Southern California Naginata Federation

Note: The following material has been compiled and presented without markers and footnotes. A material source can be found at the end of the section.

"The Stretch Reflex"

When the muscle is stretched, so is the muscle spindle. The muscle spindle records the change in length (and how fast) and sends signals to the spine which convey this information. This triggers the "stretch reflex" (also called the "myotatic reflex") which attempts to resist the change in muscle length by causing the stretched muscle to contract. The more sudden the change in muscle length, the stronger the muscle contractions will be (plyometric, or "jump", training is based on this fact). This basic function of the muscle spindle helps to maintain muscle tone and to protect the body from injury.

One of the reasons for holding a stretch for a prolonged period of time is that as you hold the muscle in a stretched position, the muscle spindle habituates (becomes accustomed to the new length) and reduces its signaling. Gradually, you can train your stretch receptors to allow greater lengthening of the muscles.

Some sources suggest that with extensive training, the stretch reflex of certain muscles can be controlled so that there is little or no reflex contraction in response to a sudden stretch. While this type of control provides the opportunity for the greatest gains in flexibility, it also provides the greatest risk of injury if used improperly. Only consummate professional athletes and dancers at the top of their sport (or art) are believed to actually possess this level of muscular control.

"Components of the Stretch Reflex"

The stretch reflex has both a dynamic component and a static component. The static component of the stretch reflex persists as long as the muscle is being stretched. The dynamic component of the stretch reflex (which can be very powerful) lasts for only a moment and is in response to the initial sudden increase in muscle length. The reason that the stretch reflex has two components is because there are actually two kinds of intrafusal muscle fibers: "nuclear chain fibers", which are responsible for the static component; and "nuclear bag fibers", which are responsible for the dynamic component.

Nuclear chain fibers are long and thin, and lengthen steadily when stretched. When these fibers are stretched, the stretch reflex nerves increase their firing rates (signaling) as their length steadily increases. This is the static component of the stretch reflex.

Nuclear bag fibers bulge out at the middle, where they are the most elastic. The stretch-sensing nerve ending for these fibers is wrapped around this middle area, which lengthens rapidly when the fiber is stretched. The outer-middle areas, in contrast, act like they are filled with viscous fluid; they resist fast stretching, then gradually extend under prolonged tension. So, when a fast stretch is demanded of these fibers, the middle takes most of the stretch at first; then, as the outer-middle parts extend, the middle can shorten somewhat. So the nerve that senses stretching in these fibers fires rapidly with the onset of a fast stretch, then slows as the middle section of the fiber is allowed to shorten again. This is the dynamic component of the stretch reflex: a strong signal to contract at the onset of a rapid increase in muscle length, followed by slightly "higher than normal" signaling which gradually decreases as the rate of change of the muscle length decreases.

Daily reality

Whew! That was a lot of physiology 101 mumbo jumbo. But, now that the "why does it work that way" portion has been re-visited in some small detail, we can touch on some things that many of us consider more "at-hand and user oriented".

Snap, Crackle, Pop

This Snap, Crackle, Pop is not coming from that bowl beneath your morning paper. No, suddenly, in the middle of a game or workout you hear it coming from inside a limb. It's alarming. But does it signal something serious, like a sprain, break, or tendon tear......or does it sound worse than it is?

According to the Penn State Sports Medicine Newsletter, noises around a joint are usually the result of "crepitus" (the rubbing of bone fragments), pressure changes, or ligaments making harmless contact. They're nothing to worry about if they're not quickly followed by pain. Nasty injuries, however, often produce ominous special audio effects. Here is the Penn State experts' guide to the sound track of injuries:

• Tendinitis: Creaking when straightening the foot can be a sign of flexor and extensor tendinitis, although it may also reflect Achilles tendinitis. Wrist tendinitis often is accompanied by a crackling sound.

• Sprained Ankles: A tearing, pop or snap may be the klaxon for a severe ankle sprain, usually the result of ligaments tearing.

• Knees: The knees can be a virtual rhythm section. Injuries to the meniscus (the disc-shaped cartilage under the kneecap) often gives a click. Front-of-the-knee problems crunch or crackle. (But occasional crackling may just mean you're not as young as you used to be.)

• Shoulders: A snap with severe pain can be a symptom of a tear in the long-head tendon of the biceps. If the shoulder moves out of the socket and then back in, you may experience a popping sensation but no definite sound. A shoulder strain may be accompanied by crepitus noises if you press on the painful area.

Sprains and Strains

• A Strain is not a Sprain, although they may occur at the same time.
  
• A Sprain means that the ligaments that hold the bones together have suffered tears.
  
• A Strain is an injury of a muscle which has been stretched too far, too fast resulting in a tear of the muscle itself and the tissue that supports it.

Knees and ankles are the two joints most commonly sprained, but any joint can be affected. Symptoms of a sprain may include:

1. Pain (mild to severe) at the time of injury.
   
2. A "popping" sound may be heard.
   
3. Rapid discoloration of the skin.
   
4. Intensified pain with pressure or movement of the joint.
   
5. Swelling, often beginning within minutes of the injury.

If the joint is out of alignment, a dislocation or fracture may also have occurred.

Prevention of sprains primarily rests on limiting activities that require sudden, unexpected changes in the use of a joint. However, this advice may be too limiting, especially for people who are very physically active. An eight year study by Wake Forest University Baptist Medical Center concluded bracing to be more effective than taping to avoid ankle sprain.

Sprains can be very mild, requiring only the simple measures for recovery to take place. The main goals of the following measures is to prevent further injury and decrease the pain often caused by swelling:

1. Intermittent application of ice to the area for the first 24 to 48 hours following the injury.
   
2. Keeping the part elevated to decrease swelling.
   
3. Minimize use of the joint.
   
4. Use of anti-inflammatory medication such as aspirin or ibuprofen.

Sprains can also be very severe when there has been a lot of tearing or rupture of a ligament. These injuries may require, in addition to the above, immobilization of the joint. Partial immobilization can be accomplished with the use of splints and bandaging. However, more complete immobilization may require the use of a cast.

Ligaments have poor blood supply and therefore heal slowly. The healing process continues long after the symptoms of the injury have gone away.

Strains also have levels of severity. Strains may be minor (as with microscopic tears) or major, such as ruptures of the muscle. The severity is often related to the amount of pain that results.

Symptoms of strains may include:

1. Pain at the site of injury, when injury occurs.
   
2. Pain and tenderness following the injury.
   
3. Swelling and increased warmth at the site of the injury.
   
4. Stiffness that may occur within 24 hours following the injury.
   
5. Discoloration of the skin (often related to tearing of nearby blood vessels).
   
6. Lack of muscle power, if the muscle has been ruptured.

Common care for minor strains often include:

1. Not using the muscle while pain lasts.
   
2. Applying ice to the injured muscle.
   
3. Taking anti-inflammatory drugs like aspirin or ibuprofen.

Minor strains usually resolve within a few days. Severe cases, when the muscle has ruptured, may require surgery.

In any event, in order to make an informed decision about your health and medical care, be sure to ask your physician to fully explain the benefits, risks and costs of all treatment alternatives.

Stretching

A study from Brigham Young University in Hawaii recently found that stretching can build muscle strength. Subjects who performed a 40 minute stretching routine three times per week increased their leg strength by an average of 17 percent after 12 weeks - without weight training. "If you combine stretching with weight training, you should have greater strength gains than with either one alone, says Joke Kokkonen, Ph.D., study author.

The types of stretches that we do are indicative of the type of activity we find ourselves primarily engaged in. There are, of course, a number of stretches that can be helpful across the board. The main consideration is flexibility, and in order to have more flexible muscles, you need to perform a stretching routine three to four times per week. Start with aerobics or walking for five minutes to warm up. Then stretch slowly and deliberately, and hold each stretch for 15 to 30 seconds (DO NOT bounce while stretching).

The following are some good cross-training stretches, however, your own sport may include many variations. The goals are the same; to be stronger, limber, and prevent needless injury.

Quadriceps stretch

• Avoid this stretch if you have knee problems. While standing, brace your left hand against a wall. Lift your left foot behind you and grab it with your right hand, and try to pull your heel right to your buttocks. Repeat, switching both arms and legs.

• Lie on your right side and rest your head in your right palm. Grasp your left ankle - keep your right knee slightly bent for balance - and pull it up behind (but not touching) the buttocks. Turn over and repeat.

Standing half lotus

• Raise your right leg and rest your heel on a waist-high platform. Keeping both legs straight, hold your right ankle and slowly lower your chest to your thighs. Repeat with your left leg.

Calf stretch

• Grasp the handrail on a stairway, and position the ball of your right foot on the edge of a step. Raise your left foot slightly. Slowly lower your right heel. Repeat, stretching your left calf.

• Lean against a wall with your arms out straight and your palms against the wall's surface. Place one leg forward and bend your knee; keep the back leg straight and your heel on the floor. Lean toward the wall while slowly stretching your calf. Repeat with the other leg.

Arm circles

• Raise your arms to shoulder height. Slowly circle your arms clockwise for five to ten revolutions - wide circles - then do five to ten counterclockwise.

Triceps stretch

• Raise your left arm above your shoulder. Bend it at a 45 degree angle and rest your palm near the base of your neck. Next, place your right palm on your left elbow. Gently pull your left arm behind your head until you feel the stretch in your triceps. Switch arms and repeat.

Chest stretch

• Clasp your hands behind your back, then lift your arms up until you feel a good stretch through the chest, shoulders, and arms. Keep your legs shoulder-width apart with your knees slightly bent.

Spread-leg sit and reach

• Sit on the floor with your legs extended wide. With your arms above your head, slowly bend at the waist. Stop when you begin to arch your back.
  
• Sit and reach: In the same position, bend forward at the waist (with your back straight) and try to touch the toes on both feet simultaneously. If you can't, just reach for your shins.
  
• Modified sit and reach: Sit on the floor with your left leg extended forward and the sole of your right foot against your left thigh. Keeping your left leg straight, lower your chest toward your left knee and reach for your left shin with both hands. Repeat with your right leg.

Lower back

• Drop onto your hands and knees, with your shoulders directly over your hands. Keeping your hands in place and arms straight, sit back on your heels and hold for thirty seconds. If done correctly, you'll feel the stretch in your lower back.

Hamstring stretch

• Sit on the floor with legs straight, feet upright, and your heels no more than six inches apart. Bend forward from the hips and reach for your toes. Hold the stretch.

Spine twist

• Sit on the floor with your legs straight. Leaning on your right arm for support, cross your right leg over your left. Next, bend your right leg so that your foot is outside your left knee, resting on the floor. Place your left hand on your right knee, then slowly twist your upper body, looking over your right shoulder while pulling the knee in the opposite direction. Hold, then switch legs and repeat on the opposite side.

Groin stretch

• Sit on the floor and put the soles of your feet together, then grab your ankles. Gently pull your heels toward your groin area.

Naginata Shugyo P.O. Box 32212 Aurora, CO 80041

• "Sport Stretch", by Michael J. Alter
  
• "Stretching Scientifically", by Tom Kurz
  
• "SynerStretch for Total Body Flexibility", from "Health for Life"
  
• "The Health for Life Training Advisor", from "Health for Life"
  
• "Mobility Training for the Martial Arts", by Tony Gummerson
  
• "Stretch and Strengthen", by Judy Alter
  
• "Science of Stretching", by Michael J. Alter
  
• "Stretching", by Bob Anderson
  
• "Stretching for All Sports", by John E. Bealieu
  
• "Stretching without Pain", by W. Paul Blakey
  
• "The Muscle Book", by W. Paul Blakey
  
• "Stretching for Athletics", by Pat Croce
  
• "Extension: The 20-minute-a-day, Yoga-based program to relax, release, and rejuvenate the average stressed-out over-35-year-old-body", by Sam Dworkis with Peg Moline
  
• "Ultimate Fitness Through Martial Arts", by Sang H. Kim
  
• "The Woman's Stretching Book", by Susan L. Peterson
  
• "Staying Supple: The Bountiful Pleasures of Stretching", by John Jerome
  
• "Colliers Encyclopedia"
  
• "Complete Stretching", by Maxine Tobias and John Patrick Sullivan
  

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