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The Mechanics of Gait
Published in Verna Wright, Eric L. Radin, Mechanics of Human Joints, 2020
With weight totally on the limb, stability is gained by extension of the knee and hip. During the early part of midstance the vector is still posterior to the knee and ankle. Therefore, dynamic mechanisms are needed. To allow knee extension, the rate of tibial advancement is slowed by action of the soleus muscle, assisted by the gastrocnemius. Quadriceps activity draws the femur forward. This action indirectly extends the hip, allowing the hip extensor muscles to relax. As the advancing vector becomes anterior to the knee, the quadriceps relaxes as well. Critical to this process is sufficient soleus muscle action to resist the anteriorly aligned vector that is inducing passive dorsiflexion. A contracture of the plantar flexors, which stabilizes the ankle at neutral, is a useful substitute.
Visual Assessment of Postural Antecedents to Nonspecific Low Back Pain
Published in David Lesondak, Angeli Maun Akey, Fascia, Function, and Medical Applications, 2020
Approximately 25 muscles have potential effects on pelvic tilt, so a comprehensive treatment plan is not possible here. In general, those with an anterior tilted pelvis will need myofascial release or area-specific stretching for the hip flexors and the lower spinal extensors while simultaneously strengthening the abdominal wall and hip extensors. This includes the hamstrings, the adductor magnus, and the deep lateral rotator group. In addition, those with an anterior tilted pelvis often have a high and tight pelvic floor, and work with the Valsalva maneuver and generally balancing the tone of the entire “abdominal balloon” will aid in settling the pelvis back a few more degrees.
Motor and cognitive development
Published in Miguel Pérez-Pereira, Gina Conti-Ramsden, Language Development and Social Interaction in Blind Children, 2019
Miguel Pérez-Pereira, Gina Conti-Ramsden
Wyatt and Ng (1997) related the delay that blind children show in the skills of raising themselves using the arms in prone position, and crawling during infancy, with the weaker strength of knee and hip extensors that blind children show as compared to normally sighted children at 6 to 12 years of age. Wyatt and Ng suggested that the reported weakness was due to blind children’s resistance to activities in the prone position and their lack of self-initiated movements, such as crawling and standing from the crawl position, in infancy and early childhood. Activities in prone position strengthen the hip extensors as well as knee extensors.
Effects of home-based dual-hemispheric transcranial direct current stimulation combined with exercise on upper and lower limb motor performance in patients with chronic stroke
Published in Disability and Rehabilitation, 2022
Thatchaya Prathum, Pagamas Piriyaprasarth, Benchaporn Aneksan, Vimonwan Hiengkaew, Thitinat Pankhaew, Roongtiwa Vachalathiti, Wanalee Klomjai
All participants performed the exercise program immediately after the 20-min tDCS. The upper limb exercises were as follows: (1) stretching of the elbow flexor, wrist flexor, and shoulder flexor muscles (hold for 2 min/muscle group); (2) active exercise involving elbow extension, shoulder flexion, forearm pronation, and supination (10 times/set/direction, 3 sets/direction/session); (3) reach-to-grasp exercise in different directions (50 times/direction, 3 directions/session). Participants who could not move their affected arm were allowed to use their unaffected arm for assistance. Lower limb exercises were as follows: (1) stretching exercises of the hip extensor, knee flexor, and ankle plantar flexor (held for 2 min/muscle); (2) sit-to-stand exercise (10 times/set, 3 sets); (3) step forward and sideward (10 times/set/direction, 3 sets/direction).
Improvements in Hip Extensor Rate of Torque Development Influence Hip and Knee Extensor Feed-Forward Control
Published in Journal of Motor Behavior, 2021
Kristen M. Stearns-Reider, Rachel K. Straub, Christopher M. Powers
Deficits in hip strength have been proposed to contribute to the higher incidence of anterior cruciate ligament (ACL) injury observed in females (Khayambashi et al., 2016; Omi et al., 2018; Ryman Augustsson & Ageberg, 2017). Compared to males, females have been reported to exhibit decreased strength of the hip extensors and hip abductors (Claiborne et al., 2006; Jacobs et al., 2007; Stearns et al., 2013; Stearns-Reider & Powers, 2018; Willson et al., 2006). Decreased hip strength contributes to altered kinematics during single-limb squatting and landing at the hip (Claiborne et al., 2006; Crossley et al., 2011; Hollman et al., 2009), knee (Claiborne et al., 2006; Crossley et al., 2011; Suzuki et al., 2015), pelvis (Crossley et al., 2011), and trunk (Crossley et al., 2011), all of which have been shown to independently predict ACL injury (Dingenen et al., 2015; Hewett et al., 2005; Leppanen et al., 2017b, 2020; Paterno et al., 2010; Zazulak et al., 2007). In addition, decreased hip extensor strength results in greater use of the quadriceps during sport specific tasks, which has been proposed to increase strain on the ACL (Draganich & Vahey, 1990; G. Li et al., 1999; Markolf et al., 2004).
Rate of Torque Development and Feedforward Control of the Hip and Knee Extensors: Gender Differences
Published in Journal of Motor Behavior, 2018
Kristen M. Stearns-Reider, Christopher M. Powers
Previous studies investigating gender differences in RTD primarily have focused on the knee flexors and extensors. While several authors have reported that women exhibit deficits in the RTD for both the knee extensors and flexors (Bellumori, Jaric, & Knight, 2011; Ditroilo, Forte, Benelli, Gambarara, & De Vito, 2010; Zebis et al., 2011), an imbalance in the RTD of the knee flexors relative to the knee extensors has not been observed (Hannah et al., 2015; Zebis et al., 2011). More recent investigations have suggested that weakness of the hip extensors may contribute to altered landing mechanics thought to be related to increased ACL injury risk (Bien, 2011; Mendiguchia, Ford, Quatman, Alentorn-Geli, & Hewett, 2011; Pollard, Sigward, & Powers, 2010; Powers, 2010). Specifically, it has been suggested that hip extensor weakness may lead to an over-reliance on the knee extensors and the passive restraints in the frontal plane (i.e., ligaments) to absorb impact forces (Pollard et al., 2010; Powers, 2010). In support of this hypothesis, we have reported that the tendency of women to demonstrate higher knee extensor moments relative to hip extensor moments during landing may be explained, in part, by deficits in maximal isometric strength of the hip extensors relative to the knee extensors (Stearns et al., 2013). However, it is unknown if women demonstrate similar deficits in hip extensor RTD when compared with men.