Neck strength and force in reaction time task of adolescent athletes with and without concussion history: A pilot study.

OBJECTIVES: Assess the impact of concussion by comparing reaction time, peak force recruitment, and rate of force development of adolescent athletes returning from concussion against age- and sex-matched controls in visual-elicited neck movement. DESIGN: Athletes sat secured in a custom-built isometric device with their heads secured in a helmet and attached to a 6-axis load cell. They performed neck flexion, extension, and lateral flexion in response to a visual cue. Three trials in each direction were used for statistical analyses; peak force and rate of force development were normalized against athlete mass. SETTING: Laboratory. PARTICIPANTS: 26 adolescent/young adult athletes (8F/18M), either recently concussed (and cleared for return to sport) or an age- and sex-matched healthy control. MAIN OUTCOME MEASURES: Reaction time, angle, standard deviation of angle, deviation from target angle, peak force, and RFD over 50, 100, 150,and 200 ms of movement were measured for each trial. RESULTS: Concussed athletes had decreased normalized peak force (P = 0.008) and rate of force development (P < 0.001-0.007). In neck extension, concussed athletes also had decreased movement precision (P = 0.012). CONCLUSIONS: Concussion is associated with alterations of neck biomechanics that decrease overall neck strength.

Surgical treatment of snapping proximal hamstring tendon syndrome: the resolution of snapping and excellent patient satisfaction.

Snapping proximal hamstring is an uncommon phenomenon, with few case reports documenting surgical treatment. The purpose of this study is to report snapping resolution, minimum 2-year post-operative patient-reported outcome (PRO), satisfaction scores and complications from patients who underwent surgical release of the conjoint tendon from the sacrotuberous ligament with reattachment to the ischial tuberosity. Prospectively collected data from two institutional databases were retrospectively reviewed for patients who underwent hamstring repair for partial- or full-thickness tears. Patients were included if they demonstrated 'snapping proximal hamstrings' on preoperative physical examination, including ultrasound confirmation, and repair subsequently performed. Patients were excluded if they had reconstruction of the proximal hamstring tendon or claimed worker's compensation. With a total of 20 patients (15 females and 5 males), successful resolution of snapping was reported in 100% of the cohort. For patients with pre- and post-surgical lower-extremity functional scores (LEFS), post-surgical LEFS were significantly higher than pre-surgical LEFS (pre-surgical: 17.0 ± 4.0, post-surgical: 73.6 ± 3.3, P < 0.001). Average post-operative PROs were as follows: International Hip Outcome Tool-12, 92.3 ± 8.3; modified Harris Hip Score, 93.2 ± 7.8; Non-arthritic Hip Score, 92.5 ± 6.8; Hip Outcome Score-Sports Specific Subscale, 94.4 ± 6.7; LEFS, 73.9 ± 3.4; and median visual analog scale of 0 with an interquartile range of 0-1. Patient satisfaction was 'very satisfied' in 19 (95%) patients and 'satisfied' in 1 (5%) patient. At a minimum 2-year follow-up, patients who underwent surgical treatment for chronic snapping of the proximal hamstrings demonstrated complete resolution of painful posterior snapping, reported high PROs and satisfaction, and had no reported post-operative complications.