Kellie C. Huxel Bliven
Kellie Huxel Bliven and Karrie L. Hamstra-Wright
Karrie L. Hamstra-Wright and Kellie Huxel Bliven
The gluteus medius (GM) is thought to play an important role in stabilizing the pelvis and controlling femoral adduction and internal rotation during functional activity. GM weakness, resulting in decreased stabilization and control, has been suggested to be related to lower extremity dysfunction and injury. Many clinicians focus on strengthening the GM to improve lower extremity kinematics for the prevention and rehabilitation of injury. An indirect way to measure GM strength is through electromyography. It is generally assumed that exercises producing higher levels of activation will result in greater strengthening effects.3 Understanding what exercises result in the greatest level of GM activation will assist clinicians in their injury prevention and rehabilitation efforts.
Focused Clinical Question:
In a healthy adult population, what lower extremity exercises produce the greatest mean GM activation, expressed as a percentage of maximum voluntary isometric contraction?
Jessica R. Fairbairn and Kellie C. Huxel Bliven
Clinical Scenario: Until recently, injury epidemiology data on elite Paralympic athletes were limited. Current data suggest high rates of shoulder injury in wheelchair athletes. Differences in shoulder injury rates between sports have not been reported in this population. Clinical Question: Is the incidence of shoulder injury in elite wheelchair athletes different between sports? Summary of Key Findings: Shoulder injury rates are high in elite wheelchair athletes, particularly in sports such as field events and fencing that require a stable base (eg, trunk, core control) from which to perform. Wheelchair racing requires repetitive motions that contribute to shoulder injuries, but rates are lower than field sports and fencing. Wheelchair curling and sledge hockey have low shoulder injury risk. Clinical Bottom Line: Shoulder injury rates vary based on sport in elite wheelchair athletes. In addition to incorporating shoulder complex specific rehabilitation for overuse shoulder injuries, clinicians should focus on core and trunk stabilization in elite wheelchair athletes competing in sports, such as field events and fencing. Strength of Recommendation: Grade C evidence exists that reports shoulder injury rates among elite wheelchair athletes differ based on sport participation.
Kellie C. Huxel Bliven and Kelsey J. Picha
Kellie C. Huxel Bliven
Barton E. Anderson and Kellie C. Huxel Bliven
Research has shown a link between poor core stability and chronic, nonspecific low back pain, with data to suggest that alterations in core muscle activation patterns, breathing patterns, lung function, and diaphragm mechanics may occur. Traditional treatment approaches for chronic, nonspecific low back pain focus on exercise and manual therapy interventions, however it is not clear whether breathing exercises are effective in treating back pain.
Focused Clinical Question:
In adults with chronic, nonspecific low back pain, are breathing exercises effective in reducing pain, improving respiratory function, and/or health related quality of life?
Summary of Key Findings:
Following a literature search, 3 studies were identified for inclusion in the review. All reviewed studies were critically appraised at level 2 evidence and reported improvements in either low back pain or quality of life following breathing program intervention.
Clinical Bottom Line:
Exercise programs were shown to be effective in improving lung function, reducing back pain, and improving quality of life. Breathing program frequencies ranged from daily to 2–3 times per week, with durations ranging from 4 to 8 weeks. Based on these results, athletic trainers and physical therapists caring for patients with chronic, nonspecific low back pain should consider the inclusion of breathing exercises for the treatment of back pain when such treatments align with the clinician’s own judgment and clinical expertise and the patient’s preferences and values.
Strength of Recommendation:
Grade B evidence exists to support the use of breathing exercises in the treatment of chronic, nonspecific low back pain.
Kathleen A. Swanik, Kellie Huxel Bliven and Charles Buz Swanik
There are contradictory data on optimal muscle-activation strategies for restoring shoulder stability. Further investigation of neuromuscular-control strategies for glenohumeral-joint stability will guide clinicians in decisions regarding appropriate rehabilitation exercises.
To determine whether subscapularis, infraspinatus, and teres minor (anteroposterior force couple) muscle activation differ between 4 shoulder exercises and describe coactivation ratios and individual muscle-recruitment characteristics of rotator-cuff muscles throughout each shoulder exercise.
healthy, physically active men, age 20.55 ± 2.0 y.
4 rehabilitation exercises: pitchback, PNF D2 pattern with tubing, push-up plus, and slide board.
Main Outcomes Measures:
Mean coactivation level, coactivation-ratio patterns, and level (area) of muscle-activation patterns of the subscapularis, infraspinatus, and teres minor throughout each exercise.
Coactivation levels varied throughout each exercise. Subscapularis activity was consistently higher than that of the infraspinatus and teres minor combined at the start of each exercise and in end ranges of motion. Individual muscle-recruitment levels in the subscapularis were also different between exercises.
Results provide descriptive data for determining normative coactivation-ratio values for muscle recruitment for the functional exercises studied. Differences in subscapularis activation suggest a reliance to resist anteriorly directed forces.
Eric L. Sauers, Danelle L. Dykstra, R. Curtis Bay, Kellie Huxel Bliven and Alison R. Snyder
Throwing-related arm injuries are common in softball pitchers and may lead to diminished health-related quality of life (HRQOL). Arm symptoms such as pain have been reported to be more common in healthy overhead athletes than nonoverhead athletes. Furthermore, more frequent shoulder symptoms and lower shoulder function have been demonstrated in athletes with self-reported history of shoulder injury.
To evaluate the relationship between arm injury history, current pain rating, and HRQOL assessed via 2 region-specific patient self-report scales in high school and college softball pitchers.
High school and college athletic training facilities.
25 female softball pitchers (10 high school, 15 college; 18 ± 2 y, 169 ± 7.6 cm, 67.5 ± 10.3 kg).
Self-reported arm injury history and rating of current pain and HRQOL were collected during the late season.
Main Outcome Measures:
A self-report questionnaire of arm injury history and current pain rating was used, and HRQOL was assessed via 2 region-specific scales: the Disabilities of the Arm, Shoulder, and Hand (DASH) and the Functional Arm Scale for Throwers© (FAST©). Correlational analysis was used to evaluate the relationships between arm injury history, current pain rating, and the DASH total score and sport module and the FAST total score, pitching module, and subscales.
A history of arm injury from throwing was reported by 64% of participants, 31% of whom had to cease activity for more than 10 d. The most common site of arm time-loss injury was the shoulder (81%). Mild to severe shoulder pain during the competitive season was reported by 60% of respondents. The DASH and the FAST total scores were significantly correlated (r = .79, P < .001). Respondent rating of shoulder pain correlated significantly with the DASH total (r = .69) and sports module (r = .69) and the FAST total (r = .71), pitching module (r = .65), and pain (r = .73), impairment (r = .76), functional-limitation (r = .79), disability (r = .52), and societal-limitations (r = .46) subscales.
History of arm injury is common in female high school and college softball pitchers. Severe injury and elevated pain are associated with lower HRQOL that extends beyond the playing field.
Hannah Horris, Barton E. Anderson, R. Curtis Bay and Kellie C. Huxel Bliven
Context: Altered diaphragm function is linked to decreased core stabilization, postural changes, and decreased function. Two clinical tests used to assess breathing are the Hi-lo and lateral rib expansion (LRE) tests. It is currently unknown how breathing classification based on these tests differ and how their results are affected by varying test positions. Objective: To compare the results of breathing tests when conducted in varying test positions. Design: Prospective cross-sectional study. Setting: University laboratory. Participants: A total of 50 healthy adults (females 31 and males 29; age 29.3 [4.1] y; height 170.0 [10.4] cm; weight70.7 [15.1] kg). Intervention(s): Hi-lo and LRE tests in supine, seated, standing, and half-kneeling body positions. All tests were recorded and later scored by a single examiner. A generalized estimating equations approach with breathing test and body position as factors was used for analysis. Pairwise comparison with Bonferroni correction was used to adjust for multiple tests. Statistical significance was set at P = .05, 2 tailed. Main Outcome Measures: Hi-lo and LRE tests were scored based on the presence or absence of abdominal excursion, LRE, and superior rib cage migration. Following scoring, results were classified as functional or dysfunctional based on observation of these criteria. Results: A significant breathing test × test position interaction (P < .01) was noted, as well as main effects for test (P < .01) and test position (P < .01). All Hi-lo test positions identified significantly more dysfunctional breathers in positions of increased stability demand (P < .01), except between standing and half-kneeling positions (P = .52). In the LRE test, all positions were similar (P > .99) except for half-kneeling, which was significantly different from all other positions (P < .01). Conclusions: The Hi-lo test and LRE tests assess different breathing mechanics. Clinicians should use these tests in combination to gain a comprehensive understanding of a person’s breathing pattern. The Hi-lo test should be administered in multiple testing positions.