Overview One gait cycle is measured from heel-strike to heel-strike consists of stance phase period of time that the foot is on the ground ~60% of one gait cycle is spent in stance during stance, the leg accepts body weight and provides single limb support swing phase period of time that the foot is off the ground moving forward ~40% of one gait cycle is spent in swing the limb advances Stride is the distance between consecutive inital contacts of the same foot with the ground Step is the distance between initial contacts of the alternating feet Stance Phase Initial contact (heel strike) definition occurs when foot contacts the ground muscular contractions hip extensors contract to stabilize the hip quadriceps contract eccentrically tibialis anterior contracts eccentrically Loading response (initial double limb support) marks the beginning of the initial double limb stance definition occurs after initial contact until elevation of opposite limb bodyweight is transferred on to the supporting limb muscular contractions ankle dorsiflexors (tibialis anterior) contract eccentrically to control plantar flexion moment quads contract to stabilize knee and counteract the flexion moment (about the knee) Mid-stance (single limb support) initial period of single leg support definition from elevation of opposite limb until both ankles are aligned in coronal plane muscular contractions gluteus medius and calf muscles undergo eccentric contraction Terminal stance (single limb support) definition begins when the supporting heel rises from the ground and continues until the opposite heel touches the ground muscular contractions toe flexors and tibialis posterior contract and are the most active during this phase Pre-swing (second double limb support) is the start of the second double limb stance in the gait cycle definition from initial contact of opposite limb to just prior to elevation of ipsilateral limb muscular contractions hip flexors contract to propel advancing limb Swing Phase Initial swing (toe off) start of single limb support for opposite limb definition from elevation of limb to point of maximal knee flexion muscular contractions hip flexors concentrically contract to advance the swinging leg Mid-swing (foot clearance) definition following knee flexion to point where tibia is vertical muscular contractions ankle dorsiflexors contract to ensure foot clearance Terminal swing (tibia vertical) definition from point where tibia is vertical to just prior to initial contact muscular contractions hamstring muscles decelerate forward motion of thigh Variables Affected During Gait Cycle Pelvic rotation pelvis rotates 4 degrees medially (anteriorly) on swing side lengthens the limb as it prepares to accept weight Pelvic tilt pelvis drops 4 degrees on swing side lowers COG at midstance Knee flexion in stance early knee flexion (15 degrees) at heel strike lowers COG, decreasing energy expenditure also absorbs shock of heel strike Foot mechanisms ankle plantar flexion at heel strike and first part of stance Knee mechanisms at midstance, the knee extends as the ankle plantar flexes and foot supinates restores leg to original length reduces fall of pelvis at opposite heel strike Lateral displacement of pelvis pelvis shifts over stance limb COG must lie over base of support (stance limb) Center of gravity (COG) in standing position is 5cm anterior to S2 vertebral body vertical displacement during gait cycle COG displaces vertically in a rhythmic pattern the highest point is during midstance phase lowest point occurs at the time of double limb support horizontal displacement COG displaces 5cm horizontally during adult male step Muscle Activity Figure showing muscle activity through different phases of gait cycle
QUESTIONS 1 of 8 1 2 3 4 5 6 7 8 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ13.110) During which period of gait does the tibialis anterior contract eccentrically? Tested Concept QID: 4745 Type & Select Correct Answer 1 Mid-stance 10% (349/3467) 2 Heel strike 75% (2615/3467) 3 Pre-swing 6% (212/3467) 4 Initial swing 4% (138/3467) 5 Mid-swing 4% (131/3467) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review tested concept (OBQ12.237) Which phase of gait is affected most in a patient with quadriceps atrophy? Tested Concept QID: 4597 Type & Select Correct Answer 1 Terminal swing 20% (863/4418) 2 Preswing 5% (209/4418) 3 Initial swing 18% (811/4418) 4 Midstance 47% (2064/4418) 5 Midswing 10% (435/4418) L 4 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ10.123) Which of the following descriptions of muscle activity during normal gait is correct? Tested Concept QID: 3217 Type & Select Correct Answer 1 Gastrocnemius-soleus contracts eccentrically during heel strike 23% (714/3119) 2 Gastrocnemius-soleus contracts concentrically during heel strike 7% (211/3119) 3 Gastrocnemius-soleus contracts concentrically during swing phase 3% (89/3119) 4 Tibialis anterior contracts concentrically during toe-off 3% (106/3119) 5 Tibialis anterior contracts eccentrically at heel strike 63% (1977/3119) L 3 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review tested concept This is an AAOS Self Assessment Exam (SAE) question. Orthobullets was not involved in the editorial process and does not have the ability to alter the question. If you prefer to hide SAE questions, simply turn them off in your Learning Goals. (SAE07PE.54) During the early swing phase of the normal gait cycle, what lower extremity muscle is primarily contracting? Tested Concept QID: 6114 Type & Select Correct Answer 1 Tibialis posterior 2% (22/961) 2 Tibialis anterior 80% (769/961) 3 Vastus medialis 8% (76/961) 4 Adductor longus 2% (17/961) 5 Gastrocnemius 7% (72/961) L 2 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review tested concept (OBQ06.222) The primary antagonist of the anterior tibial tendon is innervated by which of the following nerves? Tested Concept QID: 233 Type & Select Correct Answer 1 Superficial peroneal nerve 57% (1629/2865) 2 Deep peroneal nerve 9% (258/2865) 3 Tibial nerve 25% (712/2865) 4 Posterior tibial nerve 8% (240/2865) 5 Sural nerve 1% (18/2865) L 3 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review tested concept
All Videos (3) Podcasts (1) Login to View Community Videos Login to View Community Videos Gait Cycle Mark Karadsheh General - Gait Cycle C 3/10/2013 6960 views 3.8 (35) Login to View Community Videos Login to View Community Videos Biomechanics of the subtalar joint Mark Karadsheh General - Gait Cycle E 3/10/2013 7107 views 3.3 (22) Login to View Community Videos Login to View Community Videos Biomechanics of the ankle Mark Karadsheh General - Gait Cycle E 3/10/2013 8145 views 2.6 (38) Foot & Ankle⎪Gait Cycle Foot & Ankle - Gait Cycle Listen Now 15:59 min 11/5/2020 94 plays 0.0 (0)