0000000000345543
AUTHOR
Jarmo Perttunen
showing 15 related works from this author
Improvements in functional capacity from Nordic walking: a randomized-controlled trial among elderly people.
2011
This study examined the effects of an instructed structured Nordic walking (NW) exercise program on the functional capacity of older sedentary people. Volunteers were randomly assigned to an NW group (68.2 ± 3.8 yr old) or control group (69.9 ± 3.0 yr old). Before and at the end of the 9-wk intervention, functional tests and 2-dimensional ground-reaction-force (GRF) patterns of normal (1.40 m/s) and fast (1.94 m/s) walking speeds were measured. The intervention included a 60-min supervised NW session on an inside track twice a week for 9 wk. The mean changes in functional tests differed between groups significantly. Gait analyses showed no significant differences between the groups on any G…
EMG activities and plantar pressures during ski jumping take-off on three different sized hills
2001
Different profiles of ski jumping hills have been assumed to make the initiation of take-off difficult especially when moving from one hill to another. Neuromuscular adaptation of ski jumpers to the different jumping hills was examined by measuring muscle activation and plantar pressure of the primary take-off muscles on three different sized hills. Two young ski jumpers volunteered as subjects and they performed several trials from each hill (K-35 m, K-65 m and K-90 m) with the same electromyographic (EMG) electrode and insole pressure transducer set-up. The results showed that the differences in plantar pressure and EMGs between the jumping hills were smaller than expected for both jumper…
Predictors of lower extremity injuries in team sports (PROFITS-study): a study protocol.
2015
Introduction Several intrinsic risk factors for lower extremity injuries have been proposed, including lack of proper knee and body control during landings and cutting manoeuvres, low muscular strength, reduced balance and increased ligament laxity, but there are still many unanswered questions. The overall aim of this research project is to investigate anatomical, biomechanical, neuromuscular, genetic and demographic risk factors for traumatic non-contact lower extremity injuries in young team sport athletes. Furthermore, the research project aims to develop clinically oriented screening tools for predicting future injury risk. Methods Young female and male players (n=508) from nine basket…
Knee Control and Jump-Landing Technique in Young Basketball and Floorball Players
2015
Poor knee alignment is associated with increased loading of the joints, ligaments and tendons, and may increase the risk of injury. The study purpose was to compare differences in knee kinematics between basketball and floorball players during a vertical drop jump (VDJ) task. We wanted to investigate whether basketball players, whose sport includes frequent jump-landings, exhibited better knee control compared with floorball players, whose sport involves less jumping. Complete data was obtained from 173 basketball and 141 floorball players. Peak knee valgus and flexion angles during the VDJ were analyzed by 3D motion analysis.Larger knee valgus angles were observed among basketball players …
Asymmetry of gait after free flap reconstruction of severe tibial fractures with extensive soft-tissue damage.
2000
Gait patterns of the preferred speed were investigated on 17 patients recovering (9 months-14 years) after reconstruction of severe tibial fractures. A novel data-acquisition system was used to record the plantar pressures as well as electromyographic (EMG) activities during walking. The results indicated incomplete recovery of symmetrical gait patterns. In particular, the duration of the stance phase was shorter on the operated side (mean (SD) 701 (90) ms compared with 765 (128) ms, p < 0.001). The peak pressure points under the foot were different on bilateral comparison, the operated side being regularly higher under the lateral forefoot area. This may imply attempts to reduce the loadin…
Gait asymmetry in patients with limb length discrepancy.
2004
Foot loading patterns and neuromuscular function of both limbs during walking were investigated on 25 patients with limb length discrepancy. Plantar pressures and 2-D ground reaction forces were recorded simultaneously with electromyographic activities at two different walking speeds. Bilateral comparison indicated that moderate limb length discrepancies resulted in asymmetrical gait patterns. The duration of the stance phase was reduced in the short limb in both walking speeds. The vertical ground reaction force (F) in the push-off phase was greater in the long limb both at normal (1.33 (SO, 0.05 BW) vs. 1.29 (SD, 0.09 BW)) (P=0.0027) and fast walking speed (1.55 (SD, 0.11) vs. 1.48 (SD, 0…
Sagittal Plane Hip, Knee, and Ankle Biomechanics and the Risk of Anterior Cruciate Ligament Injury: A Prospective Study
2018
Background: Stiff landings with less knee flexion and high vertical ground-reaction forces have been shown to be associated with an increased risk of anterior cruciate ligament (ACL) injury. The literature on the association between other sagittal plane measures and the risk of ACL injuries with a prospective study design is lacking. Purpose: To investigate the relationship between selected sagittal plane hip, knee, and ankle biomechanics and the risk of ACL injury in young female team-sport athletes. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 171 female basketball and floorball athletes (age range, 12-21 years) participated in a vertical drop jump test usin…
Loading and gait symmetry during level and stair walking in asymptomatic subjects with knee osteoarthritis: importance of quadriceps femoris in reduc…
2007
Repetitive impulsive forces during walking are claimed to result in joint osteoarthritis (OA). The aim of this study was to investigate impact loading and gait symmetry during level and stair walking in asymptomatic elderly subjects with knee OA. It was hypothesised that pre-activity of the quadriceps femoris muscle (QF) would be an important factor reducing impulsive loading when walking on level ground. Subjects [21 female, six men, 66.2 (7.6) years] were studied. The subjects had no knee pain or diminished functional capacity, but showed radiographically light or moderate bilateral knee OA changes. Ground reaction forces (GRFs), plantar pressure distribution, muscle activation pattern [v…
Association between frontal plane knee control and lower extremity injuries : a prospective study on young team sport athletes
2017
Background/aimPoor frontal plane knee control can manifest as increased dynamic knee valgus during athletic tasks. The purpose of this study was to investigate the association between frontal plane knee control and the risk of acute lower extremity injuries. In addition, we wanted to study if the single-leg squat (SLS) test can be used as a screening tool to identify athletes with an increased injury risk.MethodsA total of 306 basketball and floorball players participated in the baseline SLS test and a 12-month injury registration follow-up. Acute lower extremity time-loss injuries were registered. Frontal plane knee projection angles (FPKPA) during the SLS were calculated using a two-dimen…
Biomechanical loading in the triple jump
2000
The triple jump is a demanding field event in which a jumper must tolerate extremely high impact forces while maintaining high horizontal speed. The present study was designed to clarify the mechanical loading characteristics and the role of neuromuscular function in the triple jump. Seven national triple jumpers (4 males, 3 females) volunteered to perform 3-6 jumps. The mean best performances were 14.32+/-0.45 m and 11.90+/-0.28 m for males and females, respectively. The three longest triple jumps for each jumper were selected for final analysis. The mean contact times were 0.139 s (hop), 0.157 s (step) and 0.177 s (jump). The largest ground reaction forces were observed in the step (15.2 …
Stiff landings are associated with increased ACL injury risk in young female basketball and floorball players
2016
Background: Few prospective studies have investigated the biomechanical risk factors of anterior cruciate ligament (ACL) injury. Purpose: To investigate the relationship between biomechanical characteristics of vertical drop jump (VDJ) performance and the risk of ACL injury in young female basketball and floorball players. Study Design: Cohort study; Level of evidence, 3. Methods: At baseline, a total of 171 female basketball and floorball players (age range, 12-21 years) participated in a VDJ test using 3-dimensional motion analysis. The following biomechanical variables were analyzed: (1) knee valgus angle at initial contact (IC), (2) peak knee abduction moment, (3) knee flexion angle at …
973 Knee control and jump-landing technique in young basketball and floorball players
2016
Background Poor knee alignment is associated with increased loading of the joints, ligaments and tendons, and may increase the risk of injury. The study purpose was to compare differences in knee kinematics between basketball and floorball players during a vertical drop jump (VDJ) task. We wanted to investigate whether basketball players, whose sport includes frequent jump-landings, exhibited better knee control compared with floorball players, whose sport involves less jumping. Methods Players (aged 12–21 years) were recruited from six basketball and floorball clubs of the Tampere City district, Finland. Complete data was obtained from 173 basketball and 141 floorball players. Peak knee va…
Mineral mass, size, and estimated mechanical strength of triple jumpers’ lower limb
2001
This study was designed to examine the anticipated strong influence of extreme impact loading on the mineral mass, size, and gross structural properties of triple jumpers' lower limb bones. We compared the bone data obtained with peripheral quantitative computed tomography (pQCT) and dual-energy X-ray absorptiometry (DXA) from 8 Finnish triple jumpers with corresponding data from gender-, age-, height-, and weight-matched nonathletic peers. The volumetric (trabecular) density was significantly higher in the jumpers than in controls (from an average 18% difference at the distal tibia to a 41% difference at the proximal tibia), whereas the cortical density did not differ between groups. The D…
Effect of intramedullary gradual elongation of the shorter limb on gait patterns
2003
Background: Seven young patients were followed 52 weeks after intramedullary lengthening for limb length discrepancy (LLD). The mean LLD before surgery was 3.0 ± 1.1 cm and 1 year after surgery at the time of the nail-removal it was 0.3 ± 0.3 cm. Methods: The plantar pressures and the ground reaction forces (GRF) were recorded simultaneously with electromyographic (EMG) activities at normal and fast walking speeds. Results: Bilateral comparison indicated that the uncorrected LLD resulted in asymmetrical gait patterns. The peak pressures were higher in the lateral heel and in the medial forefoot in the longer limb as compared to the shorter limb at normal walking speed. At fast walking speed…
Foot loading in normal and pathological walking
2002
Perusteellinen kävely- ja kuormitusanalyysi on usein tarpeellinen jalkaongelmissa, jotta mahdollinen tukien ja ortoosien valinta sekä alaraajoihin kohdistuvien leikkausten jälkeinen kuntoutus pystytään suorittamaan parhaalla mahdollisella tavalla, toteaa Jarmo Perttunen väitöstutkimuksessaan. Kävelijä tuottaa tukivaiheen aikana alustaan voimia pysty- ja vaakasuunnassa, joita on perinteisesti mitattu voimalevyantureilla. Ne eivät pysty yksistään erottelemaan kuormitusta jalkapohjan eri osien välillä riittävän täsmällisesti. Kiinnostus selvittää kuormitus tarkasti on johtanut kehityksen alkeellisista jalkapohjan mustekuvista hyvin pieniin kengän sisälle asetettaviin mittausantureihin. Perttus…