Knee Hip Extension Research Articles

Longitudinal Evaluation of Physical Fitness in Adults with Cystic Fibrosis in the Era of CFTR-Modulating-Therapies

ABSTRACT Purpose: Maintaining physical fitness plays an important role in the management of people with cystic fibrosis (pwCF). Longitudinal data on the course of physical fitness and the potential impact of the introduction of highly effective CFTR modulator therapy with elexacaftor/tezacaftor/ivacaftor (ETI) in adult pwCF are scarce. Methods: Health-related and skill-related components of physical fitness were assessed using an incremental cycle test (Wpeak), plus forward bend (FB), prone bent knee hip extension (HE), plank leg raise (PLR), standing long jump (SLJ), and standing on one leg (OLS). Relevant disease-specific clinical data (body mass index [BMI] and forced expiratory volume in 1 second [FEV1]) were recorded. Results: Twenty-eight adult pwCF (age 26.0 ± 7.8 years) were followed over 5.6 ± 0.9 years; 21 started ETI therapy during this period. Significant improvements from baseline were noted in BMI (p < 0.001) and health-related fitness components (HE, p = 0.002; PLR, p = < 0.001), whereas Wpeak and FB remained stable over time (all p > 0.05). Skill-related components (SLJ, OLS) showed no change (all p > 0.05). Subgroup analysis revealed significant improvements in BMI, FEV1, and health-related fitness measures of muscular strength and endurance (HE, p = 0.009; PLR, p < 0.001) only in pwCF using ETI. Conclusion: Despite the improvements, the impact of ETI on the individual parameters was small. Other factors than implementation of ETI alone need to be considered on the way to a high level of physical fitness in adult pwCF.

Effects Of High Intensity Aerobics and Pelvic Clock Exercises in Primary Dysmenorrhea

Dysmenorrhea is very unpleasant sensation with the presence of painful cramps of uterine origin that occur during menstruation. Prevalence rate of dysmenorrhea is 50% in females’ population. Evidence tells that inactive lifestyle as well as poor diet is main reason of primary dysmenorrheal as well as women who exercise have a reduced incidence of dysmenorrhea. Objectives: To find the effectiveness of high intensity aerobics and pelvic clock exercises in primary dysmenorrhea. Methods: The study design was randomized control trials. Purposive sampling technique was used. Girls aged 17–24 years with regular menstrual cycle and unmarried girls were included. Athletes, married women with gynecological abnormalities were excluded. A structured 8 weeks’ program (3 days in a week, 1hour per day) was given to Group A including set of London bridges (8 mins), Jumping lunges (8 mins), Mountain climbers (8 mins), Quadruped bent knee hip extension (8 mins), Warm up 10 minutes, 25 minutes for high intensity aerobics. Group B were assigned 25 minutes for Pelvic clock exercises (gradually increased during with weeks) performed from 12 to 6 o’clock, as instructed to move from 3 o clock to 9 o clock. Then movement in a clockwise manner from 12 to 3 to 6 to 9 and then back to 12 o’ clock. Outcome measures were calculated by visual analog scale VAS, DASS 21 and self-administered questionnaire for dysmenorrhea symptoms. Results: Both techniques were effective for managing the patients of pain during menstruation, but patients who were treated with high intensity aerobics exercise showed more significant result as compared to another group with p-value &lt; 0.05. Conclusions: High intensity aerobics and Pelvic clock exercises in primary dysmenorrhea, both are effective but high intensity aerobics had given more efficient results

Effects of bodyweight‐based exercise training on muscle functions of leg multi‐joint movement in elderly individuals

Because demands of functional exercise training with using own bodyweight for elderly individuals were increasing, the present study investigated the effects of bodyweight-based exercise training on muscle functions of leg multi-joint movements in elderly individuals. Twenty-seven untrained healthy elderly individuals (mean +/- standard deviation, 66.0 +/- 5.7 years) completed the training program for 10 months. The exercise program consisted mainly of exercises for large leg muscle groups without using external weight, performing 10-50 repetitions and 1-3 sets for each exercise. Before and after the training period, force-velocity relations of knee-hip extension movements were measured with a servo-controlled dynamometer and the maximum force (Fmax), velocity (Vmax) and power (Pmax) were determined. After the training, Fmax and Pmax increased and these increases represented 15% (P < 0.001) and 13% (P < 0.01) of pre-training value, respectively, while Vmax did not change. Increases in Fmax after the training were positively correlated with the initial exercise intensity determined from bodyweight (BW)/Fmax of pre-training values (P < 0.05). A training program using bodyweight can be substantially effective in improving lower limb muscle force and power in elderly individuals; however, the initial training status is important for progressive increases in muscle force.

Force–velocity, force–power relationships of bilateral and unilateral leg multi-joint movements in young and elderly women

The present study investigated force–velocity and force–power relationships of bilateral and unilateral knee-hip extension movement in young and elderly women. Twelve healthy young (age, 19–31 yr) and 12 healthy elderly (age, 60–82 yr) women performed bilateral and unilateral knee-hip extension movements on the dynamometer against loads controlled by the servo system. Under the isotonic force condition, force–velocity relationships were measured. The maximum isometric force ( F max), unloaded velocity ( V max) and power output ( P max) of the movements were calculated from extrapolating force–velocity and force–power relationships. F max and P max of bilateral and unilateral knee-hip extension movements were 20–30% lower in elderly than in young women. On the other hand, there were no significant differences in V max between young and elderly women and between bilateral and unilateral movements. Bilateral deficit was larger as the generation of force was larger in both young and elderly women. Also, bilateral deficit of F max and P max were not different between young and elderly women. The results were that lower maximum power output of bilateral and unilateral leg multi-joint movements in elderly women did not depend on the intrinsic shortening velocity of muscle action, but largely on reduction in force generating capacity. This suggests the importance of preventing a loss of force generating capacity of muscles during leg multi-joint movements in elderly women.

몸통 운동의 제약이 최대 수직점프의 수행에 미치는 영향

본 연구에서는 수직점프시 몸통운동의 제약이 수직점프의 수행에 미치는 영향을 알아보기 위해 10명의 성인 남성을 대상으로 몸통을 자유롭게 사용한 일반적인 형태와 몸통동작을 제한한 형태의 수직점프를 비교, 분석하였다. 분석 결과 몸통동작을 제한한 경우 비 제약점프에 비해 10% 정도의 수행 손실이 있었는데, 이는 이지 순간의 중심 높이보다는 이 지속도의 차이에 의해 발생하였다. 몸통의 운동은 엉덩관절의 모멘트 파워를 증가시켜 추진의 초기 시점부터 지면반력의 증가에 기여하였는데 이러한 요인이 수행력 증가의 주요한 요인으로 작용하였다. 반면 몸통운동이 제한된 점프에서는 엉덩관절에서의 역학적 출력의 감소를 보상하는 측면에서 무릎관절의 역할이 증가하였으나 충분치 못하였다. 또한 몸통동작의 제한으로 엉덩관절 무릎관절 발목관절의 순차적인 신전패턴과는 상이하게 추진시점 직후 엉덩관절과 무릎관절이 동시에 신전하는 형태의 점프가 이루어져 협응패턴의 변화가 나타났다. 결국 본 연구의 결과 몸통의 적절한 사용은 수직점프의 수행 향상에 효과적으로 기여하는 것으로 나타났다. The purpose of this study was to identify effects of restricted trunk motion on the performances of the maximum vertical jump. Ten healthy males performed normal countermovement jump(NJ) and control type of countermovement jump(CJ), in which subjects were required to restrict trunk motion as much as possible. The results showed 10% decreases of jumping height in CJ compared with NJ, which is primarily due to vertical velocity at take off. NJ with trunk motion produced significantly higher GRF than RJ, especially at the early part of propulsive phase, which resulted from increased moments on hip joint. And these were considered the main factors of performance enhancement in NJ. There were no significant differences in the mechanical outputs on knee and ankle joint between NJ and RJ. With trunk motion restricted, knee joint alternatively played a main role for propulsion, which is contrary on the normal jump that hip joint was highest contributor. And restricted trunk motion resulted in the changes of coordination pattern, knee-hip extension timing compared with normal proximal-distal sequence. In conclusion these results suggest that trunk motion is effective strategy for increasing performance of vertical jumping.

Blood pressure response to force–velocity properties of the knee-hip extension movement

This study aimed to examine the effects of maximum static and dynamic forces during and after knee-hip extension movement on blood pressure. Blood pressure was measured with a combination of oscillometric and tonometry methods before, during, immediately after and 30 s after knee-hip extension movements performed under maximum isometric and various isotonic force conditions on the servo-controlled dynamometer. The force-velocity relation of knee-hip extension movement was linear (r (2 ) = 0.9989), so that maximum isometric force (F (max)) and unloaded velocity (V (max)) were obtained by extrapolation. F (max) coincided with measured maximum isometric force (F (0)) (F (0)/F (max) = 1.03 +/- 0.25). During isometric contraction, mean arterial pressure (MAP) increased to a larger extent and the increase was significantly higher than those during all controlled-load range of isotonic force measurements. The magnitude of MAP response during maximum isometric exercise was positively correlated with both F (0) (r = 0.687, P < 0.01) and V (max) (r = 0.586, P < 0.05). On the other hand, there was no significant correlation between F (0) and V (max) (r = 0.451, P > 0.05). It is suggested that measurements of muscular function with isotonic trials cause smaller increase in blood pressure than isometric trials do. Also, it was indicated that individuals with greater muscular strength and speed might respond with larger changes in blood pressure to strenuous muscular exercises.

RELATIONS BETWEEN FORCE-VELOCITY CHARACTERISTICS OF THE KNEE-HIP EXTENSION MOVEMENT AND VERTICAL JUMP PERFORMANCE

Relations between force-velocity characteristics of the multijoint movement of the lower limbs and vertical jump performance were investigated. A total of 67 untrained subjects (age: 19.54 +/- 2.38 years; height: 166.88 +/- 8.53 cm; body mass: 59.14 +/- 10.82 kg, mean +/- SD) performed isometric and isotonic knee-hip extension movements on a servo-controlled dynamometer, and the force-velocity relations were determined. Also, vertical jump (VJ) performance was measured with a jump gauge. The force-velocity relation was described with a linear function so that the maximum isometric force (Fmax) and the maximum unloaded velocity (Vmax) for the knee-hip extension movement were estimated by extrapolation. Maximum isometric force coincided with maximum isometric force, F(0) (F(0)/Fmax = 1.03 +/- 0.24). Maximum isometric force, Vmax, and maximum power output (Pmax) were positively correlated with VJ (r = 0.48, 0.68, and 0.76, respectively; p 0.05), and significant correlations were seen between Vmax/LL and VJ (r = 0.56, p 0.05) and Fmax/BM and Vmax/LL (r = 0.05, p > 0.05) were not significantly correlated, indicating that Fmax and Vmax were independent variables. The present estimates of Fmax, Vmax, and Pmax can be useful for evaluating the actual performance of multijoint movement of the lower limbs. It is suggested that, although in untrained individuals the speed of movement might be a more important determinant of jump performance, jump performance ability has a potential to improve with increases in strength of the lower limb.

Relations Between Force-Velocity Characteristics of the Knee-Hip Extension Movement and Vertical Jump Performance

Relations between force-velocity characteristics of the multijoint movement of the lower limbs and vertical jump performance were investigated. A total of 67 untrained subjects (age: 19.54 +/- 2.38 years; height: 166.88 +/- 8.53 cm; body mass: 59.14 +/- 10.82 kg, mean +/- SD) performed isometric and isotonic knee-hip extension movements on a servo-controlled dynamometer, and the force-velocity relations were determined. Also, vertical jump (VJ) performance was measured with a jump gauge. The force-velocity relation was described with a linear function so that the maximum isometric force (Fmax) and the maximum unloaded velocity (Vmax) for the knee-hip extension movement were estimated by extrapolation. Maximum isometric force coincided with maximum isometric force, F(0) (F(0)/Fmax = 1.03 +/- 0.24). Maximum isometric force, Vmax, and maximum power output (Pmax) were positively correlated with VJ (r = 0.48, 0.68, and 0.76, respectively; p < 0.001). However, when Fmax, Vmax, and Pmax were normalized with body mass (BM), leg length (LL), and BM, respectively, no correlation was seen between Fmax/BM and VJ (r = 0.24, p > 0.05), and significant correlations were seen between Vmax/LL and VJ (r = 0.56, p < 0.001) and between Pmax/BM and VJ (r = 0.65, p < 0.001). On the other hand, Fmax and Vmax (r = 0.12, p > 0.05) and Fmax/BM and Vmax/LL (r = 0.05, p > 0.05) were not significantly correlated, indicating that Fmax and Vmax were independent variables. The present estimates of Fmax, Vmax, and Pmax can be useful for evaluating the actual performance of multijoint movement of the lower limbs. It is suggested that, although in untrained individuals the speed of movement might be a more important determinant of jump performance, jump performance ability has a potential to improve with increases in strength of the lower limb.

Steady-state force–velocity relation in human multi-joint movement determined with force clamp analysis

To study the force–velocity characteristics of human knee–hip extension movement, a dynamometer, in which force was controlled by a servo system, was developed. Seated subjects pressed either bilaterally or unilaterally a force plate, a horizontal position of which was servo-controlled so as to equalize the measured force and a force command generated by a computer at a time resolution of 2 ms (force clamp). The force command was based on the relation between maximum isometric force and foot position within the range between 70% and 90% of “leg length” (LL: longitudinal distance between the sole of the foot and the hip joint), so that the same force relative to the maximum isometric force was consistently applied regardless of the foot position. By regulating the force according to this function, the force–velocity relation was determined. The force–velocity relation obtained was described by a linear function ( n = 17 , r = - 0.986 for 80% LL, r = - 0.968 for 85% LL) within a range of force between 0.1 and 0.8 F 0 (maximum isometric force). The maximum force extrapolated from the linear regression ( F max) coincided with F 0 ( n = 17 , F 0/ F max=1.00±0.09 for 80% LL and 1.00±0.20 for 85% LL). Also, the velocity at zero force ( V max) was obtained from the extrapolation. When compared to the bilateral movements, unilateral movements gave rise to a smaller F max but the same V max, suggesting that V max is independent of force and therefore represents the proper unloaded velocity. It is suggested that some neural mechanisms may be involved in the force–velocity relation of the knee–hip extension movement, and make it exhibit a linear appearance rather than a hyperbola.

Relations Between Contractile Properties of Muscle and Acute Changes in Blood Pressure During the Knee-Hip Extension Exercise

Relations Between Contractile Properties of Muscle and Acute Changes in Blood Pressure During the Knee-Hip Extension Exercise

Effects Of Short-term Strength Training With Recumbent-type Cycle Ergometer On Muscular Function Of Lower Limbs

Evaluation of muscular function of lower limbs with a servo-controlled dynamometer (SCD) was previously reported (Yamauchi et al. 2004). PURPOSE We introduced the similar methodology to the recumbent-type cycle ergometer and investigated the effects of a 2-wk strength training with pedaling exercise on muscular function of lower limbs. METHODS 6 healthy untrained women (age, 18–27yr) were trained with pedaling exercise using a recumbent-type ergometer for 2 wk, preceded by a 2-wk of sedentary period (control). Training session consisted of 5 sets of 1 minute exercise at 30 rpm and with a 30s rest interval between sets. Intensity was 10,30,40,50 and 10% of the maximum isometric torque (Tmax) in each of 1st to 5th set for the first 7 days, thereafter increased by 10% in each set. Tmax was determined by a “stepwise loading method (S)” using an electromagnetic load control, in which the load was successively increased within a bout. The torque-velocity relation obtained with S showed no significant difference from that obtained with a conventional method, in which a varied load was applied to each bout independently. It was well described with a linear function, as previously shown in knee-hip extension movements (Yamauchi et al. 2004). The effects of training were evaluated by measuring Tmax and the extrapolated maximum unloaded rate of revolutionary (Rmax) with S. Also, the maximum isometric force (Fmax) and the unloaded velocity (Vmax) of knee-hip extension movements were measured with SCD. During knee-hip extension, EMGs were simultaneously recorded by using surface electrodes from knee-hip extensor muscles. RESULTS After initial 2-wk of sedentary period, all measured variables did not change significantly. After the training period, both Tmax and Rmax measured with the recumbent-type cycle ergometer did not change significantly, whereas both Fmax and Vmax measured with SCD increased by 9.4% and 11.2%, respectively (P<0.05, compared to pre-training values). This is consistent with the previous result on inertia-free strength training (Yamauchi et al. 2003), and suggests an improvement in muscular coordination. CONCLUSIONS Although the present training was specific to the movement for measurement (recumbent-type cycle), it failed to improve the pedaling performance. On the other hand, it caused increases in both force and velocity of the bilateral knee-hip extension, which is slightly different type of movement. Although the exact mechanism for this remains unclear, measurements using an explosive bout of movement may be more sensitive for detecting change in muscular coordination than measurements using repeated movements.

Effects Of Short-term Strength Training With Recumbent-type Cycle Ergometer On Muscular Function Of Lower Limbs

Evaluation of muscular function of lower limbs with a servo-controlled dynamometer (SCD) was previously reported (Yamauchi et al. 2004). PURPOSE We introduced the similar methodology to the recumbent-type cycle ergometer and investigated the effects of a 2-wk strength training with pedaling exercise on muscular function of lower limbs. METHODS 6 healthy untrained women (age, 18–27yr) were trained with pedaling exercise using a recumbent-type ergometer for 2 wk, preceded by a 2-wk of sedentary period (control). Training session consisted of 5 sets of 1 minute exercise at 30 rpm and with a 30s rest interval between sets. Intensity was 10,30,40,50 and 10% of the maximum isometric torque (Tmax) in each of 1st to 5th set for the first 7 days, thereafter increased by 10% in each set. Tmax was determined by a “stepwise loading method (S)” using an electromagnetic load control, in which the load was successively increased within a bout. The torque-velocity relation obtained with S showed no significant difference from that obtained with a conventional method, in which a varied load was applied to each bout independently. It was well described with a linear function, as previously shown in knee-hip extension movements (Yamauchi et al. 2004). The effects of training were evaluated by measuring Tmax and the extrapolated maximum unloaded rate of revolutionary (Rmax) with S. Also, the maximum isometric force (Fmax) and the unloaded velocity (Vmax) of knee-hip extension movements were measured with SCD. During knee-hip extension, EMGs were simultaneously recorded by using surface electrodes from knee-hip extensor muscles. RESULTS After initial 2-wk of sedentary period, all measured variables did not change significantly. After the training period, both Tmax and Rmax measured with the recumbent-type cycle ergometer did not change significantly, whereas both Fmax and Vmax measured with SCD increased by 9.4% and 11.2%, respectively (P<0.05, compared to pre-training values). This is consistent with the previous result on inertia-free strength training (Yamauchi et al. 2003), and suggests an improvement in muscular coordination. CONCLUSIONS Although the present training was specific to the movement for measurement (recumbent-type cycle), it failed to improve the pedaling performance. On the other hand, it caused increases in both force and velocity of the bilateral knee-hip extension, which is slightly different type of movement. Although the exact mechanism for this remains unclear, measurements using an explosive bout of movement may be more sensitive for detecting change in muscular coordination than measurements using repeated movements.

Effects of Muscular Coordination on The Force-Velocity Relation of Human Multi-joint Movement

2337 We have studied the force-velocity relation of human knee-hip extension movement using a newly developed servo-controlled dynamometer, and previously shown that the relation is described with a linear function more appropriately than a classical hyperbolic function (Yamauchi et al., 2003). Because the hyperbolic nature of forcevelocity relation has been shown at the crossbridge level (Ishii et al., 1997), it has been speculated that force-dependent changes in muscular coordination have a considerable effect on the nature of multi-joint movement. PURPOSE: To see how the muscular coordination affects the force-velocity relation, EMG was obtained from major working muscles during knee-hip extension movements in isometric and isotonic (force clamp) conditions. METHODS: Six healthy subjects (27 ± 5 yrs) performed knee-hip extension at their maximal effort on a servo-controlled dynamometer. EMGs were simultaneously recorded by using surface electrodes from seven muscles: vastus medialis, vastus lateralis, restus femoris, biceps femoris, semitendinosus, gluteus maximum and gastrocnemius. Also, the EMG recordings were made for maximal isometric knee extension and flexion. The EMG was full-wave rectified, integrated and averaged with respect to time (mEMG). RESULTS: In all muscles studies, mEMG did not change significantly with force in the isotonic condition. In vastus lateralis, however, it tended to decrease with increasing force, and was significantly smaller in isometric condition than in the isotonic condition (P<0.05). Also it was significantly smaller in the isometric knee extension than in the isotonic knee-hip extension. On the other hand, in a double-joint hip extensor, semitendinosus, it tended to increase with force, and was significantly larger in the isometric conditon than in the isotonic conditon. The ratio between mEMG from semitendinosus and that from vastus lateralis (ST/VL) exhibited a positive correlation with force. CONCLUSION: The coordination between knee extensor and hip extensor muscles changes with force in isotonic knee-hip extension movement. In particular, decreased activation of hip extensor relative to knee extensor under the small force may strongly affect the nature of force-velocity relation.