Knee extensor muscle strength and vertical jumping performance characteristics were compared between 14 pre-pubertal (11-year-old) and post-pubertal (16-year-old) boys. Post-pubertal boys had greater (p < .05) absolute values of maximal isometric force (MF) and rate of force development (RFD), absolute and body mass-related values of isokinetic peak torque of the knee extensor muscles at angular velocities of 60, 180, and 240° · s−1, as well as jumping height in squat, counter-movement, and drop jumps, than pre-pubertal boys. This study indicated an inability to use the positive effect of stretch-shortening cycle to vertical jumping performance in pre- and post-pubertal boys.
Mati Pääsuke, Jaan Ereline and Helena Gapeyeva
Viire Talts, Jaan Ereline, Tatjana Kums, Mati Pääsuke and Helena Gapeyeva
Our aim with the current study was to compare upper extremity and cue kinematics, and electromyographic (EMG) activation of shoulder muscles during novus (a special form of billiards) shots of different difficulty levels. Ten proficient and 10 less-skilled novus players performed 3 types of novus shots (penalties, cuts, rebounds) 10 times each. During each shot, elbow flexion and cue–forearm angles (using a movement analysis system), and surface EMG activity of the trapezius, posterior, and lateral deltoid muscles of each subject’s dominant side, were measured. Data were compared between more- and less-skilled players, and successful compared with unsuccessful shots. Elbow flexion angle among the more-skilled players was 24.5% larger (P < .001) during unsuccessful cut shots than successful ones. The more-skilled players performed successful penalty and rebound shots with 26.8% and 49.8% lower (P < .01 and P < .001, respectively) EMG activity of the trapezius muscle than unsuccessful ones. Less-skilled players’ shots were characterized by higher EMG activity in the trapezius muscle. The obtained findings suggest that the more-skilled novus players had acquired a different muscle recruitment pattern than less-skilled players.
Bernardo Requena, Jaan Ereline, Helena Gapeyeva and Mati Pääsuke
The understanding of posttetanic potentiation (PTP) in human muscles induced by percutaneous electrical stimulation (PES) is important for effective application of electrical stimulation in rehabilitation.
To examine the effect of 7-second high-frequency (100-Hz) submaximal (25% of maximal voluntary contraction force) direct PES on contractile characteristics of the knee-extensor (KE) muscles.
Single-group repeated measures.
13 healthy men age 18–27 years.
Peak force (PF), maximal rates of force development (RFD) and relaxation (RR) of supramaximal twitch, and PF of doublet and 10-Hz tetanic contractions before and after direct tetanic PES.
A significant potentiation of twitch, doublet, and 10-Hz tetanic-contraction PF has been observed at 1–5 minutes posttetanic. Twitch RFD and RR were markedly potentiated throughout the 10-minute posttetanic period.
A brief high-frequency submaximal tetanic PES induces PTP in KE muscles associated with small increase at 1–5 minutes.
Mati Pääsuke, Jaan Ereline, Helena Gapeyeva, Madli Toots and Laivi Toots
Twitch contractile properties of plantar flexor muscles were compared in 9- to 10-year-old girls and boys. No significant gender differences (p > .05) in isometric maximal voluntary contraction force and twitch peak force, contraction and relaxation times, and twitch maximal rate of force development in either resting or potentiated state have been observed. However, boys had significantly greater (p < .05) twitch postactivation potentiation and potentiated twitch maximal rate of relaxation than girls. These results indicated that twitch force-potentiation capacity of skeletal muscles prior to puberty is more highly developed in boys than girls.
Mati Pääsuke, Jaan Ereline, Helena Gapeyeva and Heigo Maamägi
This study compared maximal voluntary-contraction (MVC) force and twitch-contractile properties of the plantar-flexor muscles in resting and postactivation potentiation slates of 2 groups of men matched for similar levels of physical activity: young (19- to 22-year-olds. n = 13) and 52–63 years old (n = 12). MVC force, twitch peak force (PT), maximal rates of force development and relaxation, and postactivation potentiation were higher (p < .05) in young than in 52- to 63-year-old men. In young men. potentiated-twitch PT was 23.3% higher (p < .01) than resting twitch. Resting- and potentialed-twitch-contraction times were 16.7% and 18.3% shorter, respectively (p < .001), in young than in 52- to 63-year-old men. These Findings suggest that late middle age is characterized by reduced capacity for evoked twitch-force generation and potentiation and slowed speed of contraction of the plantar-flexor muscles.
Karin Tammik, Mariann Matlep, Jaan Ereline, Helena Gapeyeva and Mati Pääsuke
Isometric voluntary force production and relaxation capacity of the quadriceps femoris (QF) muscle was compared between 12 children with spastic diplegic cerebral palsy (CP) and healthy controls, age 10–11 years. Children with CP had less (p < .05) maximal voluntary-contraction force, voluntary activation, and rate of force development than controls. Visual reaction to contraction did not differ significantly in measured groups, whereas the reaction time to relaxation and halfrelaxation time were longer (p < .05) in children with CP. The authors concluded that in children with CP, the capacity for rapid voluntary force production and relaxation is reduced to a greater extent than isometric maximal force.
Anni Rava, Anu Pihlak, Jaan Ereline, Helena Gapeyeva, Tatjana Kums, Priit Purge, Jaak Jürimäe and Mati Pääsuke
The purpose of this study was to evaluate the differences in body composition, neuromuscular performance, and mobility in healthy, regularly exercising and inactive older women, and examine the relationship between skeletal muscle indices and mobility. Overall, 32 healthy older women participated. They were divided into groups according to their physical activity history as regularly exercising (n = 22) and inactive (n = 10) women. Body composition, hand grip strength, leg extensor muscle strength, rapid force development, power output, and mobility indices were assessed. Regularly exercising women had lower fat mass and higher values for leg extensor muscle strength and muscle quality, and also for mobility. Leg extensor muscle strength and power output during vertical jumping and appendicular lean mass per unit of body mass were associated with mobility in healthy older women. It was concluded that long-term regular exercising may have beneficial effects on body composition and physical function in older women.
Mati Pääsuke, Jaan Ereline, Helena Gapeyeva, Kadri Joost, Karin Mõttus and Pille Taba
The lower extremity performance in elderly female patients with mild to moderate Parkinson’s disease (PD; n = 12) and controls (n = 16) was compared. Isometric dynamometry and force-plate measurements were used. PD patients had lower (p < .05) bilateral (BL) maximal isometric leg-extension force (MF), BL isometric MF relative to body mass, and maximal rate of isometric force development than control participants. BL strength deficit was greater (p < .05) in PD patients than in controls. A significantly longer chair-rise time and lower maximal rate of vertical-ground-reaction-force development while rising from a chair was found in PD patients than in controls. These findings suggest that elderly women with PD have lowered voluntary isometric force-generation capacity of the leg-extensor muscles. Reduced BL leg-extension strength might contribute to the difficulty of individuals with PD to rise from a chair.
Helena Gapeyeva, Mati Pääsuke, Jaan Ereline, Vallo Vaher, Aivar Pintsaar and Aalo Eller
Contractile characteristics of the knee extensors after arthroscopic meniscectomy are poorly understood.
To measure the recovery of knee-extensor-muscle contractility after arthroscopic partial meniscectomy.
Single-group repeated measures.
Kinesiology and biomechanics laboratory.
Fourteen patients with arthroscopic partial medial meniscectomies.
Main Outcome Measures:
Maximal isometric voluntary contraction (MVC) force, rate of force development (MRFDES), and half-relaxation time (HRTES) of evoked tetanic contraction preoperatively and during 6 months postoperatively.
Two weeks postoperatively, a reduction in MVC force of 27.1% and in MRFDES of 17.8% and a prolongation of HRTES of 34.0% in the injured leg were found. A significant MVC-force deficit (17.5%) was observed 3 months postoperatively.
The recovery of knee-extensor-muscle voluntary strength is more delayed than are evoked tetanic-contractile characteristics after partial meniscectomy. The rehabilitation protocol seems to be insufficient to attain effective recovery of knee-extensor-muscle voluntary strength.