background: single leg drop landing is one of the common sport activities that have greater likelihood of leading to traumatic oflower extremity. however, there is limited understanding of biomechanics of this maneuver. hence, this study aimed to compare the activities of lower limb muscles during pre- and post phases of single leg drop landing. methods: this semi-experimental research of 13 ph...

guidance and control of aircraft in the landing phase imposes extra pilot work loads, hence application of automatic landing control systems is of great importance. in this study automatic landing control systems are introduced and an optimal landing control system is designed. the control system performance criteria are based on minimum control effort. the designed system is simulated for a tr...

Guidance and control of aircraft in the landing phase imposes extra pilot work loads, hence application of automatic landing control systems is of great importance. In this study automatic landing control systems are introduced and an optimal landing control system is designed. The control system performance criteria are based on minimum control effort. The designed system is simulated for a tr...

purpose: this study aimed to examine the differences in the co-activation of the rectus femoris (rf) and biceps femoris (bf) using the co-contraction index (ci) in aquatic and land environments during a drop-landing task in active and non-active females. methods: in this casual-comparison study, 10 active and 10 non-active females volunteered to participate. the ci was calculated from recorded ...

abstract introduction: identifying factors which cause the high incidence of acl is of great importance .the anterior shear forces are the primary mechanism of load sustained on the acl. during exercise, the activity of muscles and position of lower limbs may increase or decrease the anterior shear force. the purpose of this study is to investigate the relationship between the activity level of...

Guidance and control of aircraft in the landing phase imposes extra pilot work loads, hence application of automatic landing control systems is of great importance. In this study automatic landing control systems are introduced and an optimal landing control system is designed. The control system performance criteria are based on minimum control effort. The designed system is simulated for a tr...

CONTEXT Researchers have suggested that large landing forces, excessive quadriceps activity, and an erect posture during landing are risk factors for anterior cruciate ligament (ACL) injury. The influence of knee kinematics on these risk factors has been investigated extensively, but trunk positioning has received little attention. OBJECTIVE To determine the effect of trunk flexion on landing...

Background and Aims: The accurate mechanisms of ankle instability cannot be assessed in the absence of reliable knowledge about ground reaction force (GRF) variables. The purpose of this study was to evaluate the test-retest reliability of GRF variables during forward and lateral jump-landing in volleyball players with functional ankle instability (FAI). Methods: Eighteen professional volle...

abstract background and aim: lack of balance in pattern and activity of quadriceps and hamstring muscles increases the risk of anterior cruciate ligament injury (acl). the purpose of the present study was to investigate the changes in pattern and activity of vastus medialis and semitendinosusmuscles in landing from different heights and to understand if these changes will increase the risk of a...