Postural Control Mechanisms During Quiet Standing in Patients With Diabetic Sensory Neuropathy

Abstract

OBJECTIVE -The objective of the present study was to compare postural mechanisms identified by using dual force platform in healthy elderly community-dwelling subjects and diabetic sensory neuropathy (DSN) patients under different visual conditions. RESEARCH DESIGN AND METHODS -The presence and the severity of the sensory neuropathy was evaluated with a clinical scale. Postural mechanisms and motor strategies of the ankle and hip joints were quantified by testing subjects in quiet stance on a dual force platform under two visual conditions (eyes open and eyes closed). Root mean square (RMS) values of the center of pressure (COP) time-varying signals and normalized cross-correlation function were used to estimate the contribution and the interdependence of postural control mechanisms.RESULTS -DSN patients show larger RMS values of the COP net displacement in both anteroposterior and mediolateral (ML) directions. Motor strategies at the ankle joints are altered in DSN patients compared with healthy elderly subjects particularly in the ML direction.CONCLUSIONS -This experiment is the first to highlight that even with vision, postural mechanisms at the ankle joints are impaired in DSN patients during quiet standing. Our results point out the importance of focusing on postural control instability in ML of DSN patients. Diabetes Care 27:173-178, 2004T he postural control system is a complex organization that controls the orientation and the equilibrium of the body during an upright stance (1,2). Past research provides many insights that the postural control system involves sensory afferences integration instead of eliciting reflex responses. Sources of sensory afferences that are viewed to contribute to postural control are 1) vestibular, 2) visual, and 3) proprioceptive. Postural instability in diabetic sensory neuropathy (DSN) patients is usually attributed to the lack of accurate proprioceptive feedback (sensory ataxia) from the lower limbs (3-5). The prevalence of sensory ataxia in diabetic patients ranges from 10 to 90% depending on screening protocol and criteria to define neuropathy (6). Compared with non-neuropathic diabetic patients, DSN patients self-reported 15 times more injuries during gait and reported feeling less safe during unusual situations (7). Peripheral neuropathy has been significantly associated with falling and repetitive falls (8). Evaluation of postural steadiness is usually based on the interpretation of center of pressure (COP) measures using a force platform (9). Only few studies have addressed the problem of postural instability during quiet standing in DSN (3-5,10). High correlations were found between the severity of the neuropathy and the COP measures (5,10,11) but not with diabetes per se (3).Past reports on postural steadiness of DSN patients only quantify the net COP changes in anteroposterior (AP) and mediolateral (ML) directions. During feet side-side configuration, postural mechanisms have been reported (12) to be under ankle mechanism in AP direction, whereas hip abductors/addu...

Equilíbrio estático em pacientes com diabetes melito tipo 2 com ou sem polineuropatia diabética

“…This finding is similar to what was discovered by other authors, who stated that patients presenting peripheral neuropathy or DPN show balance alterations when contrasted with healthy subjects (15)(16)(17)(18)(21)(22)(23)(24)(25) and with subjects presenting DM without DPN (17,18,21,23,25). This statement is based on the fact that the tactile sensorial system is the main mechanism for balance (26); hence, when influenced by DPN, balance control is affected.…”

“…Former studies objectively appraise static balance through force platforms (15,(21)(22)(23). We used the WBB Static balance in diabetic polyneuropathy platform and have found results that agree with what is suggested by the literature.…”

“…This statement is based on the fact that the tactile sensorial system is the main mechanism for balance (26); hence, when influenced by DPN, balance control is affected. Furthermore, higher CoP displacement under the closed eyes condition has also been evidenced by other authors (15,17,23,25), who stated that eliminating the visual stimulus affects postural control.…”

“…A number of investigations has been carried out on the influence of DPN in the balance of subjects with DM. Higher CoP displacements have been observed in patients presenting DPN, in contrast with those presenting DM without DPN and healthy individuals (15)(16)(17). Furthermore, Ghanavati and cols.…”

Dynamic stability training improves standing balance control in neuropathic patients with type 2 diabetes

“…This increased risk is presumably due to the well-documented balance problems attributed to neuropathy [1] and sensory ataxia, which is the lack of accurate proprioceptive feedback [2]. Sources of instability in patients with type 2 DN include the loss or reduction of peripheral sensory information in the feet [3][4], the inability of the central nervous system (CNS) to appropriately integrate available postural control information [2,[4][5], and a switch from an ankle-based to a hip-based balance strategy [6][7][8][9][10]. In addition, an increase in the use of vestibular information and dependence on visual information [11] alter the style of postural control in patients with DN.…”