Core proprioception indicates likelihood of injury

[JasonE]

The following was sent out to Supertraining e-mail list group members last month:


The Effects of Core Proprioception on Knee Injury: A Prospective
Biomechanical-Epidemiological Study.Zazulak BT, Hewett TE, Reeves NP,
Goldberg B, Cholewicki J.

Am J Sports Med. 2007 Mar;35(3):368-373. Epub 2007 Jan 31.

BACKGROUND: In sports involving pivoting and landing, female athletes
suffer knee injury at a greater rate than male athletes. HYPOTHESES:
Proprioceptive deficits in control of the body's core may affect
dynamic stability of the knee. Female, but not male, athletes who
suffered a knee injury during a 3-year follow-up period would
demonstrate decreased core proprioception at baseline testing as
compared with uninjured athletes. STUDY DESIGN: Cohort study
(prognosis); Level of evidence, 2.

METHODS: Study subjects were 277 collegiate athletes (140 female, 137
male) who were prospectively tested for core proprioception by active
and passive proprioceptive repositioning. Athletes were monitored for
injury for 3 years. An ANOVA and multivariate logistic regression
were used to test whether core proprioception was related to knee
injuries in athletes.

RESULTS: Twenty-five athletes sustained knee injuries (11 women, 14
men). Deficits in active proprioceptive repositioning were observed
in women with knee injuries (2.2 degrees ) and ligament/meniscal
injuries (2.4 degrees ) compared with uninjured women (1.5 degrees ,
P </= .05). There were no differences in average active
proprioceptive repositioning error between injured men and uninjured
men (P >/= .05). Uninjured women demonstrated significantly less
average error in active proprioceptive repositioning than uninjured
men (1.5 degrees vs 1.7 degrees , P </= .05). For each degree
increase in average active proprioceptive repositioning error, a 2.9-
fold increase in the odds ratio of knee injury was observed, and a
3.3-fold increase in odds ratio of ligament/meniscal injury was
observed (P </= .01). Active proprioceptive repositioning predicted
knee injury status with 90% sensitivity and 56% specificity in female
athletes.

CONCLUSIONS: Impaired core proprioception, measured by active
proprioceptive repositioning of the trunk, predicted knee injury risk
in female, but not male, athletes.

CST's emphasis on movement quality - which requires the development of full-body proprioception and coordination, is validated once again by published research. As a fitness system, the PREHAB (injury prevention) benefits of CST are as yet unmatched!

[JasonE]

The following extracts were also sent to Supertraining e-mail list group members last month, and may also be of interest:


Below are relevant extracts:

Core stability, as generally defined in sports medicine literature,
is a foundation of trunk dynamic control that allows production,
transfer, and control of force and motion to distal segments of the
kinetic chain. For the purposes of this study, a more precise
operational definition was developed. Core stability was defined as
the body's capacity to maintain or resume a relative position of the
trunk after perturbation.

...Core proprioception was evaluated using a previously validated
apparatus as described by Taimela et al (Figure 1 ).23,24,33 The
apparatus was designed to produce passive motion of the lumbar spine
in the transverse plane. Subjects were positioned on this apparatus
so that the vertical pivot axis extended through the L4/L5 vertebrae.
The seat was driven by a stepper motor at a steady, slow rate to
minimize tactile cueing. The contribution of the vestibular system
was eliminated since the upper body remained fixed to the back-rest
with a 4-point seatbelt and the lower body moved in the plane
parallel to the ground. Care was taken to eliminate visual and
auditory cues of the apparatus motion. Therefore, this proprioception
test focused mainly on the feedback from muscular and articular
mechanoreceptors of the trunk.

Subjects were initially rotated 20&#176; away from the neutral spine
posture (at 2&#176; per second) and briefly held in that position for 3
seconds. In the passive test, the subjects were slowly rotated toward
the original position by the motor (at 1&#176; per second). In the active
test, the subject rotated himself or herself after the clutch was
disengaged from the motor drive. In both tests, the subjects stopped
the apparatus by pressing a switch when they perceived they were in
the original, neutral position. Each subject performed 4 practice
trials before each test, 2 in each direction. Subsequently, 5
randomized trials in each direction for each test were performed.

====================

The effect of lumbar fatigue on the ability to sense a change in
lumbar position. A controlled study.

Spine. 1999 Jul 1;24(13):1322-7.
Taimela S, Kankaanpaa M, Luoto S.

STUDY DESIGN: A cross-sectional study in patients with
recurrent/chronic low back trouble and healthy control subjects.
OBJECTIVE: To evaluate the effect of paraspinal muscle fatigue on the
ability to sense a change in lumbar position. SUMMARY OF BACKGROUND
DATA: Protection against spinal injury requires proper anticipation
of events, appropriate sensation of body position, and reasonable
muscular responses. Lumbar fatigue is known to delay lumbar muscle
responses to sudden loads. It is not known whether the delay is
because of failure in the sensation of position, output of the
response, or both.

METHODS: Altogether, 106 subjects (57 patients with low back trouble
[27 men and 30 women] and 49 healthy control subjects [28 men and 21
women]) participated in the study. Their ability to sense a change in
lumbar position while seated on a special trunk rotation unit was
assessed. A motor rotated the seat with an angular velocity of 1
degree per second. The task in the test involved reacting to the
perception of lumbar movement (rotation) by releasing a button with a
finger movement. The test was performed twice, before and immediately
after a fatiguing procedure. During the endurance task, the
participants performed upper trunk repetitive extensions against a
resistance, with a movement amplitude adjusted between 25 degrees
flexion and 5 degrees extension, until exhaustion.

RESULTS: Patients with chronic low back trouble had significantly
poorer ability than control subjects on the average to sense a change
in lumbar position (P = 0.007), which was noticed before and after
the fatiguing procedure. Lumbar fatigue induced significant
impairment in the sensation of position change (P < 0.000001).
CONCLUSIONS: Lumbar fatigue impairs the ability to sense a change in
lumbar position. This feature was found in patients and control
subjects, but patients with low back trouble had poorer ability to
sense a change in lumbar position than control subjects even when
they were not fatigued. There seems to be a period after a fatiguing
task during which the available information on lumbar position and
its changes is inaccurate.