Low-impact Group Research Articles

Chronic Subdural Hematoma Preceded by High-Impact Trauma: Does the Intensity of Trauma Influence the Pathogenesis of Traumatic Chronic Subdural Hematoma?

The purpose of this study was to investigate whether the intensity of trauma influences the pathogenesis of traumatic chronic subdural hematoma (CSDH). Thirty-one patients treated surgically for traumatic CSDH were divided into high-impact and lowimpact groups according to the intensity of trauma. They were respectively evaluated with respect to clinical and radiological findings at presentation, and the subdural concentrations of interleukin-6 (IL-6), interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), basic fibroblast growth factor, and beta-trace protein (ΒTP) [a highly specific protein in the cerebrospinal fluid (CSF)] related to the pathogenesis of CSDH. If ΒTP (subdural fluid/serum) was > 2, an admixture of CSF to the subdural fluid was indicated. The ΒTP (subdural fluid/serum) was > 2 in all patients with a traumatic CSDH. The mean concentration of subdural ΒTP in the high-impact group was higher than in the low-impact group (6.1 mg/L versus 3.9 mg/L), and the difference was statistically significant (p=0.02). In addition, mean concentrations of IL-6, IL-8 and VEGF were higher in the high-impact group, as compared to the low-impact group, though the differences did not reach statistical significance. Trauma may be related to CSF leakage into the subdural space in CSDH, and the intensity of trauma may influence the amount of CSF leakage. Although there is no direct correlation between the amount of CSF leakage and other subdural molecules, the intensity of trauma may be associated with larger concentrations of molecules in traumatic CSDH.

The Effect of Low Impact and Mixed Impact Aerobic Exercise on Percentage of Body Fat

This study aimed to investigate the effect of low impact aerobic exercise and mixed impact aerobic exercise on lowering percentage of body fat. Many people have difficulty to stay away from overweight (obesity). It is widely known that obesity is commonly caused by over fat in the body. The populations of this research were female students of Faculty of Sport Science, Universitas Negeri Padang, while the samples were female students Department of Coaching Education. 20 female students were selected using purposive sampling technique to be the samples. Group 1 was treated with low impact aerobic exercises and group 2 was treated with mixed impact aerobic exercise. A total of 16 exercise sessions were given to the groups as treatments. The instrument used to find out the decrease of fat was Fitness Calculator. Data analysis and interpretation indicate that low impact aerobic exercise can lower body fat percentage (t=4.910, p < 0.05), mixed impact aerobic exercise can lower body fat percentage (t=5.110, p < 0.05), and there is no difference between the effect of low impact aerobic exercises and the mixed impact aerobic exercise on declining the percentage of body fat (t=1.020, p > 0.05).

Effectiveness of roundhouse kick in elite Taekwondo athletes

The roundhouse kick is a powerful attack in Taekwondo. Most athletes intently perform this kick for scoring in competition. Therefore, kinematic and kinetic analyzes of this kick were the topics of interest; however, they were separately investigated and rarely recorded for impact force. Our objectives were to investigate knee and ankle joint kinematics and electromyographic (EMG) activity of leg muscle and compare them between high-impact (HI) and low-impact (LO) kicks. Sixteen male black-belt Taekwondo athletes performed five roundhouse kicks at their maximal effort. Electrogoniometer sensors measured angular motions of ankle and knee joints. Surface EMG activities were recorded for tibialis anterior, gastrocnemius medialis, rectus femoris, and biceps femoris muscles. Based on maximal impact forces, the athletes were classified into HI and LO groups. All athletes in both groups showed greater activation of rectus femoris than other muscles. The HI group only showed significantly less plantarflexion angles than the LO group during preimpact and impact phases (P<0.05). During the impact phase, the HI group demonstrated significantly greater biceps femoris activation than the LO group (P<0.05). In conclusion, rectus femoris activation could predominantly contribute to the powerful roundhouse kicks. Moreover, high biceps femoris co-activation and optimal angle of ankle plantarflexion of about 35° could help achieve the high impact force.

Influence of exercise loading on magnetic resonance image texture of thigh soft tissues

Adaptation to exercise training can affect bone marrow adiposity; muscle-fat distribution; and muscle volume, strength and architecture. The objective of this study was to identify exercise-load-associated differences in magnetic resonance image textures of thigh soft tissues between various athlete groups and non-athletes. Ninety female athletes representing five differently loading sport types (high impact, odd impact, high magnitude, repetitive low impact and repetitive non-impact), and 20 non-athletic clinically healthy female controls underwent magnetic resonance imaging. Five thigh muscles, subcutaneous fat and femoral bone marrow were analysed with co-occurrence matrix-based quantitative texture analysis at two anatomical levels of the dominant leg. Compared with the controls thigh muscle textures differed especially in high-impact and odd-impact exercise-loading groups. However, all sports appeared to modulate muscle textures to some extent. Fat tissue was found different among the low-impact group, and bone marrow was different in the high-impact group when compared to the controls. Exercise loading was associated with textural variation in magnetic resonance images of thigh soft tissues. Texture analysis proved a potential method for detecting apparent structural differences in the muscle, fat and bone marrow.

Exercise loading and cortical bone distribution at the tibial shaft

Cortical bone is not a uniform tissue, and its apparent density [cortical volumetric density (vBMD)] varies around the bone cross-section as well as along the axial length of the bone. It is not yet known, whether the varying vBMD distribution is attributable to modulation in the predominant loads affecting bone. The aim of the present study was to compare the cortical bone mass distribution through the bone cortex (radial distribution) and around the center of mass (polar distribution) among 221 premenopausal women aged 17–40years representing athletes involved in high impact, odd impact, high magnitude, repetitive low impact, repetitive non-impact sports and leisure time physical activity (referent controls). Bone cross-sections at the tibial mid-diaphysis were assessed with pQCT. Radial and polar vBMD distributions were analyzed in three concentric cortical divisions within the cortical envelope and in four cortical sectors originating from the center of the bone cross-section. MANCOVA, including age as a covariate, revealed no significant group by division/sector interaction in either radial or polar distribution, but the mean vBMD values differed between groups (P<0.001). The high and odd-impact groups had 1.2 to 2.6% (P<0.05) lower cortical vBMD than referents, in all analyzed sectors/divisions. The repetitive, low-impact group had 0.4 to 1.0% lower (P<0.05) vBMD at the mid and outer cortical regions and at the anterior sector of the tibia. The high magnitude group had 1.2% lower BMD at the lateral sector (P<0.05). The present results generate a hypothesis that the radial and polar cortical bone vBMD distributions within the tibial mid-shaft are not modulated by exercise loading but the mean vBMD level is slightly affected.

Effects of impaction on cement mantle and trabecular bone in hip resurfacing

Failures involving the femoral part in hip resurfacing remain problematic in terms of overall implant survival. In this context, effects of impaction strength on cement mantle morphology and trabecular bone damage have not been studied to date. Sixteen paired cadaveric femora that had undergone hard and gently impacted hip resurfacing using a manual packing cementing technique in a previous study, were evaluated morphologically. The earlier study had revealed lower failure loads for hard impacted heads. A central slice of each femoral head underwent microradiography. Overall cement mantle thickness averaged 2.0 mm (range 0-5 mm) in the hard and in the low impact group with no significant difference between groups (p = 0.299). No signs of damage in the bone remnants inside the prosthesis of the fractured proximal femurs were detected in the microradiographic analysis. Cement mantle thickness was not influenced by impaction strength when using a manual packing cementing technique. No trabecular damage underneath the implant was detected despite lower failure loads, confirming the difficulty to identify small trabecular damage in an in vitro study.

Does Impaction Matter in Hip Resurfacing? A Cadaveric Study

Eight pairs of fresh frozen human femora were prepared for hip resurfacing. One side of each pair was impacted gently, the other side vigorously. After implantation procedure, specimens were loaded in a material testing machine to the ultimate fracture load. Median impaction loads on the vigorously implanted side were 11 298N compared to 1374N on the gently implanted side. Failure loads in the high-impact group (median, 8873N) were significantly ( P = .0078) reduced when compared with the low-impact group (median, 9237N). The study stresses that meticulous reaming of the femoral head and the pinhole is of tremendous importance. Remaining obstacles can lead to excessive loads, while attempting to enforce the correct seating of the implant. Only careful, slight tapping should be applied to ensure final seating.

Induction of chondrocyte apoptosis following impact load.

To investigate the presence and extent of chondrocyte apoptosis following impact load of articular cartilage in an in vivo model. An in vivo animal model, using a pendulum device and New Zealand White rabbits, was designed to study the effects of impact load on the development of chondrocyte apoptosis. Animals were placed into either a High Impact group or a Low Impact group, and the right medial femoral condyle was impacted with a single impact load. A sham operation was performed on the left limb, and this cartilage served as the control. Academic medical center. New Zealand White rabbits (3 months). Impact load to the right medial femoral condyle. Three different methods were used to assess the presence and extent of chondrocyte apoptosis: 1) light microscopy (hematoxylin and eosin and terminal dUTP nick end labeling staining); 2) transmission electron microscopy; and 3) fluorescent microscopy with Hoechst 33342 staining. Secondary outcome measures included determination of the magnitude of impact force and time to peak force. Light microscopy demonstrated chondrocytes with changes consistent with apoptosis including condensed nuclei, deep eosinophilic cytoplasmic staining, and vacuolization within the impacted specimens. Terminal dUTP nick end labeling staining-stained specimens had a high degree of positively stained cells (60%) in both injured and uninjured specimens. Transmission electron microscopy of the impacted specimens demonstrated numerous chondrocytes with changes characteristic of apoptosis, including nuclear and cellular fragmentation, volume shrinkage, and cytoplasmic vacuolization. Eleven percent of the cells in the High Impact group had changes consistent with apoptosis, versus 3% for the low impact group and <1% for the sham specimens. The High Impact group received a statistically significant greater stress than the Low Impact group. Impact group (P < 0.05), and the average time to peak force was 0.021 seconds for each impact group. The current data strongly indicate that in vivo chondrocyte apoptosis can be stimulated by the application of a single, rapid impact load and that the extent of chondrocyte apoptosis is related to the amount of load applied. The contribution chondrocyte apoptosis makes to the development of posttraumatic arthritis following joint injury or intra-articular fracture still remains to be determined.

Salivary cortisol, posttraumatic stress symptoms, and general health in the acute phase and during 9-month follow-up

Background: Because traumatic events are unpredictable, there are few studies of psychobiological states immediately following such events. Our study aimed to determine the relation of salivary cortisol to psychologic distress immediately after a traumatic event and then during follow-up. Methods: Measurement of morning and evening salivary cortisol and ratings of psychologic distress (using the Impact of Events Scale [IES], the Post Traumatic Symptom Scale, and the General Health Questionnaire) were performed with 31 United Nations soldiers at three time points—5 days and 2 and 9 months—following a mine accident in Lebanon. Results: Five days after the accident, 15 subjects reported substantial posttraumatic distress according to the IES, as well as significantly lower morning and higher evening cortisol levels compared with the low-impact group. Within 9 months, the posttraumatic distress of the high-impact group was reduced, accompanied by an increase in morning and a decrease in evening cortisol levels. There were significant relationships between evening cortisol and all rating scales at the first and third time points. Conclusions: Subclinical posttraumatic stress following an adverse event can be measured biologically via salivary cortisol levels soon after the event.

EFFECTS OF BAMBOO STEPPING EXERCISE ON MOOD STATE

AOTAKE exercise (bamboo stepping exercise) is a low-impact group exercise similar to bench stepping. It is performed to music using AOTAKE (green bamboo). The majority of studies examining aspects of psychological well-being have used exercise sessions that are at least 20 minutes in duration, with a low to moderate intensity. These studies have obtained positive results on the measurement of some psychological aspects. However, few studies have specifically focused on exercise intensity, and its conflicting results. The purpose of this study was to compare psychological measures before and after a choreographed bamboo stepping exercise session. (40 min), the subjects evaluated their mood state with an abbreviated version of the Profile of Mood Scales. Twenty-three people (15 males and 8 females, age 44.8 (yr) volunteered to serve as subjects. Statistical analysis by student t-test revealed significant differences (P < 0.05) for all variables except vigor. It is suggested that low to moderate (46, 52, and 36%VO2max for w-up, main exercise, and c-down, respectively) intensities would lead to favorable mood changes in all negative mood states (tension, anger, fatigue, depression, and confusion). This is especially important for those who are just beginning to exercise, those with poor baseline fitness, and older adults.

Does prolonged high-impact activity contribute to later urinary incontinence? A retrospective cohort study of female olympians

To determine whether women engaged in strenuous, provocative exercise are more likely to be incontinent in future life than similarly fit women who participated in less provocative exercise. In this retrospective cohort study, female American Olympians who competed in swimming (low-impact group) and in gymnastics and track and field (high-impact group) between 1960 and 1976 completed a structured questionnaire. Primary outcome measures included the prevalence of the symptoms of stress and urge incontinence. Statistical analyses of results included chi2, Fisher exact test, two-tailed t tests, Wilcoxon rank sum test, and stepwise multiple logistic regression. P < .05 was considered significant. One hundred four women responded (response rate 51.2%). High-impact athletes were older (46.2 compared with 42.4 years) and were more likely to report incontinence when they were doing their sport as Olympians (35.8% compared with 4.5%) than low-impact athletes; low-impact athletes were more likely to be parous (83.3% compared with 60.7%). There was no difference in the prevalence of the symptom of stress incontinence between the high- versus low-impact groups: any incontinence, 41.1% compared with 50%; daily or weekly incontinence, 10.7% compared with 8.3%; and incontinence that bothered them moderately or greatly, 10.7% compared with 4.2%. With our sample size, this study had 80% power to detect a fourfold difference in daily or weekly incontinence between groups, but only a 30% power to detect a twofold difference, given a baseline prevalence of 10%. When age, body mass index (BMI), parity, Olympic sport group, and incontinence during Olympic sport were entered into stepwise logistic regression analyses, only BMI was significantly associated with regular stress or urge incontinence symptoms. Participation in regular, strenuous, high-impact activity when younger did not predispose women to a markedly higher rate of clinically significant urinary incontinence in later life.