Witnessed out-of-hospital cardiac arrest- effects of emergency dispatch recognition.

BACKGROUND: Survival from an out-of-hospital cardiac arrest (OHCA) depends on the sequence of interventions in "the chain of survival". If OHCA is recognized in the emergency medical communication centre (EMCC), the proper emergency medical service (EMS) should be dispatched and cardiopulmonary resuscitation (CPR) instructions should be given to a bystander. The study aimed to examine the impact of OHCA recognition in the EMCC on survival rates and the main elements of the chain of survival. METHODS: Data from the Helsinki University Hospital's registry of OHCA patients between 1997 and 2013 were studied. Altogether, 2054 EMCC-handled and bystander-witnessed OHCA proven events of cardiac origin were analysed. RESULTS: In 80.5% of the victims, two EMS units were correctly dispatched and the OHCA was classified as recognized. Achieved return of spontaneous circulation (ROSC) and survival to hospital discharge were 49% and 23%, respectively, if cardiac arrest was recognized by the EMCC and 40% and 16% when it was not (P = 0.003 and 0.002). Dispatchers gave CPR instructions in 60% of the recognized OHCA cases. Bystander-performed CPR increased over time and was given in 58% of the recognized OHCAs and also in 17% of the unrecognized events. EMS delays were shorter if OHCA was recognized as opposed to unrecognized (8 min with an IQR 6.5-10 min vs. 9 min with an IQR 6.5-11 min; P = 0.001). CONCLUSIONS: Recognition of OHCA by the EMCC was significantly associated with an increased rate of bystander-performed CPR, reduced EMS response time, and increased OHCA patient ROSC and survival rates.

Kinetic demands of sprinting shift across the acceleration phase: Novel analysis of entire force waveforms.

A novel approach of analyzing complete ground reaction force waveforms rather than discrete kinetic variables can provide new insight to sprint biomechanics. This study aimed to understand how these waveforms are associated with better performance across entire sprint accelerations. Twenty-eight male track and field athletes (100-m personal best times: 10.88 to 11.96 seconds) volunteered to participate. Ground reaction forces produced across 24 steps were captured during repeated (two to five) maximal-effort sprints utilizing a 54-force-plate system. Force data (antero-posterior, vertical, resultant, and ratio of forces) across each contact were registered to 100% of stance and averaged for each athlete. Statistical parametric mapping (linear regression) revealed specific phases of stance where force was associated with average horizontal external power produced during that contact. Initially, antero-posterior force production during mid-late propulsion (eg, 58%-92% of stance for the second ground contact) was positively associated with average horizontal external power. As athletes progressed through acceleration, this positive association with performance shifted toward the earlier phases of contact (eg, 55%-80% of stance for the eighth and 19%-64% for the 19th ground contact). Consequently, as athletes approached maximum velocity, better athletes were more capable of attenuating the braking forces, especially in the latter parts of the eccentric phase. These unique findings demonstrate a shift in the performance determinants of acceleration from higher concentric propulsion to lower eccentric braking forces as velocity increases. This highlights the broad kinetic requirements of sprinting and the conceivable need for athletes to target improvements in different phases separately with demand-specific exercises.

Force production during maximal effort bend sprinting: Theory vs reality.

This study investigated whether the "constant limb force" hypothesis can be applied to bend sprinting on an athletics track and to understand how force production influences performance on the bend compared with the straight. Force and three-dimensional video analyses were conducted on seven competitive athletes during maximal effort sprinting on the bend (radius 37.72 m) and straight. Left step mean peak vertical and resultant force decreased significantly by 0.37 body weight (BW) and 0.21 BW, respectively, on the bend compared with the straight. Right step force production was not compromised in the same way, and some athletes demonstrated substantial increases in these variables on the bend. More inward impulse during left (39.9 ± 6.5 Ns) than right foot contact (24.7 ± 5.8 Ns) resulted in 1.6° more turning during the left step on the bend. There was a 2.3% decrease in velocity from straight to bend for both steps. The constant limb force hypothesis is not entirely valid for maximal effort sprinting on the bend. Also, the force requirements of bend sprinting are considerably different to straight-line sprinting and are asymmetrical in nature. Overall, bend-specific strength and technique training may improve performance during this portion of 200- and 400-m races.

Measurement error in estimates of sprint velocity from a laser displacement measurement device.

This study aimed to determine the measurement error associated with estimates of velocity from a laser-based device during different phases of a maximal athletic sprint. Laser-based displacement data were obtained from 10 sprinters completing a total of 89 sprints and were fitted with a fifth-order polynomial function which was differentiated to obtain instantaneous velocity data. These velocity estimates were compared against criterion high-speed video velocities at either 1, 5, 10, 30 or 50 m using a Bland-Altman analysis to assess bias and random error. Bias was highest at 1 m (+ 0.41 m/s) and tended to decrease as the measurement distance increased, with values less than + 0.10 m/s at 30 and 50 m. Random error was more consistent between distances, and reached a minimum value (±0.11 m/s) at 10 m. Laser devices offer a potentially useful time-efficient tool for assessing between-subject or between-session performance from the mid-acceleration and maximum velocity phases (i. e., at 10 m and beyond), although only differences exceeding 0.22-0.30 m/s should be considered genuine. However, laser data should not be used during the first 5 m of a sprint, and are likely of limited use for assessing within-subject variation in performance during a single session.

Modeling the stance leg in two-dimensional analyses of sprinting: inclusion of the MTP joint affects joint kinetics.

Two-dimensional analyses of sprint kinetics are commonly undertaken but often ignore the metatarsalphalangeal (MTP) joint and model the foot as a single segment. Due to the linked-segment nature of inverse dynamics analyses, the aim of this study was to investigate the effect of ignoring the MTP joint on the calculated joint kinetics at the other stance leg joints during sprinting. High-speed video and force platform data were collected from four to five trials for each of three international athletes. Resultant joint moments, powers, and net work at the stance leg joints during the first stance phase after block clearance were calculated using three different foot models. By ignoring the MTP joint, peak extensor moments at the ankle, knee, and hip were on average 35% higher (p < .05 for each athlete), 40% lower (p < .05), and 9% higher (p > .05), respectively, than those calculated with the MTP joint included. Peak ankle and knee joint powers and net work at all joints were also significantly (p < .05) different. By ignoring a genuine MTP joint plantar flexor moment, artificially high peak ankle joint moments are calculated, and these also affect the calculated joint kinetics at the knee.

Definition of the data for comprehensiveness in scenario analysis of near-surface nuclear waste repositories.

This article provides data on the near-surface repository for nuclear waste in the associated Research article "Comprehensiveness of scenarios in the safety assessment of nuclear waste repositories" [1].We illustrate i) the parameters of the COMSOL Multiphysics model for calculating the radiological impact of the repository, ii) the set of scenarios analyzed following a pluralistic approach, and iii) nodes, experts' beliefs and prior probabilities for the scenario analysis based on Bayesian networks.

Ultraviolet radiation--induced chromosomal abnormalities in fetal fibroblasts from New Zealand black mice.

Fibroblasts from New Zealand Black mouse fetuses manifest increased frequency of chromosomal breaks and interchanges after exposure to ultraviolet radiation when compared with cells from BABL/c fetuses. This chromosomal instability is similar to what has been reported in cells from patients with xeroderma pigmentosum and may be related to the chromosomally abnormal clones and malignancy previously reported in adult New Zealand Black mice.

Linkage of nicotine dependence and smoking behavior on 10q, 7q and 11p in twins with homogeneous genetic background.

The significant worldwide health burden introduced by tobacco smoking highlights the importance of studying the genetic determinants of smoking behavior and the key factor sustaining compulsive smoking, that is, nicotine dependence (ND). We have here addressed the genetic background of smoking in a special study sample of twins, harmonized for early life events and specifically ascertained for smoking from the nationwide twin cohort of the genetically unique population of Finland. The twins and their families were carefully examined for extensive phenotype profiles and a genome-wide scan was performed to identify loci behind the smoking status, ND and the comorbid phenotype of ND and alcohol use in 505 individuals from 153 families. We replicated previous linkage findings on 10q (max logarithm of the odds (LOD) 3.12) for a smoker phenotype, and on 7q and 11p (max LOD 2.50, and 2.25, respectively) for the ND phenotype. The loci linked for ND also showed evidence for linkage for the comorbid phenotype. Our study provides confirmatory evidence for the involvement of these genome regions in the genetic etiology of smoking behavior and ND and for the first time associates drinking and smoking to a shared locus on 10q.

A histological and immunohistochemical study of tissue reactions to solid poly(ortho ester) in rabbits.

In many cases only the temporary presence of a biomaterial is needed in tissue support, augmentation or replacement. In such cases biodegradable materials are better alternatives than biostable ones. At present, biodegradable polymers are widely used in the field of maxillofacial surgery as sutures, fracture fixation devices and as absorbable membranes. The most often used polymers are aliphatic polyesters, such as polyglycolic acid (PGA) and polylactic acid (PLA). Poly(ortho ester) is a surface eroding polymer, which has been under development since 1970, but is used mostly in drug delivery systems in semisolid form. The aim of this study was to evaluate the tissue reactions of solid poly(ortho ester) (POE), histologically and immunohistochemically. Resorption times and the effect of 2 different sterilization methods (gamma radiation and ethylene oxide) upon resorption were also evaluated. Material was implanted into the tibia and subcutaneously into the mandibular ramus area of 24 rabbits. Follow-up times were 1-10, 14 and 24 weeks. Histological studies showed that POE induces a moderate inflammation in soft tissue and in bone. At 24 week follow-up, inflammation was mild in soft tissue and moderate in bone. In immunohistochemical studies, no highly fluorescent layer of tenascin or fibronectin was found adjacent to the implant. Resorption of gamma-sterilized rods was faster than ethylene oxide-sterilized rods. The total resorption time was more than 24 weeks in both groups. Clinically the healing was uneventful and the implants the well tolerated by the living tissue. This encourages these authors to continue studies with this interesting new material to search for the ideal material for bone filling and fracture fixation.

Monitoring of adult B-cell lineage acute lymphoblastic leukemia: validation of a simple method for detecting immunoglobulin heavy chain gene clonality.

Most approaches to demonstrating immunoglobulin heavy chain gene rearrangements are relatively laborious for routine follow-up of acute lymphoblastic leukemia (ALL). Here the use of a simple polymerase chain reaction (PCR) approach to monitor ALL disease activity has been validated. In the dilution experiments the method revealed a detection sensitivity 0.5% clonal cells in a background of 99.5% normal cells. To validate the immunoglobulin heavy chain gene PCH (IgH-PCR) in practice, we monitored the disease activity of 26 adult ALL patients showing a B-cell lineage component in immunophenotyping at the diagnosis of the disease. In 18 of those 26 patients, an IgH-PCR product could be demonstrated in the samples taken either at diagnosis or in relapse. These 18 patients were followed with a total of 158 consecutive samples by IgH-PCR. The mean follow-up time for the IgH-PCR-positive patients was 13.6 months (range 4 to 26 months). Eleven of these patients underwent altogether 18 relapses. In nine patients (81.8%), ten relapses (55.6%) could be predicted using the IgH-PCR approach. The mean time of IgH-PCR clonality detection, preceding a cytologic relapse, was 9.1 weeks (range 1.0 to 30.7 weeks). It seems that in three patients the predictive value of the IgH-PCR was remarkable, showing a repetitive positivity in spite of a cytologic remission, even one year prior to the relapse. We find that IgH-PCR provides a straightforward additional tool for monitoring B-cell lineage ALL. Due to the straightforward technical performance the method has low running costs and it is thus suitable for a routine service laboratory. Even if a negative finding in IgH-PCR does not rule out a forthcoming relapse in the patient, a positive finding is a definitive warning signal. All of the patients that showed an IgH-PCR clonality in the follow-up samples relapsed sooner or later.

Biodegradable polydioxanone and poly(l/d)lactide implants: an experimental study on peri-implant tissue response.

Several implants for orbital wall fracture treatment are available at the present, but they have drawbacks: resorption, risk for migration and foreign body reaction. Alloplastic resorbable implants would be advantageous: no removal operation and no donor side morbidity. The purpose of this study was to evaluate the foreign body reaction, capsule formation and mechanical properties of two bioresorbable implants. PDS and SR-P(L/DL)LA mesh sheet (70/30) with solid frame (96/4) implants (SR-P(L/DL)LA 70,96) were placed into subcutaneous tissue of 24 rats. Immunohistochemistry was used to evaluate reactivity for Tn-C, alpha-actin, type I and III collagens and two mononuclear cells: T-cells and monocyte/ macrophage. GPC, DSC and SEM were performed. Student's t-test or nonparametric Kruskall-Wallis test were used for statistical analysis. Histology of peri-implant capsule exhibited an inner cell-rich zone and an outer connective tissue zone around both materials. Tn-C reactivity was high in the inner and alpha-actin in the outer zone. At the end of the study, the difference of type I collagen versus type III collagen reactivity in inner zone was statistically significant (P<0.0001) as was the difference of type I collagen versus type III collagen reactivity in outer zone (P<0.0001). Immunohistochemistry did not reveal any statistical differences of T-cell and monocyte/macrophage reactivity around PDS versus SR-P(L/DL)LA 70,96 implants, nor any differences as a function of time. PDS were deformed totally after 2 months. SR-P(L/DL)LA 70,96 implants were only slightly deformed during the follow up of 7 months. PDS degraded rapidly in SEM observation. Particles were detaching from surface. SEM observation revealed that polylactide implant was degrading from the surface and the inner porous core became visible. The degradation came visible at 7 months. There were cracks in perpendicular direction towards to the long axis of the filaments. M(w) of PDS decreased fast compared to the polylactide implant. Foreign body reaction was minimal to both materials but continued throughout the whole observation period. Mechanically PDS was poor, it looses its shape totally within 2 months. It cannot be recommended for orbital wall reconstruction. New mesh sheet-frame structure (SR-P(L/DL)LA 70,96) approved to be mechanically adequate for orbital wall reconstruction. It seems not to possess intrinsic memory and retains its shape. The resorption time is significantly longer compared to PDS and is comparable to other studied P(L/DL)LA copolymers. Thus, the new polylactide copolymer implant may support the orbital contents long enough to give way to bone growth over the wall defect.

The visibility of cancer on earlier mammograms in a population-based screening programme.

The aim of this study was to examine how frequently the later-round screen-detected and interval breast cancers were visible in earlier screening mammograms by retrospective review and to compare their radiological and clinicopathological features with those diagnosed by primary screening. In a population-based mammography screening programme 63,731 women aged 50-59 years were invited and 56,158 examinations were carried out in the period 1987-1992 in the Tampere area in Finland. A total of 276 breast cancers were detected, of which 131 were diagnosed on later screening rounds or were interval cancers. A retrospective review of previous screening mammograms was carried out in 130 cases by the radiologist who diagnosed the breast cancer and thus knew the exact location of the tumour, no blinded review was carried out. 43 (33%) cancers were visible, 84 (65%) were not visible and 3 (2%) not included on the mammogram in a retrospective review. Later round screen-detected cancers were statistically significantly more often visible in earlier screening mammograms (43%) than interval cancers (19%) (P = 0.002). Tumours missed by screening mammography but which were visible on retrospective review were often histologically well-differentiated and were more often diagnosed in the subsequent screening round than by clinical diagnosis as interval cancers. If all retrospectively visible interval cancers had been diagnosed by screening 19% (10/54) of the interval cancers could have been avoided. If all retrospectively visible cancers had been diagnosed at the time of false-negative screening or assessment 65% (84/130) of all patients would have benefitted from an earlier diagnosis compared with the actual figure of 31% (41/130).

FRAXA locus in fragile X diagnosis: family studies, prenatal diagnosis, and diagnosis of sporadic cases of mental retardation.

Three hundred eighty-seven individuals from 32 Finnish fragile X families were studied, using the probe StB12.3 [Oberlé et al., 1991: Science 252:1097-1102] for the FRAXA locus, to reveal length variations in the FMR-1 gene. As expected, the affected individuals (with few exceptions) showed a full mutation; a few affected individuals with a premutation only were found. Seventy percent of the females with a full mutation were affected. The size of the mutation remained unchanged in 6, increased in 73, and decreased in 6 female meioses. In male meioses the size was unchanged in 15 cases, increased in 2 cases, and decreased in 1 case. Prenatal diagnosis was performed in 20 cases. In 7 of these the mutation was inherited by the fetus. Four hundred sixty-four mentally retarded patients were referred to us for FRAXA analysis. In 5% of these the fragile X mutation was found. In addition to the clear cut negative or positive results there were 6 cases in which an increase of 50-80 bp was detected. These findings may represent either large normal alleles or small premutations suggesting a possible tissue mosaicism which could explain the retardation of the patients.

Terminal deletion of chromosome 4p (4p16.3) shows a breakpoint between loci linked to Huntington disease.

A 15-year-old boy with a terminal deletion of the short arm of chromosome 4 is described. The patient has a mild clinical phenotype that is incompatible with Wolf-Hirschhorn syndrome. Careful neurological examination including CT scan did not show any signs of Huntington disease. The chromosomal breakpoint was analyzed by means of polymorphic DNA probes localized close to the tentative Huntington (HD) locus. The breakage has occurred between D4S43 and D4S90 loci and thus deletes part of the chromosomal candidate regions for the HD locus.

Calcitonin gene-related peptide (CGRP) and its effects on protein release in vitro in the developing submandibular gland of the rat.

Indirect immunohistochemical methods were used to study presence and number of CGRP-immunoreactive (CGRP-IR) nerve fibers in the submandibular gland and ganglion cells of the superior cervical, submandibular and trigeminal ganglia of the developing rat. The effect of CGRP on peroxidase and total protein release was also studied in the developing postnatal submandibular glands of 1, 5, 12 and 30-day-old, as well as adult rats by in vitro methods. The possible costimulation of CGRP with SP, NKA or carbachol on 5-day-old and adult rats was also tested. The stimulatory effects of these compounds were compared to the basic release of peroxidase and total amount of proteins from submandibular gland fragments in incubation solution. CGRP-IR nerve fibers were found in relatively high number during post-natal development, mainly around blood vessels and ducts. Some CGRP-IR nerve fibers were also detected around acini. The number of these fibers was quite low and remained constant during the post-natal development. The number of CGRP-IR trigeminal ganglion cells was higher on the 5th and 12th post-natal day than later in development and in adult animals. At the same time, superior cervical- and submandibular ganglion cells were non-reactive for CGRP, suggesting trigeminal origin of CGRP-IR nerve fibers during the development in the submandibular gland. In the secretory studies, CGRP per se stimulated both peroxidase and total protein release in the submandibular gland most effectively on 5th and 12th post-natal days, while there was no clear secretory response in the adult glands. In the 5-day-old submandibular gland CGRP in combination with SP, NKA or carbachol clearly enhanced the total protein secretory response when compared with the release caused by these substances alone. However, in the adult submandibular gland, the combinations did not enhance total protein release more than any of the substances alone. Furthermore, it can be concluded that the presence of a more dense CGRP-IR innervation during the early postnatal period in the developing submandibular gland is accompanied with an increased responsiveness of the secretory elements to CGRP.

Substance P (SP) and neurokinin A (NKA) in developing submandibular glands of the rat.

The effect of isoprenaline, carbachol, substance P (SP) and neurokinin A (NKA) on peroxidase and total protein secretion was studied in the developing postnatal submandibular glands of the rat using in vitro methods. Submandibular glands of 1, 5, 12 and 30 day-old rats were stimulated by 10(-5) M isoprenaline and carbachol, and 10(-6) M SP and NKA. The stimulatory effects of these compounds were compared to the basic release of peroxidase and total amount of protein from submandibular gland fragments in incubation solution with no added transmitter substances. Indirect immunohistochemical methods were used to study these developing glands from SP- and NKA-immunoreactive (IR) nerve fibers. The distributions of SP-IR and NKA-IR nerve fibers closely resembled each other, being most abundantly spread around the developing acini and ducts. The number of these fibers was high on the 1st, 5th and 12th days, but was decreased on the 30th day. On peroxidase release, isoprenaline was the most effective, causing a maximal response of 47 times the basic release on the first postnatal day, after which it gradually decreased. The effects of carbachol, SP and NKA on peroxidase release were clearly weaker and, unlike isoprenaline, their strongest response was on the 5th postnatal day (carbachol, 4.3; SP 5.2; NKA, 4.5). The total protein secretion effect patterns of the studied substances resembled each other more, showing their strongest response on the 5th day (isoprenaline, 5.0; carbachol, 4.5; SP, 4.2; NKA, 3.4) and decreasing thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcitonin gene-related peptide immunoreactive nerve fibers in the developing salivary glands of the rat.

The appearance and distribution of calcitonin gene-related peptide immunoreactive (CGRP-IR) nerve fibers was studied by indirect immunofluorescence microscopy in the developing salivary glands of the rat at daily age intervals from the 15th day in utero (i.u.) until birth, and subsequently on the 2nd, 5th, 7th, 16th, 30th postnatal (p.n.) days. The findings were compared to samples of adult rats. CGRP-IR fibers appeared on day 20 i.u. both in parotid and submandibular glands. In submandibular glands, fibers were first seen surrounding the developing ductal branches, in the mesenchyme and also in association with developing ducts and blood vessels. In the parotid gland CGRP-IR fibers first appeared around ductal branches and blood vessels on day 20 i.u. and on day 21 i.u. CGRP-IR nerve fibers were found in the mesenchyme and around developing ducts. The density of CGRP-IR fibers was highest between the 2nd and 16th postnatal days, after which the amount of CGRP immunoreactivity slowly decreased to the levels of adult glands. The increase in a number of CGRP-IR nerve fibers especially around the ductal and vascular elements in the developing salivary glands indicates that they may play a role in the functional maturation of salivary glands.

Distribution of calcitonin gene-related peptide immunoreactive nerve fibers in the human submandibular gland.

The indirect immunofluorescence technique was used to study the distribution of calcitonin gene-related peptide (CGRP) in human submandibular gland. A relatively low number of thin varicose fibers with intense immunofluorescence for CGRP was seen in samples from seven glands. These CGRP-immunoreactive (CGRP-IR) nerve fibers were mainly seen around or in close contact with intra- and interlobular blood vessels. Some CGRP-IR nerve fibers were also found in association with intra- and interlobular salivary ducts and a few around the submandibular acini. By visual estimation there was no difference in the density of CGRP-IR nerve fibers between specimens of recurrent duct obstruction and laryngeal carcinoma. The present results show that the distribution of CGRP-IR nerve fibers in the stroma and in the glandular secretory elements of the human submandibular gland is quite similar to that seen in the rat and the ferret, which have been reported earlier. Furthermore, the regional distribution of CGRP-IR fibers in the human submandibular gland suggests that CGRP has a physiological role in the regulation of salivary gland function in human salivary glands, e.g. blood flow and secretion.

Validity of radiological examinations of patients with breast cancer in different age groups in a population based study.

By studying which radiological examinations had been performed before breast cancer operations the aim was to assess, how much benefit ultrasonography (US) and fine or core needle biopsy (FNAB, CNB) gave in addition to mammography, and whether the sensitivity of these examinations varied with the age of the patient. There were 659 consecutive histologically and six cytologically verified breast cancer cases included in the study. Information on mammography, US and FNAB findings were retrieved from the original patient files and classified as malignant or benign. The sensitivity (Se) of these was compared in three age groups (26-49, 50-59 and 60-92). Seventeen (3%) tumours had operations without any radiological examination and 73 (11%) without cytological or histological verification. The sensitivity of mammography (Se=0.92) was statistically significantly higher than the sensitivity of FNAB (Se=0.85, P=0.002) or US (Se=0.86, P=0.003). The sensitivity of mammography increased with age; US sensitivity was slightly higher amongst younger than older patients; the sensitivity of FNAB did not depend on the age of the patient. The sensitivity using a cutoff level of class 5 for mammography was higher (50% typical malignant findings) than for US (45%) or FNAB (30%). Among cases with benign mammographic finding (classes 1-2), the US finding was malignant (classes 3-5) in 4% and FNAB was malignant in 7%. Mammography is a reliable method of breast examination especially for women over 50 years of age. Ultrasonography is beneficial, particularly in younger women, but it is mainly performed as a complementary examination to a mammography and therefore could not be evaluated as an independent examination. FNAB and CNB results were not related to the age of the patient.

3-D biomechanical analysis of sprint hurdles at different competitive levels.

Four different competition sessions were examined using three-dimensional video techniques to study the hurdle clearance at different levels of performance in male and female athletes. In total, 28 trials were digitized (50 Hz) using the "Kine Analysis" software package. The Direct Linear Transformation algorithm and cross-validated quintic spline were carried out for the data. This study showed that the better female group performed with a greater take-off distance (P = 0.0006), making a lower take-off angle possible. This results in a greater horizontal velocity (P = 0.0002) than the lower level female group. Relative to the horizontal displacement of the CM from take-off to landing, the CM parabola peak occurred at 54 +/- 4% and 55 +/- 6% from take-off for the two male groups and 54 +/- 7% and 51 +/- 3% for the two female groups. There were no statistically significant differences between either the male groups or the female groups or the sexes. This would indicate that the relative peaks are at a similar point in the different parabolic paths. However, in absolute terms the peak occurred at different positions in the different groups. The reason for this is unclear and will need further investigation.