 55 degrees ; controls, 58 degrees ), with the decrement correlating with the number of years played. In addition, repositioning was significantly worse in rugby players after neck extension than non-rugby players (6 degrees vs. 3 degrees ). The active cervical range of motion of rugby forwards is similar to that of whiplash patients, suggesting that participation in rugby can have an effect on neck range of motion that is equivalent to chronic disability. Reduced active cervical range of motion could also increase the likelihood of injury and exacerbate age-related neck problems.

Knee and ankle range of motion during stepping down in elderly compared to young men.

A major factor limiting mobility in elderly subjects is their difficulty with descending steps but the physiological and biomechanical basis of this problem is not well understood. To address this question we have compared the kinematics of stepping down in six elderly male subjects and six weight- and height-matched younger subjects. Five reflective markers were positioned on the lower limbs and subjects were filmed stepping down from four heights (200, 250, 300, and 335 mm). Maximum angular displacements for the knee and ankle of the supporting limb were expressed as a percentage of each subject's passive range of motion (ROM). Time spent in 'foot flat' during single support was also compared. The results show the elderly subjects sustained dorsiflexion and a 'foot flat' position of the support limb for a significantly ( P<0.05) longer period than the young (approximately 20%). Consequently, elderly subjects utilised a greater percentage of their passive ankle ROM compared to the young (elderly approximately 200%; young approximately 125%). We conclude that the elderly maintained a 'foot flat' position for a longer period possibly to increase the time spent on a larger base of support. These results suggest that exercise prescription in the elderly should include stretching in order to increase the ROM at the ankle joint.

Joint torques and dynamic joint stiffness in elderly and young men during stepping down.

OBJECTIVE: To compare the joint torque pattern and dynamic joint stiffness at the knee and ankle in elderly and young men during stepping down. BACKGROUND: Adequate joint stiffness is critical during the single support phase to control forward and downward body momentum. DESIGN: Six active elderly men (mean 67.7) and six young men (mean 23.6) of similar body mass and height, were filmed stepping down from one force platform to another. Repeated trials were undertaken at three different step heights (200, 250, and 300 mm). METHOD: Joint torques were determined for the ankle and knee of the support limb throughout the single support phase. The gradient of the joint torque-angle graph was calculated to define dynamic joint stiffness of the ankle and knee in two phases; (I) from initiation of movement until heel-off of the supporting limb, and (II) from heel-off of the supporting limb to contra-limb touch down. RESULTS: Maximum ankle torque values were lower in the elderly and occurred at a larger dorsiflexion angle (P<0.05). Knee torque patterns were similar in both groups. Phase I ankle stiffness was significantly less in the elderly (4.0-5.2 Nm/ degrees ) at all step heights compared to the young (7.6 - 8.7 Nm/ degrees ). In both groups ankle stiffness in Phase II increased with step height, while knee joint stiffness decreased. CONCLUSIONS: The different torque pattern and lower dynamic ankle stiffness in the elderly, particularly for Phase I, suggested an altered control strategy. These findings highlight the importance of dynamic ankle joint stiffness in stepping down. RELEVANCE: Understanding how the elderly step down may be important in developing strategies to prevent falls.