Donald Neumann

Kinesiology of the Hip: A Focus on Muscular Actions

The 21 muscles that cross the hip provide both triplanar movement and stability between the femur and acetabulum. The primary intent of this clinical commentary is to review and discuss the current understanding of the specific actions of the hip muscles. Analysis of their actions is based primarily on the spatial orientation of the muscles relative to the axes of rotation at the hip. The discussion of muscle actions is organized according to the 3 cardinal planes of motion. Actions are considered from both femoral-on-pelvic and pelvic-on-femoral perspectives, with particular attention to the role of coactivation of trunk muscles. Additional attention is paid to the biomechanical variables that alter the effectiveness, force, and torque of a given muscle action. The role of certain muscles in generating compression force at the hip is also presented. Throughout the commentary, the kinesiology of the muscles of the hip are considered primarily from normal but also pathological perspectives, supplemented with several clinically relevant scenarios. This overview should serve as a foundation for understanding the assessment and treatment of musculoskeletal impairments that involve not only the hip, but also the adjacent low back and knee regions.

The effects of load placement on the EMG activity of the low back muscles during load carrying by men and women

An electromyographic (EMG) study of the lumbar paraspinal muscles during load carrying was undertaken in a group of 24 healthy subjects, 12 male and 12 female. Two different magnitude loads (10% and 20% of the subjects body weight) and four different carrying positions were compared with walking without an external load. Results indicated changes in back muscle activity showing a significant interaction between load magnitude and carrying position. Compared to walking without an external load, lumbar paraspinal EMG activity showed slight decreases when loads were carried in a backpack position or in the hand ipsilateral to the muscle. EMG activity contralateral to the hand carrying the load was significantly increased. Significant increases occurred when loads were carried anterior to the chest with the arms and a significant difference was found between male and female subjects for this carrying position. These findings have implications for the selection of carrying methods.

A proposed novel function of the psoas minor revealed through cadaver dissection.

There is sparse information about the anatomy and function of the psoas minor, specifically the extent and frequency to which the muscle attaches into the iliac fascia that drapes over the iliopsoas. This information may help clarify the function of the psoas minor, especially regarding the possibility of controlling the position and mechanical stability of the underlying iliopsoas. This descriptive, semiquantitative cadaveric study sought to clarify the gross anatomic detail of the psoas minor, particularly the muscles distal attachments. Thirty‐two embalmed cadaver hips were examined. Hips that presented with a psoas minor underwent further anatomic measurements. The psoas minor was present in 65.6% of the 32 hips. All of the psoas minor tendons attached firmly into iliac fascia, while 90.5% also had a firm bony attachment to the pelvis. On average, the muscle belly occupied the proximal 37.5 ± 6.0% of the entire musculotendinous unit, while the muscle bellys average anatomical cross‐sectional area was 52.5 ± 34.3 mm2. The psoas minors firm and consistent distal tendinous attachment into the iliac fascia may allow this muscle to partially control the position and mechanical stability of the underlying iliopsoas as it crosses the femoral head and adjacent regions. This hypothesized function may be clinically related to inflammation and pathology involving the iliopsoas tendon and adjacent tissues in the anterior region of the hip. Further study is now warranted to determine the clinical relevancy and biomechanical validity of this proposed function of the psoas minor. Clin. Anat. 28:243–252, 2015.

Joint deformity and dysfunction: a basic review of underlying mechanisms.

Five common examples of joint deformity or dysfunction were presented. In each case, abnormal biomechanics were caused by or associated with arthritis or arthrosis due to advanced age or overused joints. The principles described for each example can be applied to essentially all synovial joints in the body. Understanding the underlying pathologic and biomechanical mechanisms that cause joint dysfunction can enhance treatment and patient education programs.

Fundamental and Clinical Considerations of the Muscles of the Hip

This chapter will provide an overview of the actions of hip muscles, with a focus on understanding a muscle’s action based on its line-of-force. Discussions will highlight on how the position of the hip at a given time affects the torque and ultimate action of certain hip muscles. Other mechanical aspects of hip muscle function will be discussed, such as how the forces generated by muscle contraction affect the stress on the hip and its periarticular tissues. This chapter should serve as a foundation for physicians and rehabilitation specialists who direct and provide care for patients following hip arthroscopic surgery.

April 2014 Book Reviews

JOSPT offers invited reviews of current titles. The April 2014 column includes 5 reviews of the following books: The Use of Aquatics in Orthopedic and Sports Medicine Rehabilitation and Physical Conditioning; Clinical Mechanics and Kinesiology (With Web Resource); Anatomy: An Essential Textbook; Articular Cartilage Injury of the Knee: Basic Science to Surgical Repair; and Muscle Injuries in Sports. J Orthop Sports Phys Ther 2014;44(4):314–317. doi:10.2519/jospt.2014.44.4.314

October 2012 Book Reviews

JOSPT offers invited reviews of current titles. The October 2012 column includes 5 reviews of the following books: Physical Therapy Management of Low Back Pain: A Case-Based Approach; Kinesiology Taping: Fundamentals; Therapeutic Exercise: From Theory to Practice; Orthopaedic Manual Therapy Diagnosis: Spine and Temporomandibular Joints; and Pocket Orthopaedics: Evidence-Based Survival Guide. J Orthop Sports Phys Ther 2012;42(10):888–891. doi:10.2519/jospt.2012.42.10.888

October 2011 Book Reviews

JOSPT offers invited reviews of current titles. The October 2011 column includes 5 reviews of the following books: Athletic and Sports Issues in Musculoskeletal Rehabilitation; Biomechanics of Human Motion: Basics and Beyond for the Health Professions; Nerve and Vascular Injuries in Sports Medicine; Assessment and Treatment of Muscle Imbalance: The Janda Approach; and Ther Ex Notes: Clinical Pocket Guide. J Orthop Sports Phys Ther 2011;41(10):797–801. doi:10.2519/jospt.2011.41.10.797

October 2009 Book Reviews

The JOSPT offers invited reviews of current titles. The October 2009 column includes 8 reviews of the following books: Sports Medicine and Rehabilitation: A Sport-Specific Approach, Second Edition; Kinesiology: The Mechanics and Pathomechanics of Human Movement, Second Edition; Pharmacology for the Physical Therapist; Teaching Atlas of Musculoskeletal Imaging; Spine Surgery: Tricks of the Trade, Second Edition; Save Your Hands: The Complete Guide to Injury Prevention and Ergonomics for Manual Therapists, Second Edition; Orthopedic Oncology: Diagnostic and Treatment; and Clinical Tests for the Musculoskeletal System: Examinations-Signs-Phenomena. J Orthop Sports Phys Ther 2009;39(10):767–771. doi:10.2519/jospt.2009.39.10.767

July 2009 Book Reviews

The JOSPT offers invited reviews of current titles. The March 2009 column includes 6 reviews of the following books: Synopsis of Spine Surgery; Spinal Cord Injuries: Management and Rehabilitation; Essentials of Kinesiology for the Physical Therapist Assistant; Imaging in Rehabilitation; Musculoskeletal Manual Medicine: Diagnosis and Treatment; and Dictionary of Orthopedic Terminology. J Orthop Sports Phys Ther 2009;39(7):561–564. doi:10.2519/jospt.2009.39.7.561