The purpose of this study is to determine if adult survivors of childhood Acute Lymphoblastic Leukemia (ALL) enrolled on the SJLife (St. Jude Life) protocol are at increased risk for postural control deficits compared to individuals with no cancer history. All participants will be assessed for their ability to maintain an upright posture, walk at their usual speed, and to tandem walk, all while engaged in a cognitive task.

Primary Objective

To compare changes in postural control in ALL survivors to changes in postural control in healthy controls, matched on age- and sex- in simple versus complex standing and walking activities (complex: standing or walking with added cognitive load).

Secondary Objective

To identify demographic and performance related risk factors for decreased postural control during complex standing or walking activities in survivors and controls and to evaluate associations between treatment and the changes in postural control during complex activities among survivors.

Cognitive performance (attention and working memory) will be evaluated using the auditory N-Back test. The 0-back condition and the 2-back condition will be used. After cognitive assessment, participants will perform 3 different postural control tasks (standing balance, regular gait, and tandem gait) in a random order. Postural tasks for each participant will be determined by using random allocation envelopes.

Computerized dynamic posturography will be used to evaluate standing balance with no added cognitive load. Standing balance assessment will be repeated two more times, once with participants engaged in performing the auditory 0-back task, and then with simultaneously performing the auditory 2-back task. Regular gait at participants' preferred speed will be examined using 6 light-weight wearable inertial sensors. The regular walking assessment will be repeated with simultaneous performance of the 0-back task and then with simultaneous engagement in the 2-back task. We have also included a tandem gait (placing one foot directly in front of the other) in order to make the postural task more challenging. The wearable inertial sensors will be used to record participants' gait characteristics while tandem walking. The tandem walk assessment will be repeated once with the participant simultaneously perform the 0-back task and then with the 2-back task. The estimated required time to perform all of the assessments and with inclusion of 3 rest intervals is 2 hours.

In addition, data from the overall SJLIFE assessment will be used in analysis.

Inclusion Criteria - Cases:

• Diagnosis of childhood ALL
• At least 5 years post ALL diagnosis
• No history of secondary malignancies after an ALL diagnosis
• Enrollment on the SJLIFE protocol
• Ages 18.00 to 39.99
• Ability to stand and walk for 20 seconds or more
• Ability to answer the eligibility questions
• Ability to provide informed consent

Inclusion Criteria - Controls:

• No history of childhood or adult onset cancer
• Enrollment on the SJLIFE protocol
• Ages 18.00 to 39.99
• Ability to stand and walk for 20 seconds or more
• Ability to answer the eligibility questions
• Ability to provide informed consent

Inclusion of Women and Minorities:

• Male and females of all races and ethnic groups are eligible

Exclusion Criteria:

• Currently receiving treatment for cancer
• Weight ≥ 300 lb (the balance system has a weight limit)
• Does not speak English
• Self-reports of hearing issues
• Pregnant females
• Inability or unwillingness of research participant to give written informed consent.

Study population will include 50 Adults survivors of childhood Acute Lymphoblastic Leukemia (ALL) enrolled on the SJLife protocol, and 50 healthy controls matched on age- and sex.