The Anatomy of Sports Injuries, Second Edition

Your Illustrated Guide to Prevention, Diagnosis and Treatment

Brad Walker

• Publisher: Lotus Publishing
• Year: 2012
• Print ISBN: 9781905367382
• eBook ISBN: 9781623172848
• Topic: Medicine
• Subtopic: Diseases & Allergies

Everyone who plays sports experiences injuries. Many people never fully recover because they are not aware of what they can do to facilitate recovery. But there is no need to simply resign yourself to "living with" a sports injury. Author Brad Walker brings years of expertise—he works with elite-level and world-champion athletes, and lectures on injury prevention, to this fully updated and expanded edition of The Anatomy of Sports Injuries. The book takes a fundamental approach, bringing you inside the body to show exactly what is happening when a sports injury occurs. At the heart of The Anatomy of Sports Injuries are 300 full-colour anatomical illustrations that show the sports injury in detail, along with over 100 colour drawings of simple stretching, strengthening, and rehabilitation exercises that the reader can use to speed up the recovery process. The Anatomy of Sports Injuries is for every sports player or fitness enthusiast who has been injured and would like to know what the injury involves, how to rehabilitate the area, and how to prevent complications or injury in the future.

Chapter 1

Explanation of Sports Injury

No one doubts the benefits of regular structured exercise: elevated cardiovascular fitness, improved muscular strength and increased flexibility all contribute to an enhanced quality of life. However, one of the very few drawbacks of exercise is an increased susceptibility to sports injury.

While sport and exercise participation rates are increasing (a good thing!) injury rates are also on the rise. In fact the US Consumer Product Safety Commission estimates: “between 1991 and 1998, golf and swimming injuries increased 110 percent; ice hockey and weightlifting injuries, 75 percent; soccer injuries, 55 percent; bicycling, 45 percent; volleyball, 44 percent; and football 43 percent” (Consumer Product Safety Review, 2000).

What Constitutes a Sports Injury?

Physical injury generally can be defined as any stress on the body that prevents the organism from functioning properly and results in the body employing a process of repair. A sports injury can be further defined as any kind of injury, pain or physical damage that occurs as a result of sport, exercise or athletic activity.

Although the term sports injury can be used to define any trauma sustained as a result of sport and exercise, it usually describes injuries that affect the musculoskeletal system. More serious injuries, such as head, neck and spinal cord trauma, are usually considered separate to common sports injuries like sprains, strains, fractures and contusions.

What Is Affected in a Sports Injury?

Sports injuries are most commonly associated with the musculoskeletal system, which includes the muscles, bones, joints and associated tissues such as ligaments and tendons. Below is a brief explanation of the components that make up the musculoskeletal system.

Muscles

Muscle is composed of 75% water, 20% protein and 5% mineral salts, glycogen and fat. There are three types of muscle: skeletal, cardiac and smooth. The type of muscle involved with movement is skeletal (also referred to as striated, somatic or voluntary). Skeletal (somatic or voluntary) muscles make up approximately 40% of the total human body weight. Skeletal muscles are under voluntary control, and attach to, and cover over, the bony skeleton. They are capable of powerful, rapid contractions and longer, sustained contractions. Skeletal muscles enable us to perform both feats of strength and controlled, fine movements. They are attached to bone by tendons. The place where a muscle attaches to a relatively stationary point on a bone, either directly or via a tendon, is called the origin. When the muscle contracts, it transmits tension to the bones across one or more joints and movement occurs. The end of the muscle that attaches to the bone that moves is called the insertion.

Overview of Skeletal Muscle Structure

The functional unit of skeletal muscle is known as a muscle fiber, which is an elongated, cylindrical cell with multiple nuclei, ranging from 10–100 microns in width, and a few millimetres to 30+ centimetres in length. The cytoplasm of the fiber is called the sarcoplasm, which is encapsulated inside a cell membrane called the sarcolemma. A delicate membrane known as the endomysium surrounds each individual fiber.

Muscle fibers are grouped together in bundles covered by the perimysium. These bundles are themselves grouped together, and the whole muscle is encased in a sheath called the epimysium. These muscle membranes run through the entire length of the muscle, from the tendon of origin to the tendon of insertion. This whole structure is sometimes referred to as the musculo-tendinous unit.

NOTE: As they contract, all muscle types generate heat, and this heat is vitally important in maintaining a normal body temperature. It is estimated that 85% of all body heat is generated by muscle contractions.

Major muscles include the quadriceps of the thigh and the biceps brachii of the upper arm.

Bones

We are born with approximately 350 bones, but gradually they fuse together until by puberty we have only 206. Bones form the supporting structure of the body and are collectively known as the endoskeleton. (The exoskeleton is well developed in many invertebrates but exists in humans only as teeth, nails and hair). Fully developed bone is the hardest tissue in the body and is composed of 20% water, 30–40% organic matter and 40–50% inorganic matter.

Bone Development and Growth

The majority of bone is formed from a foundation of cartilage, which becomes calcified and then ossified to form true bone. This process occurs through the following four stages:

1. Bone building cells called osteoblasts become active during the second or third month of embryonic life.

2. Initially, the osteoblasts manufacture a matrix of material between the cells, which is rich in a fibrous protein called collagen. This collagen strengthens the tissue. Enzymes then enable calcium compounds to be deposited within the matrix.

3. This intercellular material hardens around the cells, which become osteocytes, living cells that maintain the bone but do not produce new bone.

4. Other cells called osteoclasts break down, remodel and repair bone. This process continues throughout life but slows down with advancing age. Consequently, the bones of elderly people are weaker and more fragile.

The structure of muscle tissue from microscopic to gross anatomy.

Bone development and growth.

In brief, osteoblasts and osteoclasts are the cells that lay down and break down bone respectively, enabling bones to very slowly adapt in shape and strength according to need.

Bone cells sit in cavities called lacunae (singular: lacuna) surrounded by circular layers of very hard matrix that contains calcium salts and larger amounts of collagen fibers. Bones protect internal organs and facilitate movement. Together they form a rigid structure called the skeleton. Major bones include the femur in the thigh and the humerus in the upper arm.

Types of Bone According to Density

Compact Bone

Compact bone is dense and looks smooth to the naked eye. Through the microscope, compact bone appears as an aggregation of Haversian systems called osteons. Each system is an elongated cylinder oriented along the long axis of the bone, consisting of a central Haversian canal containing blood vessels, lymph vessels and nerves surrounded by concentric plates of bone called lamellae. In other words, each Haversian system is a group of hollow tubes of bone matrix (lamellae) placed one inside the next. Between these lamellae there are spaces (lacunae) that contain lymph and osteocytes. The lacunae are linked via hair-like canals called canaliculi to the lymph vessels in the Haversian canal, enabling the osteocytes to obtain nourishment from the lymph. This tubular array of lamellae gives great strength to bone.

Structure of compact bone.

Structure of spongy (cancellous) bone.

Other canals called perforating, or Volkmann’s, canals run at right angles to the long axis of the bone, connecting the blood vessels and nerve supply within the bone to the periosteum.

Spongy Bone (Cancellous Bone)

Spongy bone is composed of small, needle-like trabeculae (singular: trabecula; literally, ‘little beams’) containing irregularly arranged lamellae and osteocytes interconnected by canaliculi. There are no Haversian systems but rather lots of open spaces, which can be thought of as large Haversian canals, giving a honeycombed appearance. These spaces are filled with red or yellow marrow and blood vessels.

This structure forms a dynamic lattice capable of gradual alteration through realignment ...

Table of contents

• Cover
• Full Title
• Copyright
• Contents
• Introduction
• Anatomical Directions
• Chapter 1
• Chapter 2
• Chapter 3
• Chapter 4
• Chapter 5
• Chapter 6
• Chapter 7
• Chapter 8
• Chapter 9
• Chapter 10
• Chapter 11
• Chapter 12
• Chapter 13
• Chapter 14
• Chapter 15
• Chapter 16
• Chapter 17
• Glossary of Terms
• Resources
• Index