Efficacy of Brock String Therapy Post Concussion

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University of Pittsburgh




Near Point Convergence
Concussion, Brain


Behavioral: Brock String Therapy
Behavioral: Standard of Care

Study type


Funder types




Details and patient eligibility


The purpose of the proposed study is to evaluate the efficacy of Brock String therapy prescribed in the acute stage of concussion recovery can improve clinical outcomes among patients with receded near point of convergence (NPC). Aim 1: Determine if participants receiving the Brock String have more significant improvements in NPC measurements at follow up 7-10 days post injury. Aim 2: Determine if participants receiving the Brock String 1) improve on computerized neurocognitive test scores from initial visit (<48 hours post injury) to follow up visit (7-10 days post injury) compared to control participants, and 2) have reduced recovery time (i.e., days from injury until return to play) compared to control participants.

Full description

Receded near point of convergence (NPC) is a common oculomotor deficit associated with numerous vision diagnoses, including convergence and accommodative insufficiencies, following sport-related concussion (SRC). Researchers have found associations with worse neurocognitive test scores, higher post-concussion symptom burden, and longer recovery among patients with receded NPC relative to concussion patients with normal NPC. Although oculomotor dysfunction may resolve spontaneously or improves with vision therapy exercises in the post-acute phase of recovery, it is unclear if early intervention can improve recovery outcomes. The Brock String is a cost effective and practical vision therapy exercise for congenital convergence insufficiency (CI), and initial research supports effectiveness with SRC patients who have receded NPC in the subacute phase of recovery (e.g., weeks to months post injury). Early vision therapy intervention may be efficacious in improving recovery times and reduce healthcare costs by eliminating later therapies for chronic deficits.


50 estimated patients




12 to 20 years old


No Healthy Volunteers

Inclusion criteria

  • Athletes who sustained a concussion during organized sport within past 48 hours
  • ages 12-20
  • at least one NPC measurement >10 centimeters at initial clinic evaluation.

Exclusion criteria

  • lack of access to a smart phone to receive text message prompts
  • vestibular disorder
  • seizure disorder
  • history of traumatic brain injury with imaging findings or brain surgery
  • history of 3+ concussions\
  • concussion within the past 6 months
  • history of developmental or intellectual disability
  • history of substance abuse
  • Patients will also be excluded from recruitment if the treating clinician feels the potential participant would be unable to tolerate Brock String therapy due to severe symptoms

Trial design

Primary purpose




Interventional model

Parallel Assignment


Double Blind

50 participants in 2 patient groups

Brock String
Experimental group
Participants will receive instruction on Brock String therapy after first clinic visit (<48 hours post) injury, and will complete home therapy exercise twice daily
Behavioral: Brock String Therapy
Standard of Care
Active Comparator group
Participants will receive standard of care (i.e., no Brock String therapy within the first week post injury) but will be informed they will receive any therapy deemed necessary at follow up visit 7-10 days post injury, consistent with standard of care
Behavioral: Standard of Care

Trial contacts and locations



Central trial contact

Alicia Trbovich, PhD; Cynthia Holland, MPH

Data sourced from clinicaltrials.gov

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