Furness J1, Pope R2
1Bond University, Physiotherapy, Gold Coast, Australia, 2Charles Sturt University, School of Community Health, Albury, Australia
Background: Injury epidemiology research reveals the knee to be an injury prone region within competitive surfers. Research supports the influence that hip strength has on knee alignment and subsequent injury. Given the high knee injury rates within competitive surfers, assessment of the segments above the site of injury such as the hips are warranted. Furthermore, it is theorized that long abductors and adductor muscles such as Sartorius, Gracilis, Medial Hamstrings and Tensor Fasciae Latae may provide mechanical support to the medial and lateral knee compartments. To date minimal scientific research has been conducted specific to the hip region in a competitive cohort.
Purpose: The primary aim of this study was to profile the isometric hip abductor and adductor muscle strength of competitive surfers using a clinical assessment method. A secondary aim was to compare the surfing cohort to a group of age matched recreational athletes.
Methods: A total 14 elite surfers (4 females; age 24.5±6.5 years; surf specific land based training 4.7±2.6 hours; weekly surfing frequency 11.6±4.5 hours) and 21 recreational athletes (4 females; age 25.3±2.7 years; land based training 5.9 ± 2.5 hours) participated in the study. Hip abduction and adduction isometric strength was measured using a hand-held dynamometer (HHD) in the supine position with the HHD placed on the medial aspect of the distal tibia for adduction and the lateral aspect for abduction. The recreational athlete group were significantly (p=0.03) heavier (71.3±8.3 vs. 80.0±12.4 kg) and therefore strength values were normalised based on body weight. Normalised force (newtons per kilogram, N/kg) and torque (newton meters per kilogram, Nm/kg) were derived and compared between groups. No significant differences were identified between sides and all values presented were the average of the dominant and non-dominant lower limb.
Results: Mean abduction scores for the competitive surfing cohort were as follows; 146.7±32.9 N, 113.9±26.6 Nm, 2.0±0.3 N/kg, 1.6±0.2 Nm/kg. Mean adduction scores were 131.7±29.9 N, 102.4±24.9 Nm, 1.8±0.3 N/kg, 1.4±0.2 Nm/kg. The adduction to abduction strength ratio was 0.9±0.1. A comparative analysis between the competitive surfers and the recreational athletes revealed no significant differences for normalised torque and force for abduction (1.6 vs. 1.6 Nm/kg; 2.0 vs. 2.1 N/kg, respectively). The competitive surfer group displayed significantly higher scores for normalised adduction (1.4 vs. 1.2 Nm/kg; p 0.01 and 1.8 vs. 1.6 N/kg; p=0.03, respectively). The surfer group exhibited an adduction to abduction strength ratio of 0.9 which was significantly (p 0.01) higher than the recreational athlete group (0.8).
Conclusion(s): An isometric strength profile of the hip abductors and adductors specific to a competitive surfing cohort has been presented. The competitive surfing cohort had significantly stronger adductors and consequently a higher adduction/ abduction ratio when compared with the recreational athlete group.
Implications: This study provides a baseline of isometric hip strength specific to competitive surfers who are involved in land based training and surfing. The findings may guide rehabilitation or be used as a bench mark to highlight deficiency. Further research is needed to determine how strength at the hip plays a role in injury prevention and performance enhancement.
Keywords: Surfing, hip, strength
Funding acknowledgements: This work was unfunded
Purpose: The primary aim of this study was to profile the isometric hip abductor and adductor muscle strength of competitive surfers using a clinical assessment method. A secondary aim was to compare the surfing cohort to a group of age matched recreational athletes.
Methods: A total 14 elite surfers (4 females; age 24.5±6.5 years; surf specific land based training 4.7±2.6 hours; weekly surfing frequency 11.6±4.5 hours) and 21 recreational athletes (4 females; age 25.3±2.7 years; land based training 5.9 ± 2.5 hours) participated in the study. Hip abduction and adduction isometric strength was measured using a hand-held dynamometer (HHD) in the supine position with the HHD placed on the medial aspect of the distal tibia for adduction and the lateral aspect for abduction. The recreational athlete group were significantly (p=0.03) heavier (71.3±8.3 vs. 80.0±12.4 kg) and therefore strength values were normalised based on body weight. Normalised force (newtons per kilogram, N/kg) and torque (newton meters per kilogram, Nm/kg) were derived and compared between groups. No significant differences were identified between sides and all values presented were the average of the dominant and non-dominant lower limb.
Results: Mean abduction scores for the competitive surfing cohort were as follows; 146.7±32.9 N, 113.9±26.6 Nm, 2.0±0.3 N/kg, 1.6±0.2 Nm/kg. Mean adduction scores were 131.7±29.9 N, 102.4±24.9 Nm, 1.8±0.3 N/kg, 1.4±0.2 Nm/kg. The adduction to abduction strength ratio was 0.9±0.1. A comparative analysis between the competitive surfers and the recreational athletes revealed no significant differences for normalised torque and force for abduction (1.6 vs. 1.6 Nm/kg; 2.0 vs. 2.1 N/kg, respectively). The competitive surfer group displayed significantly higher scores for normalised adduction (1.4 vs. 1.2 Nm/kg; p 0.01 and 1.8 vs. 1.6 N/kg; p=0.03, respectively). The surfer group exhibited an adduction to abduction strength ratio of 0.9 which was significantly (p 0.01) higher than the recreational athlete group (0.8).
Conclusion(s): An isometric strength profile of the hip abductors and adductors specific to a competitive surfing cohort has been presented. The competitive surfing cohort had significantly stronger adductors and consequently a higher adduction/ abduction ratio when compared with the recreational athlete group.
Implications: This study provides a baseline of isometric hip strength specific to competitive surfers who are involved in land based training and surfing. The findings may guide rehabilitation or be used as a bench mark to highlight deficiency. Further research is needed to determine how strength at the hip plays a role in injury prevention and performance enhancement.
Keywords: Surfing, hip, strength
Funding acknowledgements: This work was unfunded
Topic: Musculoskeletal: lower limb; Sport & sports injuries; Musculoskeletal
Ethics approval required: Yes
Institution: Bond University
Ethics committee: Bond University Human Research Ethics Committee
Ethics number: RO1610
All authors, affiliations and abstracts have been published as submitted.
