Increase the Speed of Your Adjustment Plyometric conditioning to recruit more “fast twitch” muscle fibres SAMPLE CASE A 35-year-old construction worker enters the clinic complaining of low back pain. The patient informs the doctor that the problem has been intermittent for the past 10 years, ever since he began construction work, and has steadily become worse over the past two years. He relays to the doctor that he has been to chiropractors in the past, but that many of those had a hard time adjusting him due to his larger frame. Physical examination re-veals a decreased lumbar range of motion in the extended position. Lumbar extension also reproduces the pain at its end range. Static and motion palpation reveal subluxations pres-ent at L4 and L5 on the right, with subsequent hypertonicity of the quadratus lumborum bilaterally. Neurological and X-ray analyses are unremarkable. The doctor is proficient in manual adjusting techniques, and is confident that (s)he will be able to effectively adjust the patient’s subluxations, regardless of the individual’s size. The doctor promptly places the patient in a side posture position and attempts to adjust the subluxated lumbar verte-brae. However, as the doctor takes his contacts, he notices that the individual’s frame has altered the doctor’s contact positioning, and finds it difficult to roll the patient into the proper thrusting position. Once the position is finally achieved, the doctor realizes that his thrust seems slow and weak for this patient, resulting in a sub-par adjustment. Has this ever happened to you? Have you ever had a difficult time adjusting a patient, or just felt as though your thrust lacked a certain speed or power? In this edition of Technique Toolbox, I will review two activities that will help develop a faster thrust, by implementing exercises that increase the recruitment of your “fast twitch” muscle fibres. MuSCLE FIBRE TYPES There are three main types of muscle fibres. Each one has its own characteristics and is suited to a particular type of movement. • Type I muscle fibres: These muscle fibres contract slowly (slow twitch), and can sustain muscular contractions for an extended period of time. This makes them ideal for endurance type of events. They contain large and numerous mitochon-dria, which aid in their oxidative metabolism. These fibres do not fatigue quick-ly; however, they are only able to produce a low level of force output. 1 • Type IIa muscle fibres: These muscle fibres are named fast twitch fibres. How-ever, they are in the middle of the muscle fibre spectrum, as they are less fatigue resistant, produce more muscular force, and contract at a faster speed than slow twitch fibres, but not quite as much as Type IIb fibres. 1 • The Type IIb muscle fibres: These muscle fibres are the most easily fatigued out of all the fibres, but also generate the most power. These are most heavily recruited for activities that require a large burst of power over a very short period of time. 1 These Type IIb muscle fibres are the fibres primarily recruited for your thrust. (Type IIa muscle fibres also play a small role.) Therefore, when conditioning to improve the speed of your thrust, it is the Type II muscle fibres, mostly ‘b’ but also ‘a’, that you should be targeting with your training. So, how do we recruit more of these Type II muscle fibres to produce a more effective thrust? The simplest way is to perform plyometric exercises that target the employment of the pectoralis and triceps muscles, the same muscles recruited in most chiropractic adjustments. EXERCISE 1: Depth Push-Ups (See photos 1-3) • Start in a “push-up” position with both arms in full extension, and both hands placed on www.canadianchiropractor.ca Dr. John Minardi is a 2001 graduate of Canadian Memorial Chiropractic College. A Thompson-certified practi-tioner and instructor, he is the cre-ator of the Thompson Technique Seminar Series and author of The Complete Thompson Textbook – Minardi Integrated Systems. in addi -tion to his busy lecture schedule, Dr. Minardi operates a successful pri-vate practice in Oakville, Ontario. E-mail [email protected], or visit www.ThompsonChiropractic Technique.com. John Minardi, BHK, DC 14 • Canadian ChiropraCtor | JULY/aUGUSt 2011
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